Imaging Pediatric Hi1
of Mediastinal
Sandra
G. Kirchner,
Marta
Hernanz-Schulman,
Sharon
M.
Stein,
PeterF.
Wright,
Richard
M.
MD
MD MD
Heller,
MD
can
present
Histoplasmosis masses
MD
of lymph
nodes,
a diagnostic invasive
dilemma
mediastinal
if unusually fibrosis,
large
or pericarditis
result from the infection. These rare, late sequelae are often first suspected from findings on chest radiographs obtained for unrelated reaSons. Organisms are not always evident at histologic analysis at this stage. Mediastinal granulomas consist of lobulated masses of enlarged lymph nodes with central caseation, a peripheral thin capsule, and, occasionally,
calcification.
The
mass
does
not
invade
or
compromise
adjacent anatomic structures. Mediastinal fibrosis invades and can Seriously compromise the function of the tracheobronchial tree, superior vena cava, pulmonary arteries and veins, and esophagus; its symptoms mimic those of many other disorders. Pericarditis is commonly accompanied by pericardial effusion, pneumonia, and adenopathy. Although the radiologic findings of these conditions are nonspecific, they can be used with the clinical findings to suggest a diagnosis. Complications of histoplasmosis should be included in the differential diagnosis for patients residing in areas endemic to Histoplasma capsulatum. U INTRODUCTION Histoplasmosis is usually
a self-limited
disease
that
rarely
requires
therapy
in chil-
other than the very young or immunocompromised patient. However, complications can occur and are usually related to enlarged lymph nodes, the healing process, or dissemination. When the mediastinum is involved, formation of large dren
Abbreviation: Index
PAS
terms:
diastinitis,
Children, 67.2053
RadloGraphics i
From
M.H.S., sity
the
January requests cpsNA
system, fibrosis,
and 1 161
revision
the 21st
Histoplasmosis,
67.2053 67.273
67.2053
#{149}
#{149} Pericarditis,
#{149} Lung,
infection,
67.2053
#{149} Me-
5 1.2053
1
of Radiology
R.M.H.), 1991;
respiratory
1 1 :365-38
Department Center,
24,
acid-Schiff
#{149} Mediastinum,
1991;
S.M.S.,
Medical
periodic
and
Radiological
Department Ave
requested
of Pediatrics,
Sciences, Section
S, Nashville,
TN 37232-2675.
February
12 and received
MCN
D-1 120,
Section
oflnfectious From February
the 27;
Diseases 1990
RSNA
accepted
of Pediatric
Radiology
(P.F.W.),
Vanderbilt
scientific February
assembly. 28.
Address
(S.G.K., UniverReceived reprint
to S.G.K. 1991
365
Figure 1. Distribution of histoplasmosis worldwide. For both the map of the United States and the world, the key indicates the percentage of reactions to a histoplasmm skin test. (Reprinted, with permission, from references 1 and 3.)
granulomas or, less sis can be present.
often,
progressive
fibro-
The
states (1). Katherine
Dodd
U PATHOGENESIS AND CLINICAL CHARACTERISTICS
this is not possible, serologic testing (cornplement fixation or serum immunodiffusion) may provide the diagnosis. In an endemic area, the histoplasmin test may be unreliable as an indicator of acute disease related to H
,
OF
HISTOPLASMOSIS
Histoplasmosis
is caused by Histoplasma a fungal organism that usually infects the individual by way of the respiratory tract. In the United States, histoplasmosis is most prevalent in the major river valcapsulatum,
U
and southern Tomkins and
authors present the radiologic specof mediastinal histoplasmosis seen in a population of children with histoplasmosis treated at a large referral center during a 20year period. The use of a variety of imaging modalities including conventional radiography, tomography, bronchography, arteriography, ultrasound (US), computed tomography (CT) and magnetic resonance (MR) imaging is illustrated. trum
366
leys of the central Indeed, Drs Edna
RadioGraphics
U
Kirchner
Ct
al
made
the
first
antemortem
diagnosis
of
histoplasmosis in Nashville, Tennessee, in 1 932 (2), when they identified the organism in the peripheral blood monocytes of one of their patients. Histoplasmosis is also prevalent in 60 other countries (Fig 1) (3). Today, the diagnosis is made on the basis of cultures of the organism from affected tissue or identification of the yeast forms stained Gomori
with periodic methenamine
acid-Schiff silver (Fig
(PAS) or 2) When .
capsulatum.
In most patients, histoplasmosis is asymptomatic, and the infection is self-limited;
Volume
11
Number
3
a. b. Figure 2. (a) Photomicrograph (original magnIfication, 1,000 X 2.5; cotton phenol blue stain) of mycehal form of H capsulatum In tissue culture shows tuberculated macroconidium. (b) Photomicrograph (original magnification, 400 X 2.5; PAS stain) of H capsulatum in bone marrow section shows intracellular yeast forms in macrophages.
Inhalation
of H Capsulatum
Spores
into Aveoli Symptomatic
Asymptornatic
I
Dissemination
Regional
lymphadenopathy Pneumonltis
Nonsegmental
_
/N Resolution
Histoplasmoma
Resolution nodes with or without calcification Residual
Mediastinal
granuloma
Mediastinal
fIbrosis
Figure 3. Diagram outcomes of primary
outlines the histoplasmo-
sis in children. obstruction vena cava and azygos vein superior
pulmonary and veinb
arteries
bronchi
esophagus
Pericarditis
when
symptoms
nonspecific malaise (4). companied
do occur,
and include The initial by hilar
they
or mediastinal
enopathy
and
ofwhich
can
be seen
on chest
These
findings
usually
resolve
weeks
to months.
May
1991
are
generally
fever, cough, and infection may be ac-
peripheral
lymphad-
pneumonitis,
Medlastinal
mediastinal fibrosis, and pericarditis are rare, late sequelae of mediastinal histoplasmosis. Possible outcomes of primary histoplasmosis in children are outlined in Figure 3.
both
radiographs.
over
several
granulorna,
Kirchner
et al
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367
Figure 4. Histologic section (original magnification, 10 X 2.5; hematoxylin-eosin stain) of a lymph node involved with H cap. sulatum shows the majority of the node to be effaced by caseous granulomas.
a.
b.
5. Case 1. Posteroanterior (a) and lateral (b) chest radiographs show upper lobe area from a prior biopsy. Bilateral hilar and mediastinal adenopathy diffuse, nodular pulmonary infiltrates. Figure
U MEDIASTINAL GRANULOMA Mediastinal granuloma is an uncommon complication of primary histoplasmosis that usually becomes clinically apparent at some time remote from the initial infection. In children, the granuloma is often identified on chest radiographs obtained for unrelated reasons. The involvement of adjacent struc-
tures
is minimal,
U
Kirchner
et al
minor
consists
of a
lobulated mass of lymph nodes several centimeters in thickness, surrounded by a thin capsule (5) Histologic examination of the involved nodes shows varying degrees of central caseation, and calcification will occa.
be present
cent anatomic compression,
#{149}RadioGraphics
sutures in the left associated with
few or only
symptoms are present (5). The mediastinal granuloma
sionally
368
and
surgical is seen,
(Fig
structures if present,
4).
Invasion
of adja-
is not present, is minor.
Volume
11
Number
and
3
b.
a
Figure 6. Case 2. (a) Posteroanterior radiograph of the chest reveals a large, primarily right-sided paratracheal mass that compromises the lumen of the trachea and the right and left main stem bronchi. (b) Contrast material-enhanced CT scans of the chest reveal a large mediastinal mass that involves the right paratracheal area, surrounds the right main stem bronchus, and extends approximately 3 cm below the carina. The mass is inhomogeneous in attenuation and contains small calcifications.
Illustrative Cases.-In case 1 a 3-year-old girl was admitted to the hospital with recurrent cough and fever related to histoplasmosis. She had been admitted to another hospital 1 2 months previously with fever of unknown origin. Thorough evaluation revealed no cause for the chest radiographic findings of hilar and mediastinal adenopathy and pulmonary infiltrate (Fig 5). Histologic examination of biopsy specimens from the mediastinal lymph nodes and lung showed multiple caseating granulomas; yeast forms were seen with special stains. Serologic testing was positive for histoplasmosis, and cultures were positive for H capsulatum. Treatment with ketoconazole was begun. The child had no symptoms at follow-up examination 8 months later, and the medication was discontinued. However, her chest radiograph showed no improvement. In case 2, a 3-year-old child with asthma ,
was
May
admitted
1991
to the hospital
because
diastinal mass noted on a chest radiograph taken because of congestion and fever (Fig 6a) CT scans revealed a large inhomogeneous mass, containing calcifications (Fig 6b). The diagnosis of histoplasmosis was made on .
the basis of calcification adenopathy, negative test,
positive
results
in the paratracheal results of a tuberculin of a histoplasmin
and immunodiffusion
studies
test,
positive
for
histoplasmosis. The youngster underwent surgical resection of the right paratracheal mass and received amphotericin B. No evidence of fungus could be found in the specimen of granulomatous tissue. Follow-up chest radiographs revealed a small residual paratracheal mass. The child fared well except
for
recurrent
asthmatic
attacks.
of a me-
Kirchner
et al
#{149}RadioGrapbics
U
369
a.
b.
Figure 7. Case 3. (a) Posteroanterior chest radiograph shows a large paratracheal mass on the right. No calcifications are seen within the mass. (b) Contrast-enhanced CT scans show a large right-sided paratracheal mass with minimal tracheal deviation and compression. No calcification is identified within the mass.
cheal
findings resolved entirely over a 2-month penod. An esophagogram obtained 4 months later showed the formation of a traction diverticulum (Fig 8c).
granuloma. No organisms were tissue cultures or in specimens
Although mediastinal fibrosis occurs less frequently than mediastinal granuloma, it is a much more severe complication of histoplasmosis (4) The fibrotic mass of tissue, rather than just compressing adjacent anatomic
In case 3, a 14-year-old patient was admitted to the pediatric surgical service with a history
of cough
and
a right-sided
paratra-
mass detected at chest radiography and CT (Fig 7). The likely diagnosis was thought to be histoplasmosis because of positive results from a histoplasmin test and negative results from a tuberculin test. Biopsy of the paratracheal mass revealed a fibrocaseous
methenamine stains. azole.
The
silver patient
nitrate was
and
treated
In case
identified stained
in with
acid-fast with
ketocon-
4, a 1 5-year-old patient was refever, pleuritic chest pain, and a subcarmnal mass detected on the initial chest radiograph (Fig 8a) A barium swallow study showed that the esophagus was displaced and compressed by the mass, and the tracheal bifurcation was also broadened (Fig 8b). Cultures of the pleural fluid were negative for H capsulatum. Results of the tuberculin test were also negative, while those of the histoplasmin test and complement fixation tests were positive. The chest radiographic ferred
for
.
370
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MEDIASTINAL
FIBROSIS
.
structures,
gradually
invades
them
and
se-
verely compromises their function (Fig 9, Table) (6-8). There are several theories of pathogenesis regarding the development of mediastinal fibrosis
from
Histoplasma
granulomas
(5,6).
One hypothesis is that rupture of the mediastinal granuloma occurs, releasing antigen, which results in reactive fibrosis. Another theory contends that lymphatic stasis and obstruction
lead
to the
transudation
of a pro-
teinaceous and cellular fluid, which incites the fibrotic process. Perhaps the most popular theory proposes that certain individuals have a hypersensitivity that predisposes them to fibrotic reaction as a result of the antigenic material present in caseous lymph nodes. There is no proved treatment for the inva-
Volume
11
Number
3
a. Figure
8. Case
4.
(a)
Posteroanterior
chest
b. radiograph
c. reveals
a subcarinal
mass
and a small
right-sided
pleural effusion. (b) Anteroposterior spot esophagogram reveals slight displacement of the esophagus to the left. The esophagus is also compressed at the level of the subcarinal mass, and there is splaying of the carina. (c) Lateral spot esophagogram obtained 4 months later shows the formation of a typical traction diverticulum.
Clinical Presentation Medlastinal Fibrosis Involved Anatomic Structures
Tracheobronchial
Superior
vena
of Histoplasma
Signs
tree
cava
Cough,
and Symptoms
dyspnea,
wheez-
ing, hemoptysis, recurrent pneumonia Superior vena caval syndrome
9. Gross specimen of mediastinal due to histoplasmosis. Medlastinal tissues cased by a fibrotic mass encircling vessels other structures.
Figure
sive and constrictive
mediastinitis.
process
.
1991
veins
Pulmonary Esophagus
arteries
Mitral stenosislike symptoms Cor pulmonale Dysphagia
are enand
of Histoplasma
Since the organisms of H capsulatum themselves are rarely found at the stage of fibrosing mediastinitis, antimicrobial therapy is of little benefit. Surgery may be necessary to release involved anatomic structures, but it also risks further spread of antigen and exacerbation of the fibrosing pro-
May
Pulmonary
cess. Fortunately, this has not been true in our patients, and there may be a difference in the nature of the fibrotic process in children versus that in adults (Wright PF, oral communication, 1991). Indeed, several of our children were found at operation to have a relatively soft collection of lymphoid tissue rather than a fibrotic mass compromising the adjacent structures.
Kirchner
et al
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a. Figure
b.
10. CaseS. (a) Frontal radiograph shows left hilar adenopathy stem bronchus, a finding confirmed on the chest tomogram (b)
and narrowing
of the left main
Figure
11. Case 6. (a) Posteroanterior chest radiograph shows the contracted volume of the right heand the narrowed right main stem bronchus. Also present are infiltrates in the right lung, a rightsided pleural effusion, and a subcarinal mass effect. (b) Frontal bronchogram demonstrates narrowing of the right main stem bronchus and bronchus intermedius and some splaying of the carmna. (Reprinted, with permission, from reference 6.) mithorax
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3
a.
b.
Figure 12. Case 7. chus. (b) Ti -weighted
.
Bronchial
When
the
(a)
Frontal chest radiograph coronal MR image better
reveals a subtle narrowing of the left main stem brondemonstrates narrowing of the left main stem bronchus.
Compromise
ted.
tracheobronchial
tree
He had
hin test
is involved
in the fibrotic process of histoplasmosis, the patient may have a variety of signs and symptoms, including cough, dyspnea, wheezing, hemoptysis, and recurrent pneumonia.
negative
and
results
positive
from
results
from
a tubercua histoplas-
mm test. The initial chest radiograph showed right pleural thickening and volume loss, and the bronchogram demonstrated narrowing of the right main stem bronchus (Fig 1 1) At pneumonectomy, the right hilum was encased in a mass of granulomatous scar .
Illustrative
Cases.-In
5 a 1 0-year-old
case
,
girl was admitted with a 4-month history of chest pain and low-grade fever unresponsive to treatment with ampicillin cm. Prior to admission, she
sistent nonproductive examination revealed and the initial chest
and erythromydeveloped a per-
cough. left-sided radiograph
Her physical wheezing, demonstrated left hilar adenopathy (Fig 1 Oa) The chest tomogram obtained after admission revealed compression and narrowing of the left main stem bronchus (Fig 1 Ob) Results of the tu.
.
berculin
test
the histoplasmin
were
negative,
but
test was
strongly
response
to
positive.
The patient was treated with triple sulfa antibiotics, and her symptoms gradually improved over subsequent months. In case 6, an 8-year-old boy with a 4-year history of poor weight gain, recurrent rightsided pneumonia, and hemoptysis was admit-
May
1991
tissue.
Pathologic
specimens
consisted
dense fibrous tissue enveloping pressing hilar structures. The granulomas present contained sulatum
organisms. 7, a 2-year-old of several episodes
In case history
perienced months.
left-sided Chest
girl
with a previous of pneumonia ex-
wheezing
radiography
of
and cornfew caseous sparse H cap-
for several revealed
narrow-
ing of the left main stem bronchus, approximately 1 cm distal to the carmna (Fig 1 2a). Coronal MR imaging showed a soft-tissue mass encasing the bronchus.
sis was suggested of a complement
and The
extrinsically diagnosis
compressing of histoplasmo-
due to the positive fixation test.
Kirchner
et al
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results
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373
Figure shows
13. Case 8. bilateral hilar
(a) Frontal chest radiograph and subcarmnal adenopathy
and the narrowed left main stem bronchus. ual barium from an upper gastrointestinal ries is present in the left upper scan also shows the subcarmnal
adenopathy with compression stem bronchus and bronchus
In case a 6-month
loss.
vealed
subcarmnal
athy
quadrant. (b) CT and bilateral hilar
of the left main intermedius.
8, a 16-year-old girl presented history of cough, chest pain,
weight with
Chest
radiography and
compression
and
bilateral
hilar
.
test were
spectively.
matous
polypoid
well as extrinsic rowed bronchi.
brosis,
negative
and
Bronchoscopy
but
endobronchial
no organisms,
.
Vascular
re-
found
as
narand
vena
cava,
c
fi-
subse-
by open biopsy. ketoconazole.
Compromise
superior
ies, and the compromised
lesions
were
stern
(Fig a histogranulo-
of the granulomas
quent to aspiration followed The patient was treated with
The
adenop-
positive,
revealed
compression Caseating
with and
CT re-
of the left main
bronchus and bronchus intermedius 1 3) Results of a tuberculin test and
plasmin
Residtract se-
b
ary to histoplasmosis. the
pulmonary veins by the fibrotic
pulmonary
arter-
can be severely process second-
volved,
the
those of mitral guarded. Illustrative
man and
374
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et al
symptoms
stenosis
and
Cases.-In
was
At age
When the latter are in-
patient’s
referred
22 years,
underwent
case
to our he had
chest
may
is
9, a 33-year-old
hospital cough
for surgery. and
radiography,
Volume
mimic
the prognosis
malaise
which
11
Number
3
a.
b. Figure 14. Case 9. (a) Ti-weighted MR image obtained at the level of the aortic arch shows an infiltrating mediastinal mass causing circumferential constriction of the superior vena cava (ar-
I
row)
.
(b) CT scan taken at a similar
level shows
calcification (arrowhead) in the region of the infiltrating mediastinal mass, consistent with fibros-
I
t4
A
ing mediastinitis
4 (a
secondary
to histoplasmosis.
Note the collateral vessels (arrows) in the soft tissues of the right chest wall. (c) Venogram obtained after injection of contrast material into the right subclavian vein demonstrates total occlusion
of the superior vessels
vena cava, with multiple
and flow
into
the azygous
vein
collateral (arrow).
C-
showed right-sided Eventually, results
paratracheal adenopathy. of a supraclavicular node
biopsy were interpreted as adenopathy due to histoplasmosis. Years later, he experienced generalized fatigue, facial swelling accompanied by a full feeling in his head and chest, and some difficulty swallowing. He was treated at another hospital with antico-
agulants
May
before
1991
being
referred
to our
tal for possible surgery. The findings from MR imaging, CT, and venography confirmed the
clinical
obstruction
diagnosis
(Fig
to undergo surgery out medications.
14).
of superior vena caval The patient chose not and was discharged with-
hospi-
Kirchner
Ct
al
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375
Figure the
15. cardiac
Case
10.
silhouette
in the right
(a)
Frontal
and
aortic
arch
on the
angle.
(b)
Pulmonary
cardiophrenic
lobe pulmonary
artery
and marked
In case
10, a 1 2-year-old pericarditis 6 months previously,
Histoplasma
nosed oped
a heart
chest
murmur,
radiograph
shows
left.
There
an anterior
mediastinal
is considerable
fibrosis
arteriogram
compromise
shows
of the vessels
mass, in the
complete
occlusion
to the left lower
which left
obliterates
upper
lobe
and
of the left upper
lobe.
girl, in whom had been diagrecently devel-
anorexia,
weight
loss,
cough, and exercise intolerance. Chest radiography showed a large, primarily left-sided mediastinal mass (Fig 1 5a) Pulmonary arteriography demonstrated compromise of the .
pulmonary arterial flow to the left lung (Fig 15b). In case 6, the 8-year-old boy with mediastinal fibrosis narrowing the right main stem bronchus (Fig 11) also had pulmonary artery compromise as a result of histoplasmosis (Fig 16). Figure onstrates
16. Case complete
6.
Pulmonary occlusion
nary artery and normal printed, with permission,
376
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et al
flow
arteriogram of the right
dempulmo-
to the left lung. (Refrom reference 6.)
Volume
11
Number
3
a.
b.
Figure 17. Case 11. mediastinal mass with are the
also calcifications esophagus by the
.
Esophageal
(a) Posteroanterior chest radiograph from a barium esophagographic study shows a calcification at the level of the aorticopulmonary window and the left hilum. There peripherally in the left lung. (b) A single spot esophagogram reveals constriction of mass.
Compromise
Severe
compression of the esophagus by mediastinal fibrosis can lead to swallowing dysfunction, but in some cases the involvement may be relatively asymptomatic. Histoplasma
Illustrative
Cases.-In
old girl was
admitted
case 11, a 13-yearto the emergency room
with symptoms of dysphagia. phy and a barium swallow performed body (Fig
May
1991
Chest radiograexamination were
to rule out an esophageal 17). A mediastinal mass
right pleural effusion agnosis of histoplasmosis
were
found,
was made
basis of clinical and radiologic In case 12, a 6-year-old boy
history results
and the dion the
findings. had a 6-month
of dry, hacking cough, with positive from a histoplasmin test and negative
results from phy revealed
subsequent esophagus
a tuberculin
test.
Chest
radiogra-
a large mediastinal mass, and esophagography showed the to be narrowed
by the mass
foreign and small
Kirchner
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b.
a.
FIgure
18. Case
12.
(a) Frontal
chest
radiograph
reveals
a large mediastinal
mass that obliterates
recess and extends superiorly and to the left into the aorticopulmonary left suprahilar area. The left main stem bronchus is severely compromised. (b) Barium shows concentric narrowing of the esophagus at the level of the mass. azygoesophageal
(Fig
1 8).
Histologic
examination
of the
the
window and esophagogram
the
tissue
specimen obtained at thoracotorny revealed caseating granulomas. Acid-fast and special stains were negative for H capsulatum. This case illustrates the difficulty in making a tissue or culture diagnosis of histoplasmosis. U PERICARDITIS When a child living
in an area
endemic
for
histoplasmosis develops enlargement heart in conjunction with pneumonia, monary
nodules,
plasma
pericarditis
or adenopathy,
should
of the pul-
Histo-
be considered
in
the differential diagnosis. These secondary findings are relatively uncommon in idiopathic or viral pericarditis (9) Although pericardial effusion is rarely seen in uncomplicated histoplasmosis, it is commonly seen when Histoplasma pericarditis is present. .
The
presence
confirmed
378
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of pericardial by means
U
effusion
must
of echocardiography.
Kirchner
et al
be A
Figure 19. Case 13. Posteroanterior chest radiograph shows massive cardiomegaly; the heart has a ‘ ‘water bottle’ ‘ shape, consistent with pericardial effusion. Bilateral infiltrates are present, as well as paratracheal adenopathy on the right and subcarinal adenopathy. (Reprinted, with permission, from reference 9.)
Volume
11
Number
3
b.
Figure lower
20. Case lobe
(a) Posteroanterior
infiltrate.
enopathy. month
14.
There later
A right-sided
is a small
shows
chest
paratracheal
pleural
effusion
a normal-sized
heart
cheal mass on the right is unchanged, is suggestive of adenopathy.
retrosternal fat pad, pericardial effusion, served on the chest
with
pericardial
(1 0)
antigen
Illustrative
girl was
The
pathoit adjato
(1 1).
Cases.-In
admitted
resolution
representing
.
case
with
fever,
1 3 a 6-year-old ,
chest
pain,
cough, and sore throat of 2 weeks duration and fatigue, dyspnea, and orthopnea of 1 week duration. Examination revealed a friction rub at the left upper sternal border. Chest radiography showed cardiomegaly, pulmonary infiltrates, and adenopathy (Fig 1 9) Echocardiography showed a moderateto-large pericardial effusion. Pericardiocentesis yielded 50 mL of bloody fluid, which .
was mine
positive silver
test and tive.
for yeast stain.
complement
forms
Results
with of the
fixation
methenahistoplasmin
test
were
shows
represents
an enlarged either
posi-
chest
of the infiltrate
adenopathy.
and
and
Fullness
blisters
Physical sounds
cardiac
an enlarged
on the left. (b) Posteroanterior
and
genesis of this condition is uncertain; could be due to direct extension from cent affected lymph nodes or a reaction
histoplasmin
mass
a radiographic sign of is uncommonly obradiographs of children
effusion
radiograph
and a left
vein
radiograph
pleural
or ad-
obtained
effusion.
The
on her
hands,
feet,
a pericardial
window
and
revealed
abdomen.
distant
friction
radiography nary infiltrate,
showed cardiomegaly, and a right-sided 20a) Echocardiography
1
paratra-
in the aorticopulmonary
examination with
silhouette
azygous
heart
rub.
Chest
pulmoparatracheal showed
a
mass (Fig large pericardial effusion without tamponade. Pericardiocentesis yielded 50 mL of .
bloody exudative fluid. All cultures were negative for bacterial and viral organisms and for H capsulatum. Results of a histoplasmin test were strongly positive. Serum immunodiffusion findings were also positive. Chest radiography performed 1 month later demonstrated partial resolution of the cardiopulmonary findings (Fig 20b).
In case pain,
to his local tis had
1 5, a 1 3-year-old
dyspnea, been
and
boy with
palpitations
hospital.
was
pericardi-
Histoplasma
diagnosed
1 year
chest admitted
before,
and
a
pericardial effusion was diagnosed at this admission. His condition deteriorated, and he was transferred to our pediatric center. Examination
revealed
fever,
tachycardia,
a pen-
In case 14, a 9-year-old girl was admitted with recent fatigue and dyspnea and a 1month history of fever, malaise, anorexia,
May
1991
Kirchner
et al
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Figure 21. Case 15. (a) radiograph shows massive
Posteroantenior cardiomegaly,
infiltrates,
effusions, and calcifinode. (b) Short-axis
bilateral
pleural
cations within an azygous parasternal echocardiogram effusion
shows
(arrows).
(c)
the pericardial
M-mode effusion
chest bibasilar
shows a pericardial echocardiogram (arrows).
a.
b.
cardial Chest megaly strated
C.
friction rub, and hepatomegaly. radiography showed massive cardio(Fig 2 la) penicardial
.
Echocardiography effusion (Fig
Findings from cardiac catheterization gested constrictive penicarditis, and diectomy
380
U
was
hesions
were
visceral
and
RadioGraphics
performed.
present parietal
U
Dense
between penicardial
Kirchner
et al
demon2 ic).
2 lb,
sugpenicar-
fibrous
ad-
the thickened layers.
Stains
and serologic tests yielded negative results. The patient had an uneventful recovery. In case 16, a 7-year-old girl was admitted to her local hospital with fever, chest pain, and
malaise.
Chest
radiography
sive cardiomegaly, pulmonary pleural effusions (Fig 22a). toplasmin test were positive.
showed
mas-
infiltrates, and Results of a hisNo other tests
were performed. Follow-up radiography performed 2 months later shows resolution of cardiomegaly, infiltrates, and pleural effusion, but adenopathy has developed (Fig 22b).
Volume
11
Number
3
a. b. Figure 22. Case 16. (a) Posteroantenior chest radiograph shows cardiomegaly, lateral lower lobe infiltrates, and small bilateral pleural effusions. (Reprinted, erence 9.) (b) Posteroantenior chest radiograph obtained 2 months later shows resolution of the infiltrates and effusions. Prominent left hilar and paratracheal
SUMMARY
U
Although
rare,
mediastinal
complications
histoplasmosis, which include formation, progressive fibrosis, ditis, can be seen in children. usually related to compression vital tree,
structures such the pulmonary
superior
vena
though
there
findings,
cava,
and
are few
the imaging
as the arteries
tracheobronchial and veins, the
the esophagus.
specific
Al-
4.
5.
6.
radiologic
modalities
illustrated
here can be useful in delineating the characten and extent of disease and in suggesting a possible diagnosis.
7.
Acknowledgments: tants Barbara Heilman,
8.
We thank editorial assisBA, Margie Scoggins, and Tom Ebers, BA; photographerJohn Bobbitt, BS; pediatric cardiologist Gordon Moreau, MD; pathologist Robert Collins, MD; and medical illustratorJoel Butts, BFA, and his colleagues for their
assistance
in the preparation
Wieder
REFERENCES Edwards LB, Acquaviva FA, Livesay VT, et a!. An atlas of sensitivity to tuberculin, PPD-B, and histoplasmin in the U.S., part 2. Am Rev RespirDis 1969; 99(suppl):12-16. 2. Schwarz J, Baum GL. The history of histoplasmosis, 1906 to 1956. N EnglJ Med 1957; 256:253-258. 3. Edwards PQ. Histoplasmin sensitivity patterns around the world. In: Agello L, Chick
May
1991
ML, eds. Histoplasmosis:
Fibrous
manifestation Radiology
medias-
of mediastinal 1 977; 125:305-
312.
Wieder 5, White 1) III, SalazarJ, Gold RE, Moinuddin M, Tonkin I. Pulmonary artery occlusion due to histop!asmosis. AJR 1982; 138:243-25 1. Kirchner SG, Heller RM, Sell SH, Altemeier
9.
WA III.
1 0.
.
EW, Furcolow
5, RabinowitzJG.
tinitis: a late histop!asmosis.
of this manuscript.
U
1
ceedings of the Second National Conference. Springfield, Ill: Thomas, 1971; 97102. Goodwin RA, Des Prez RM. Pathogenesis and clinical spectrum of histoplasmosis. South MedJ 1973; 66:13-25. LoydjE, Tillman BF, AtkinsonJB, Des Prez RM. Mediastinal fibrosis complicating histoplasmosis. Medicine 1 988; 67:295-310. Goodwin BA, Nickel!JA, Des Prez RM. Mediastina! fibrosis complicating healed primaIT histop!asmosis and tuberculosis. Mcdicine 1972; 51:227-246.
of
granuloma and pericarSymptoms are or invasion of
right middle lobe and biwith permission, from refa normal-sized heart, with adenopathy is seen.
1 1
.
The radiological
features
of histo-
plasma pericarditis. Pediatr Radio! 1978; 7:7-9. Sto!z JL, Borns P, Schwade J. The pediatric pericardium. Radiology 1 974; 112:159165. Picardi JL, Kauffman CA, Schwarz J, Holmes JC, PhairJP, Fowler NO. Pericarditis caused by Histoplasma capsulatum. Am J Cardiol 1976; 37:82-88.
pro-
Kirchner
et al
U
RadioGraphics
U
381
of Mediastinal
Sandra
G. Kirchner,
Marta
Hernanz-Schulman,
Sharon
M.
Stein,
PeterF.
Wright,
Richard
M.
MD
MD MD
Heller,
MD
can
present
Histoplasmosis masses
MD
of lymph
nodes,
a diagnostic invasive
dilemma
mediastinal
if unusually fibrosis,
large
or pericarditis
result from the infection. These rare, late sequelae are often first suspected from findings on chest radiographs obtained for unrelated reaSons. Organisms are not always evident at histologic analysis at this stage. Mediastinal granulomas consist of lobulated masses of enlarged lymph nodes with central caseation, a peripheral thin capsule, and, occasionally,
calcification.
The
mass
does
not
invade
or
compromise
adjacent anatomic structures. Mediastinal fibrosis invades and can Seriously compromise the function of the tracheobronchial tree, superior vena cava, pulmonary arteries and veins, and esophagus; its symptoms mimic those of many other disorders. Pericarditis is commonly accompanied by pericardial effusion, pneumonia, and adenopathy. Although the radiologic findings of these conditions are nonspecific, they can be used with the clinical findings to suggest a diagnosis. Complications of histoplasmosis should be included in the differential diagnosis for patients residing in areas endemic to Histoplasma capsulatum. U INTRODUCTION Histoplasmosis is usually
a self-limited
disease
that
rarely
requires
therapy
in chil-
other than the very young or immunocompromised patient. However, complications can occur and are usually related to enlarged lymph nodes, the healing process, or dissemination. When the mediastinum is involved, formation of large dren
Abbreviation: Index
PAS
terms:
diastinitis,
Children, 67.2053
RadloGraphics i
From
M.H.S., sity
the
January requests cpsNA
system, fibrosis,
and 1 161
revision
the 21st
Histoplasmosis,
67.2053 67.273
67.2053
#{149}
#{149} Pericarditis,
#{149} Lung,
infection,
67.2053
#{149} Me-
5 1.2053
1
of Radiology
R.M.H.), 1991;
respiratory
1 1 :365-38
Department Center,
24,
acid-Schiff
#{149} Mediastinum,
1991;
S.M.S.,
Medical
periodic
and
Radiological
Department Ave
requested
of Pediatrics,
Sciences, Section
S, Nashville,
TN 37232-2675.
February
12 and received
MCN
D-1 120,
Section
oflnfectious From February
the 27;
Diseases 1990
RSNA
accepted
of Pediatric
Radiology
(P.F.W.),
Vanderbilt
scientific February
assembly. 28.
Address
(S.G.K., UniverReceived reprint
to S.G.K. 1991
365
Figure 1. Distribution of histoplasmosis worldwide. For both the map of the United States and the world, the key indicates the percentage of reactions to a histoplasmm skin test. (Reprinted, with permission, from references 1 and 3.)
granulomas or, less sis can be present.
often,
progressive
fibro-
The
states (1). Katherine
Dodd
U PATHOGENESIS AND CLINICAL CHARACTERISTICS
this is not possible, serologic testing (cornplement fixation or serum immunodiffusion) may provide the diagnosis. In an endemic area, the histoplasmin test may be unreliable as an indicator of acute disease related to H
,
OF
HISTOPLASMOSIS
Histoplasmosis
is caused by Histoplasma a fungal organism that usually infects the individual by way of the respiratory tract. In the United States, histoplasmosis is most prevalent in the major river valcapsulatum,
U
and southern Tomkins and
authors present the radiologic specof mediastinal histoplasmosis seen in a population of children with histoplasmosis treated at a large referral center during a 20year period. The use of a variety of imaging modalities including conventional radiography, tomography, bronchography, arteriography, ultrasound (US), computed tomography (CT) and magnetic resonance (MR) imaging is illustrated. trum
366
leys of the central Indeed, Drs Edna
RadioGraphics
U
Kirchner
Ct
al
made
the
first
antemortem
diagnosis
of
histoplasmosis in Nashville, Tennessee, in 1 932 (2), when they identified the organism in the peripheral blood monocytes of one of their patients. Histoplasmosis is also prevalent in 60 other countries (Fig 1) (3). Today, the diagnosis is made on the basis of cultures of the organism from affected tissue or identification of the yeast forms stained Gomori
with periodic methenamine
acid-Schiff silver (Fig
(PAS) or 2) When .
capsulatum.
In most patients, histoplasmosis is asymptomatic, and the infection is self-limited;
Volume
11
Number
3
a. b. Figure 2. (a) Photomicrograph (original magnIfication, 1,000 X 2.5; cotton phenol blue stain) of mycehal form of H capsulatum In tissue culture shows tuberculated macroconidium. (b) Photomicrograph (original magnification, 400 X 2.5; PAS stain) of H capsulatum in bone marrow section shows intracellular yeast forms in macrophages.
Inhalation
of H Capsulatum
Spores
into Aveoli Symptomatic
Asymptornatic
I
Dissemination
Regional
lymphadenopathy Pneumonltis
Nonsegmental
_
/N Resolution
Histoplasmoma
Resolution nodes with or without calcification Residual
Mediastinal
granuloma
Mediastinal
fIbrosis
Figure 3. Diagram outcomes of primary
outlines the histoplasmo-
sis in children. obstruction vena cava and azygos vein superior
pulmonary and veinb
arteries
bronchi
esophagus
Pericarditis
when
symptoms
nonspecific malaise (4). companied
do occur,
and include The initial by hilar
they
or mediastinal
enopathy
and
ofwhich
can
be seen
on chest
These
findings
usually
resolve
weeks
to months.
May
1991
are
generally
fever, cough, and infection may be ac-
peripheral
lymphad-
pneumonitis,
Medlastinal
mediastinal fibrosis, and pericarditis are rare, late sequelae of mediastinal histoplasmosis. Possible outcomes of primary histoplasmosis in children are outlined in Figure 3.
both
radiographs.
over
several
granulorna,
Kirchner
et al
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367
Figure 4. Histologic section (original magnification, 10 X 2.5; hematoxylin-eosin stain) of a lymph node involved with H cap. sulatum shows the majority of the node to be effaced by caseous granulomas.
a.
b.
5. Case 1. Posteroanterior (a) and lateral (b) chest radiographs show upper lobe area from a prior biopsy. Bilateral hilar and mediastinal adenopathy diffuse, nodular pulmonary infiltrates. Figure
U MEDIASTINAL GRANULOMA Mediastinal granuloma is an uncommon complication of primary histoplasmosis that usually becomes clinically apparent at some time remote from the initial infection. In children, the granuloma is often identified on chest radiographs obtained for unrelated reasons. The involvement of adjacent struc-
tures
is minimal,
U
Kirchner
et al
minor
consists
of a
lobulated mass of lymph nodes several centimeters in thickness, surrounded by a thin capsule (5) Histologic examination of the involved nodes shows varying degrees of central caseation, and calcification will occa.
be present
cent anatomic compression,
#{149}RadioGraphics
sutures in the left associated with
few or only
symptoms are present (5). The mediastinal granuloma
sionally
368
and
surgical is seen,
(Fig
structures if present,
4).
Invasion
of adja-
is not present, is minor.
Volume
11
Number
and
3
b.
a
Figure 6. Case 2. (a) Posteroanterior radiograph of the chest reveals a large, primarily right-sided paratracheal mass that compromises the lumen of the trachea and the right and left main stem bronchi. (b) Contrast material-enhanced CT scans of the chest reveal a large mediastinal mass that involves the right paratracheal area, surrounds the right main stem bronchus, and extends approximately 3 cm below the carina. The mass is inhomogeneous in attenuation and contains small calcifications.
Illustrative Cases.-In case 1 a 3-year-old girl was admitted to the hospital with recurrent cough and fever related to histoplasmosis. She had been admitted to another hospital 1 2 months previously with fever of unknown origin. Thorough evaluation revealed no cause for the chest radiographic findings of hilar and mediastinal adenopathy and pulmonary infiltrate (Fig 5). Histologic examination of biopsy specimens from the mediastinal lymph nodes and lung showed multiple caseating granulomas; yeast forms were seen with special stains. Serologic testing was positive for histoplasmosis, and cultures were positive for H capsulatum. Treatment with ketoconazole was begun. The child had no symptoms at follow-up examination 8 months later, and the medication was discontinued. However, her chest radiograph showed no improvement. In case 2, a 3-year-old child with asthma ,
was
May
admitted
1991
to the hospital
because
diastinal mass noted on a chest radiograph taken because of congestion and fever (Fig 6a) CT scans revealed a large inhomogeneous mass, containing calcifications (Fig 6b). The diagnosis of histoplasmosis was made on .
the basis of calcification adenopathy, negative test,
positive
results
in the paratracheal results of a tuberculin of a histoplasmin
and immunodiffusion
studies
test,
positive
for
histoplasmosis. The youngster underwent surgical resection of the right paratracheal mass and received amphotericin B. No evidence of fungus could be found in the specimen of granulomatous tissue. Follow-up chest radiographs revealed a small residual paratracheal mass. The child fared well except
for
recurrent
asthmatic
attacks.
of a me-
Kirchner
et al
#{149}RadioGrapbics
U
369
a.
b.
Figure 7. Case 3. (a) Posteroanterior chest radiograph shows a large paratracheal mass on the right. No calcifications are seen within the mass. (b) Contrast-enhanced CT scans show a large right-sided paratracheal mass with minimal tracheal deviation and compression. No calcification is identified within the mass.
cheal
findings resolved entirely over a 2-month penod. An esophagogram obtained 4 months later showed the formation of a traction diverticulum (Fig 8c).
granuloma. No organisms were tissue cultures or in specimens
Although mediastinal fibrosis occurs less frequently than mediastinal granuloma, it is a much more severe complication of histoplasmosis (4) The fibrotic mass of tissue, rather than just compressing adjacent anatomic
In case 3, a 14-year-old patient was admitted to the pediatric surgical service with a history
of cough
and
a right-sided
paratra-
mass detected at chest radiography and CT (Fig 7). The likely diagnosis was thought to be histoplasmosis because of positive results from a histoplasmin test and negative results from a tuberculin test. Biopsy of the paratracheal mass revealed a fibrocaseous
methenamine stains. azole.
The
silver patient
nitrate was
and
treated
In case
identified stained
in with
acid-fast with
ketocon-
4, a 1 5-year-old patient was refever, pleuritic chest pain, and a subcarmnal mass detected on the initial chest radiograph (Fig 8a) A barium swallow study showed that the esophagus was displaced and compressed by the mass, and the tracheal bifurcation was also broadened (Fig 8b). Cultures of the pleural fluid were negative for H capsulatum. Results of the tuberculin test were also negative, while those of the histoplasmin test and complement fixation tests were positive. The chest radiographic ferred
for
.
370
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Kirchner
et al
U
MEDIASTINAL
FIBROSIS
.
structures,
gradually
invades
them
and
se-
verely compromises their function (Fig 9, Table) (6-8). There are several theories of pathogenesis regarding the development of mediastinal fibrosis
from
Histoplasma
granulomas
(5,6).
One hypothesis is that rupture of the mediastinal granuloma occurs, releasing antigen, which results in reactive fibrosis. Another theory contends that lymphatic stasis and obstruction
lead
to the
transudation
of a pro-
teinaceous and cellular fluid, which incites the fibrotic process. Perhaps the most popular theory proposes that certain individuals have a hypersensitivity that predisposes them to fibrotic reaction as a result of the antigenic material present in caseous lymph nodes. There is no proved treatment for the inva-
Volume
11
Number
3
a. Figure
8. Case
4.
(a)
Posteroanterior
chest
b. radiograph
c. reveals
a subcarinal
mass
and a small
right-sided
pleural effusion. (b) Anteroposterior spot esophagogram reveals slight displacement of the esophagus to the left. The esophagus is also compressed at the level of the subcarinal mass, and there is splaying of the carina. (c) Lateral spot esophagogram obtained 4 months later shows the formation of a typical traction diverticulum.
Clinical Presentation Medlastinal Fibrosis Involved Anatomic Structures
Tracheobronchial
Superior
vena
of Histoplasma
Signs
tree
cava
Cough,
and Symptoms
dyspnea,
wheez-
ing, hemoptysis, recurrent pneumonia Superior vena caval syndrome
9. Gross specimen of mediastinal due to histoplasmosis. Medlastinal tissues cased by a fibrotic mass encircling vessels other structures.
Figure
sive and constrictive
mediastinitis.
process
.
1991
veins
Pulmonary Esophagus
arteries
Mitral stenosislike symptoms Cor pulmonale Dysphagia
are enand
of Histoplasma
Since the organisms of H capsulatum themselves are rarely found at the stage of fibrosing mediastinitis, antimicrobial therapy is of little benefit. Surgery may be necessary to release involved anatomic structures, but it also risks further spread of antigen and exacerbation of the fibrosing pro-
May
Pulmonary
cess. Fortunately, this has not been true in our patients, and there may be a difference in the nature of the fibrotic process in children versus that in adults (Wright PF, oral communication, 1991). Indeed, several of our children were found at operation to have a relatively soft collection of lymphoid tissue rather than a fibrotic mass compromising the adjacent structures.
Kirchner
et al
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RadioGraphics
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371
a. Figure
b.
10. CaseS. (a) Frontal radiograph shows left hilar adenopathy stem bronchus, a finding confirmed on the chest tomogram (b)
and narrowing
of the left main
Figure
11. Case 6. (a) Posteroanterior chest radiograph shows the contracted volume of the right heand the narrowed right main stem bronchus. Also present are infiltrates in the right lung, a rightsided pleural effusion, and a subcarinal mass effect. (b) Frontal bronchogram demonstrates narrowing of the right main stem bronchus and bronchus intermedius and some splaying of the carmna. (Reprinted, with permission, from reference 6.) mithorax
372
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Volume
11
Number
3
a.
b.
Figure 12. Case 7. chus. (b) Ti -weighted
.
Bronchial
When
the
(a)
Frontal chest radiograph coronal MR image better
reveals a subtle narrowing of the left main stem brondemonstrates narrowing of the left main stem bronchus.
Compromise
ted.
tracheobronchial
tree
He had
hin test
is involved
in the fibrotic process of histoplasmosis, the patient may have a variety of signs and symptoms, including cough, dyspnea, wheezing, hemoptysis, and recurrent pneumonia.
negative
and
results
positive
from
results
from
a tubercua histoplas-
mm test. The initial chest radiograph showed right pleural thickening and volume loss, and the bronchogram demonstrated narrowing of the right main stem bronchus (Fig 1 1) At pneumonectomy, the right hilum was encased in a mass of granulomatous scar .
Illustrative
Cases.-In
5 a 1 0-year-old
case
,
girl was admitted with a 4-month history of chest pain and low-grade fever unresponsive to treatment with ampicillin cm. Prior to admission, she
sistent nonproductive examination revealed and the initial chest
and erythromydeveloped a per-
cough. left-sided radiograph
Her physical wheezing, demonstrated left hilar adenopathy (Fig 1 Oa) The chest tomogram obtained after admission revealed compression and narrowing of the left main stem bronchus (Fig 1 Ob) Results of the tu.
.
berculin
test
the histoplasmin
were
negative,
but
test was
strongly
response
to
positive.
The patient was treated with triple sulfa antibiotics, and her symptoms gradually improved over subsequent months. In case 6, an 8-year-old boy with a 4-year history of poor weight gain, recurrent rightsided pneumonia, and hemoptysis was admit-
May
1991
tissue.
Pathologic
specimens
consisted
dense fibrous tissue enveloping pressing hilar structures. The granulomas present contained sulatum
organisms. 7, a 2-year-old of several episodes
In case history
perienced months.
left-sided Chest
girl
with a previous of pneumonia ex-
wheezing
radiography
of
and cornfew caseous sparse H cap-
for several revealed
narrow-
ing of the left main stem bronchus, approximately 1 cm distal to the carmna (Fig 1 2a). Coronal MR imaging showed a soft-tissue mass encasing the bronchus.
sis was suggested of a complement
and The
extrinsically diagnosis
compressing of histoplasmo-
due to the positive fixation test.
Kirchner
et al
U
results
RadioGraphics
U
373
Figure shows
13. Case 8. bilateral hilar
(a) Frontal chest radiograph and subcarmnal adenopathy
and the narrowed left main stem bronchus. ual barium from an upper gastrointestinal ries is present in the left upper scan also shows the subcarmnal
adenopathy with compression stem bronchus and bronchus
In case a 6-month
loss.
vealed
subcarmnal
athy
quadrant. (b) CT and bilateral hilar
of the left main intermedius.
8, a 16-year-old girl presented history of cough, chest pain,
weight with
Chest
radiography and
compression
and
bilateral
hilar
.
test were
spectively.
matous
polypoid
well as extrinsic rowed bronchi.
brosis,
negative
and
Bronchoscopy
but
endobronchial
no organisms,
.
Vascular
re-
found
as
narand
vena
cava,
c
fi-
subse-
by open biopsy. ketoconazole.
Compromise
superior
ies, and the compromised
lesions
were
stern
(Fig a histogranulo-
of the granulomas
quent to aspiration followed The patient was treated with
The
adenop-
positive,
revealed
compression Caseating
with and
CT re-
of the left main
bronchus and bronchus intermedius 1 3) Results of a tuberculin test and
plasmin
Residtract se-
b
ary to histoplasmosis. the
pulmonary veins by the fibrotic
pulmonary
arter-
can be severely process second-
volved,
the
those of mitral guarded. Illustrative
man and
374
U
RadioGraphics
U
Kirchner
et al
symptoms
stenosis
and
Cases.-In
was
At age
When the latter are in-
patient’s
referred
22 years,
underwent
case
to our he had
chest
may
is
9, a 33-year-old
hospital cough
for surgery. and
radiography,
Volume
mimic
the prognosis
malaise
which
11
Number
3
a.
b. Figure 14. Case 9. (a) Ti-weighted MR image obtained at the level of the aortic arch shows an infiltrating mediastinal mass causing circumferential constriction of the superior vena cava (ar-
I
row)
.
(b) CT scan taken at a similar
level shows
calcification (arrowhead) in the region of the infiltrating mediastinal mass, consistent with fibros-
I
t4
A
ing mediastinitis
4 (a
secondary
to histoplasmosis.
Note the collateral vessels (arrows) in the soft tissues of the right chest wall. (c) Venogram obtained after injection of contrast material into the right subclavian vein demonstrates total occlusion
of the superior vessels
vena cava, with multiple
and flow
into
the azygous
vein
collateral (arrow).
C-
showed right-sided Eventually, results
paratracheal adenopathy. of a supraclavicular node
biopsy were interpreted as adenopathy due to histoplasmosis. Years later, he experienced generalized fatigue, facial swelling accompanied by a full feeling in his head and chest, and some difficulty swallowing. He was treated at another hospital with antico-
agulants
May
before
1991
being
referred
to our
tal for possible surgery. The findings from MR imaging, CT, and venography confirmed the
clinical
obstruction
diagnosis
(Fig
to undergo surgery out medications.
14).
of superior vena caval The patient chose not and was discharged with-
hospi-
Kirchner
Ct
al
U
RadioGraphics
U
375
Figure the
15. cardiac
Case
10.
silhouette
in the right
(a)
Frontal
and
aortic
arch
on the
angle.
(b)
Pulmonary
cardiophrenic
lobe pulmonary
artery
and marked
In case
10, a 1 2-year-old pericarditis 6 months previously,
Histoplasma
nosed oped
a heart
chest
murmur,
radiograph
shows
left.
There
an anterior
mediastinal
is considerable
fibrosis
arteriogram
compromise
shows
of the vessels
mass, in the
complete
occlusion
to the left lower
which left
obliterates
upper
lobe
and
of the left upper
lobe.
girl, in whom had been diagrecently devel-
anorexia,
weight
loss,
cough, and exercise intolerance. Chest radiography showed a large, primarily left-sided mediastinal mass (Fig 1 5a) Pulmonary arteriography demonstrated compromise of the .
pulmonary arterial flow to the left lung (Fig 15b). In case 6, the 8-year-old boy with mediastinal fibrosis narrowing the right main stem bronchus (Fig 11) also had pulmonary artery compromise as a result of histoplasmosis (Fig 16). Figure onstrates
16. Case complete
6.
Pulmonary occlusion
nary artery and normal printed, with permission,
376
U
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Kirchner
et al
flow
arteriogram of the right
dempulmo-
to the left lung. (Refrom reference 6.)
Volume
11
Number
3
a.
b.
Figure 17. Case 11. mediastinal mass with are the
also calcifications esophagus by the
.
Esophageal
(a) Posteroanterior chest radiograph from a barium esophagographic study shows a calcification at the level of the aorticopulmonary window and the left hilum. There peripherally in the left lung. (b) A single spot esophagogram reveals constriction of mass.
Compromise
Severe
compression of the esophagus by mediastinal fibrosis can lead to swallowing dysfunction, but in some cases the involvement may be relatively asymptomatic. Histoplasma
Illustrative
Cases.-In
old girl was
admitted
case 11, a 13-yearto the emergency room
with symptoms of dysphagia. phy and a barium swallow performed body (Fig
May
1991
Chest radiograexamination were
to rule out an esophageal 17). A mediastinal mass
right pleural effusion agnosis of histoplasmosis
were
found,
was made
basis of clinical and radiologic In case 12, a 6-year-old boy
history results
and the dion the
findings. had a 6-month
of dry, hacking cough, with positive from a histoplasmin test and negative
results from phy revealed
subsequent esophagus
a tuberculin
test.
Chest
radiogra-
a large mediastinal mass, and esophagography showed the to be narrowed
by the mass
foreign and small
Kirchner
et al
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377
b.
a.
FIgure
18. Case
12.
(a) Frontal
chest
radiograph
reveals
a large mediastinal
mass that obliterates
recess and extends superiorly and to the left into the aorticopulmonary left suprahilar area. The left main stem bronchus is severely compromised. (b) Barium shows concentric narrowing of the esophagus at the level of the mass. azygoesophageal
(Fig
1 8).
Histologic
examination
of the
the
window and esophagogram
the
tissue
specimen obtained at thoracotorny revealed caseating granulomas. Acid-fast and special stains were negative for H capsulatum. This case illustrates the difficulty in making a tissue or culture diagnosis of histoplasmosis. U PERICARDITIS When a child living
in an area
endemic
for
histoplasmosis develops enlargement heart in conjunction with pneumonia, monary
nodules,
plasma
pericarditis
or adenopathy,
should
of the pul-
Histo-
be considered
in
the differential diagnosis. These secondary findings are relatively uncommon in idiopathic or viral pericarditis (9) Although pericardial effusion is rarely seen in uncomplicated histoplasmosis, it is commonly seen when Histoplasma pericarditis is present. .
The
presence
confirmed
378
U
RadioGrapbks
of pericardial by means
U
effusion
must
of echocardiography.
Kirchner
et al
be A
Figure 19. Case 13. Posteroanterior chest radiograph shows massive cardiomegaly; the heart has a ‘ ‘water bottle’ ‘ shape, consistent with pericardial effusion. Bilateral infiltrates are present, as well as paratracheal adenopathy on the right and subcarinal adenopathy. (Reprinted, with permission, from reference 9.)
Volume
11
Number
3
b.
Figure lower
20. Case lobe
(a) Posteroanterior
infiltrate.
enopathy. month
14.
There later
A right-sided
is a small
shows
chest
paratracheal
pleural
effusion
a normal-sized
heart
cheal mass on the right is unchanged, is suggestive of adenopathy.
retrosternal fat pad, pericardial effusion, served on the chest
with
pericardial
(1 0)
antigen
Illustrative
girl was
The
pathoit adjato
(1 1).
Cases.-In
admitted
resolution
representing
.
case
with
fever,
1 3 a 6-year-old ,
chest
pain,
cough, and sore throat of 2 weeks duration and fatigue, dyspnea, and orthopnea of 1 week duration. Examination revealed a friction rub at the left upper sternal border. Chest radiography showed cardiomegaly, pulmonary infiltrates, and adenopathy (Fig 1 9) Echocardiography showed a moderateto-large pericardial effusion. Pericardiocentesis yielded 50 mL of bloody fluid, which .
was mine
positive silver
test and tive.
for yeast stain.
complement
forms
Results
with of the
fixation
methenahistoplasmin
test
were
shows
represents
an enlarged either
posi-
chest
of the infiltrate
adenopathy.
and
and
Fullness
blisters
Physical sounds
cardiac
an enlarged
on the left. (b) Posteroanterior
and
genesis of this condition is uncertain; could be due to direct extension from cent affected lymph nodes or a reaction
histoplasmin
mass
a radiographic sign of is uncommonly obradiographs of children
effusion
radiograph
and a left
vein
radiograph
pleural
or ad-
obtained
effusion.
The
on her
hands,
feet,
a pericardial
window
and
revealed
abdomen.
distant
friction
radiography nary infiltrate,
showed cardiomegaly, and a right-sided 20a) Echocardiography
1
paratra-
in the aorticopulmonary
examination with
silhouette
azygous
heart
rub.
Chest
pulmoparatracheal showed
a
mass (Fig large pericardial effusion without tamponade. Pericardiocentesis yielded 50 mL of .
bloody exudative fluid. All cultures were negative for bacterial and viral organisms and for H capsulatum. Results of a histoplasmin test were strongly positive. Serum immunodiffusion findings were also positive. Chest radiography performed 1 month later demonstrated partial resolution of the cardiopulmonary findings (Fig 20b).
In case pain,
to his local tis had
1 5, a 1 3-year-old
dyspnea, been
and
boy with
palpitations
hospital.
was
pericardi-
Histoplasma
diagnosed
1 year
chest admitted
before,
and
a
pericardial effusion was diagnosed at this admission. His condition deteriorated, and he was transferred to our pediatric center. Examination
revealed
fever,
tachycardia,
a pen-
In case 14, a 9-year-old girl was admitted with recent fatigue and dyspnea and a 1month history of fever, malaise, anorexia,
May
1991
Kirchner
et al
U
RadioGraphics
U
379
Figure 21. Case 15. (a) radiograph shows massive
Posteroantenior cardiomegaly,
infiltrates,
effusions, and calcifinode. (b) Short-axis
bilateral
pleural
cations within an azygous parasternal echocardiogram effusion
shows
(arrows).
(c)
the pericardial
M-mode effusion
chest bibasilar
shows a pericardial echocardiogram (arrows).
a.
b.
cardial Chest megaly strated
C.
friction rub, and hepatomegaly. radiography showed massive cardio(Fig 2 la) penicardial
.
Echocardiography effusion (Fig
Findings from cardiac catheterization gested constrictive penicarditis, and diectomy
380
U
was
hesions
were
visceral
and
RadioGraphics
performed.
present parietal
U
Dense
between penicardial
Kirchner
et al
demon2 ic).
2 lb,
sugpenicar-
fibrous
ad-
the thickened layers.
Stains
and serologic tests yielded negative results. The patient had an uneventful recovery. In case 16, a 7-year-old girl was admitted to her local hospital with fever, chest pain, and
malaise.
Chest
radiography
sive cardiomegaly, pulmonary pleural effusions (Fig 22a). toplasmin test were positive.
showed
mas-
infiltrates, and Results of a hisNo other tests
were performed. Follow-up radiography performed 2 months later shows resolution of cardiomegaly, infiltrates, and pleural effusion, but adenopathy has developed (Fig 22b).
Volume
11
Number
3
a. b. Figure 22. Case 16. (a) Posteroantenior chest radiograph shows cardiomegaly, lateral lower lobe infiltrates, and small bilateral pleural effusions. (Reprinted, erence 9.) (b) Posteroantenior chest radiograph obtained 2 months later shows resolution of the infiltrates and effusions. Prominent left hilar and paratracheal
SUMMARY
U
Although
rare,
mediastinal
complications
histoplasmosis, which include formation, progressive fibrosis, ditis, can be seen in children. usually related to compression vital tree,
structures such the pulmonary
superior
vena
though
there
findings,
cava,
and
are few
the imaging
as the arteries
tracheobronchial and veins, the
the esophagus.
specific
Al-
4.
5.
6.
radiologic
modalities
illustrated
here can be useful in delineating the characten and extent of disease and in suggesting a possible diagnosis.
7.
Acknowledgments: tants Barbara Heilman,
8.
We thank editorial assisBA, Margie Scoggins, and Tom Ebers, BA; photographerJohn Bobbitt, BS; pediatric cardiologist Gordon Moreau, MD; pathologist Robert Collins, MD; and medical illustratorJoel Butts, BFA, and his colleagues for their
assistance
in the preparation
Wieder
REFERENCES Edwards LB, Acquaviva FA, Livesay VT, et a!. An atlas of sensitivity to tuberculin, PPD-B, and histoplasmin in the U.S., part 2. Am Rev RespirDis 1969; 99(suppl):12-16. 2. Schwarz J, Baum GL. The history of histoplasmosis, 1906 to 1956. N EnglJ Med 1957; 256:253-258. 3. Edwards PQ. Histoplasmin sensitivity patterns around the world. In: Agello L, Chick
May
1991
ML, eds. Histoplasmosis:
Fibrous
manifestation Radiology
medias-
of mediastinal 1 977; 125:305-
312.
Wieder 5, White 1) III, SalazarJ, Gold RE, Moinuddin M, Tonkin I. Pulmonary artery occlusion due to histop!asmosis. AJR 1982; 138:243-25 1. Kirchner SG, Heller RM, Sell SH, Altemeier
9.
WA III.
1 0.
.
EW, Furcolow
5, RabinowitzJG.
tinitis: a late histop!asmosis.
of this manuscript.
U
1
ceedings of the Second National Conference. Springfield, Ill: Thomas, 1971; 97102. Goodwin RA, Des Prez RM. Pathogenesis and clinical spectrum of histoplasmosis. South MedJ 1973; 66:13-25. LoydjE, Tillman BF, AtkinsonJB, Des Prez RM. Mediastinal fibrosis complicating histoplasmosis. Medicine 1 988; 67:295-310. Goodwin BA, Nickel!JA, Des Prez RM. Mediastina! fibrosis complicating healed primaIT histop!asmosis and tuberculosis. Mcdicine 1972; 51:227-246.
of
granuloma and pericarSymptoms are or invasion of
right middle lobe and biwith permission, from refa normal-sized heart, with adenopathy is seen.
1 1
.
The radiological
features
of histo-
plasma pericarditis. Pediatr Radio! 1978; 7:7-9. Sto!z JL, Borns P, Schwade J. The pediatric pericardium. Radiology 1 974; 112:159165. Picardi JL, Kauffman CA, Schwarz J, Holmes JC, PhairJP, Fowler NO. Pericarditis caused by Histoplasma capsulatum. Am J Cardiol 1976; 37:82-88.
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et al
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