i 288
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,‘
General David
Diagnosis
J. Eschelrnan,1
Case 1: Aneurysm
Ellen
Panageas,
Case of the Day Max
P. Rosen,
Laura
of the Ductus Arteriosus
fewer
than
25 cases
, All
authors:
is a short
reported
Department
AJR 156:1288-1294,
June
tubular
of Radiology,
in the literature.
Boston
University 566-1
John
F. O’Connor
The
,
ductus
Medical
Center,
288 © American
the
,
connection
1991 0361 -803X/91/1
and
allows exposure to the high systemic pressure aorta with subsequent dilatation and aneurysm formation [3, 4]. Some note that many adults with ductus arteriosus aneurysms are hypertensive [5, 6]. Clinically, most signs are related to mass effects. Dyspnea, cough, and transient or persistent dysphonia due to compression of the left recurrent laryngeal nerve are the most common [i 7]. However, in a review of 21 cases, an abnormal chest radiograph was the most common reason for further investigation [5]. Complications such as rupture, dissection, distal embolization, and hemorrhage from fistulous connection to the esophagus or bronchus have been described [1 7]. The average diameter is 5 cm, with one aneurysm as large as 8 x i 1 cm reported [5]. On chest radiographs, the ductus arteriosus aneurysm may be perceived as a change in the contour of the aortic arch or aortopulmonary window. Although adenopathy, neoplasms, or aneurysms related to the aorta itself are certainly more common masses at this site, Danza et al. [7] suggest two radiographic features indicative of a ductus arteriosus aneurysm. These signs are parietal calcification at the periphery of the lesion and/or mottled calcification at the aortic side of the mass in addition to a small pedicle linking the lesion to the pulmonary artery. This pedicle may be obscured with large aneurysms. CT will show the relationship of the aneurysm to within
between the left pulmonary artery and aorta. A remnant of the left sixth aortic arch, it normally undergoes physiologic closure soon after birth, but complete anatomic obliteration requires up to 12 weeks. Aneurysms within the ductus arteriosus usually result from incomplete closure. In the few reports of aneurysms involving a patent ductus arteriosus in adults, it is uncertain whether the ductus arteriosus recanalized or original patency persisted [i]. Normal closure of the ductus arteriosus begins before birth and proceeds from the pulmonary artery to the aortic end. Through a complex process of intimal thickening, endothelial invagination, smooth-muscle cell migration, and hyaluronic acid production, closure of this muscular artery is achieved [2]. When closure is incomplete, the pulmonary side closes and the aortic side remains patent. This may result from increased amounts of elastic tissue within the ductus arteriosus. Therefore, the ductus arteriosus resembles an elastic artery such as the aorta rather than a muscular artery [3}. In addition, low levels of hyaluronic acid have been associated with faulty closure [2]. Patency of the aortic side of the ductus arteriosus
Romo,
arteriosus
A large mediastinal mass was discovered on the chest radiograph (Figs. iA and i B) of a 73-year-old man with wellcontrolled hypertension. Several faint, curvilinear calcifications were noted in the lateral margin of the mass. The superior border of the mass appeared to abut the aorta. Chest CT (Figs. 1 C and 1 D) showed that the enhancing mass originated from the inferior aspect of the aortic arch and extended inferiorly, adjacent to the ascending aorta, to the level of the main pulmonary artery. Aortography (Figs. 1 E and i F) was performed 6 months later after chest radiographs (not shown) revealed enlargement of the mass. Aortography showed the i -cm neck of the aneurysm arising from the inferior surface of this tortuous atherosclerotic aorta, just distal to the left subclavian artery. The remainder of the aneurysm did not opacify because of thrombosis that had occurred since the CT scan was obtained. The patient underwent resection of the 8 x 6 x 6 cm aneurysm of the ductus arteriosus, and the aorta was repaired with a Dacron patch graft. Aneurysm of the ductus arteriosus is a rare entity in adults, with
Vitale
the aortic
and
pulmonary
artery,
while
possibly
revealing
,
88 E. Newton
Roentgen
arch
calcifications not detected by plain radiographs. The diameter of the lesion and presence of mural thrombus also will be identified. Angiography is highly specific, showing the neck of the aneurysm just distal to the origin of the left subclavian artery [1 4, 7]. Unlike true aneurysms of the aortic arch or false aneurysms resulting from trauma or prior aortic dissection, ductus arteriosus aneurysms are saccular, have a narrowed neck at the aortic orifice, and lack severe atheromatous change [5]. Although rare, ductus arteriosus aneurysms require consideration in the differential diagnosis of mediastinal masses because they have a 60% fatality rate due to complications. Criteria for resection include lesions greater than 3 cm in diameter, symptomatic aneurysms, and any that show progressive enlargement. It has been suggested that enlargement is not a finite process; therefore, any ductus arteriosus
St.
Ray Society
, Boston,
MA 021 1 8. Address
reprint
requests
to J. F. O’Connor.
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A
Fig. 1.-Case arteriosus.
1: Aneurysm
of ductus
A and B, Posteroanterior (A) and lateral (B) chest radiographs show a mediastinal mass in aortopulmonary win-
dow, which appears
to abut aorta on
lateral radiograph. Several thin, curvilinear calcifications are seen in lateral border of this mass. C and D, Axial CT scans at level of aortic arch (C, unenhanced) and carina (D, enhanced). Neck of aneurysm
arises arch.
from inferior Enhancing
aspect
of aortic
8 x 6 x 6 cm aneurysm
extends inferiorly, adjacent to ascending aorta,
to level
of main
pulmonary
artery. E and F, Subtracted left anterior oblique(E) and anteroposterior(F) projections from aortogram show 1-cm neck of aneurysm arising from inferior aspect of aortic arch, just distal to origin of left subclavian artery. This examination was performed 6 months after CT scanning, during which time
thrombus formed within aneurysm. A large soft-tissue mass corresponding to aneurysm is seen on anteroposterior projection lateral to neck of aneurysm in aortopulmonary window. Remainder of aorta is tortuous and atherosclerotic with ulcerating plaque.
‘
i 290
aneurysms, moved[i,
ESCHELMAN
regardless
of size
or symptoms,
should
be re-
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REFERENCES PD, Wojtowycz
MM, Karwande
SV, et al. Roentgenologic
CPC:
enlarging mediastinal mass. Invest Radiol 1987;22:240-243 2. DeReeder EG, Girard N, Poelmann RE, Van Munsteren JC, Patterson DF, Gittenberger-De Greet AC. Hyaluronic acid accumulation and endothelial cell detachment in intimal thickening of the vessel wall: the normal and genetically defective ductus arteriosus. Am J Pathol 1988;132:574-585 3, Gittenberger-De Greet AC. Persistent ductus arteriosus: most probably a primary congenital malformation. Br Heart J 1977;39:610-618
4. Cohen BA, Efremidis SC, Dan SJ, Robinson B, Rabinowitz
6. Borow KM, Hessel SJ, Sloss LI. Fistulous aneurysm of ductus arteriosus. Br Heart J 1981;45:467-470
7. Danza FM, Fusco A, Breda M, Bock aneurysm
The initial
appearance
of breast carcinoma as dense intrais exceptionally rare. However, Bruwer et al. [1 ] have described this appearance of punctate intranodal densities in patients receiving intramuscular gold injections for rheumatoid arthritis. Gold therapy may be very effective for active rheumatoid arthritis, possibly delaying or preventing the progression of erosions in some patients [2]. Although approximately half of the injected gold is eliminated via urine and stool, the rest remains in the body, often for years after therapy is stopped. Organs retaining the highest concentrations of injected gold are lymph nodes, adrenal glands, liver, kidneys, bone marrow, and spleen [i]. David J. Eschelman
JG. Aneurysm
of the ducts arteriosus in an adult. J Comput Assist Tomogr 1981;5: 421-423 5. Mitchell RS, Seifert FC, Miller DC, Jamieson SW, Shumway NE. Aneurysm of the diverticulum of the ductus arteriosus in the adult: successful surgical treatment in five patients and review of the literature. J Thorac Cardiovasc Surg 1983;86:400-408
arteriosus
AJR:156, June 1991
nodal microcalcifications
5]. Laura Vitale Romo David J. Eschelman
1 . Traughber
ET AL.
in an adult.
AiR
E, Lemmo G, Colavita 1984;143: 131-133
N. Ductus
REFERENCES 1 . Bruwer A, Nelson GW, Spark RP. Punctate simulating microcalcifications on mammograms.
87-88 2. Abramowicz 1989;31
M, ed. Drugs for rheumatoid
in Woman
with
A 45-year-old woman with a long history of chrysotherapy for rheumatoid arthritis had screening mammography. Routine mediolateral oblique views (Figs. 2A and 2B) revealed innumerable punctate densities in several axillary lymph nodes on both sides. A magnificaton view (Fig. 2C) showed the fine, intranodal, linear and punctate densities.
arthritis. Med Left Drugs
Ther
:61-64
Case 3: Giant-Cell Case 2: Intranodal Gold Deposits Rheumatoid Arthritis
intranodal gold deposits Radiology 1987;1 63:
Tumor of the Temporal
Bone
A 25-year-old man came to the emergency department with swelling on the right side of his head that had progressed for several months. He denied any history of trauma. A lateral skull radiograph (Fig. 3A) showed an expansile, lytic lesion involving the temporal bone. An unenhanced CT scan of the head at soft-tissue window settings showed that the central portion of the lesion contained heterogeneous soft tissue and calcifications (Fig. 3B). Images filmed at bone
GENERAL
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AJR:156, June 1991
Fig. 3.-Case
3: Giant-cell
tumor of the temporal
DIAGNOSIS
CASE
OF
THE
1291
DAY
bone.
A, Lateral skull radiograph shows an expansile, lytic lesion involving temporal bone. B, Axial unenhanced CT scan of head obtained with soft-tissue window sethngs shows that center of lesion contains heterogeneous soft tissue and calcifications. C, Axial unenhanced CT scan of head obtained with bone windows shows that lesion has greatly expanded diploic space. Lesion extends into anterior portion of petrous bone. D, Axial Ti-weighted (500/15) MR image of head after IV administration of gadopentetate dimeglumine shows lesion is composed of two distinct tissues. When compared with unenhanced Ti-weighted image (E), medial portion enhances, consistent with a solid component. Outer portion, which contains septa but does not enhance, is suggestive of a cystic component. E, Coronal Ti-weighted (560/15) unenhanced MR image of head shows encroachment of diploic space at base of skull, compression of temporal lobe, and distortion of middle cranial fossa. F, Axial T2-weighted (3000/90) MR image of head shows bright signal from outer aspect of lesion, which confirms presence of a lateral cystic component. Signal from inner portion of lesion is dark, consistent with a solid component.
windows
diploic
showed
that
a solid
and that
the
lesion
had
greatly
expanded
the
extended into the anterior portion of the petrous bone (Fig. 3C). MR images of the head were then obtained. After IV administration of gadopentetate dimeglumine, Ti-weighted (500/1 5) axial MR images showed that the lesion was composed of two distinct tissues (Fig. 3D). When compared with unenhanced Ti -weighted images (Fig. 3E), the medial portion enhanced, which was consistent with
space
component.
the lesion
The
septa but did not enhance, ponent. Axial T2-weighted
lateral
portion,
was suggestive (3000/90) MR
which
contained
of a cystic cornimages (Fig. 3F)
showed which
bright
signal
from
the
presence
confirmed
the
outer
The signal from the inner portion consistent with a solid component. Giant-cell
occur 6O%) may The ologic
tumors
classically
involve
especially
giant-cell
radiation
component.
lesion
long
was
tubular
dark, bones,
and have a high (40Malignant degeneration therapy
granuloma,
has been described appearance. This entity
entity,
radiologic
after
reparative
of the lesion,
cystic
of the
in the third to fourth decades, recurrence rate after resection. occur,
aspect
of a lateral
a separate
clinicopath-
and may have an identical is a reactive granulomatous
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1292
ESCHELMAN
process in response to intraosseous hemorrhage or inflammation. Often a history of trauma can be elicited. This lesion most commonly involves the mandible and maxilla and occurs in the first and second decades. The course is always benign. Curettage is usually the only treatment needed. Recurrence is extremely rare [1 2]. Both giant-cell tumors and giant-cell reparative granulomas have been reported in the temporal bone. Pathologic differentiation between these two entities is often very difficult and depends on the local distribution and shape of the giant cells, the presence or absence of hemosiderin and osteoid, and the shape of the stromal fibroblasts [2]. By 1 974 there had been 23 reported cases of giant-cell tumor of the temporal bone. In 1 974 all cases were reviewed, and I 8 of the 23 cases were reclassified as giant-cell reparative granulomas [2]. Between 1980 and 1 990, several published cases of similar lesions [3-9] have been reported as giant-cell tumors. Max P. Rosen ,
REFERENCES 1 . Resnick D, Kyriakos M, Gleenway GD. In: Resnick D, Naiwayama G, eds. Diagnosis of bone and joint disorders, 2nd ed. Philadelphia: Saunders, 1988:3757-3776 2. Hirschl 5, Katz A. Giant cell reparative granuloma outside the jaw bone. Hum Pathol i975;5:171-181 3, Cook HF, Miller R, Yamada A. Giant cell tumor of the infratemporal fossa: report of case. J Oral Maxiiofac Surg 1986;44: 651-656 4. Wilbur AC, Choi KH, Tan WS, Jafar JJ, Spigos DG. Giant cell tumor of the sphenoid bone mimicking a pituitary tumor. AJNR 1986;7:361-362 5. KiwitJCW, Schober R, Nicola N, Schirmer M, Wechsler W. Osteoclastomas of the petrous bone. Surg Neurol i986;26:59-62 6. Carmody RF, Rickles DJ, Johnson SF. Giant cell tumor of the sphenoid bone. J Comput Assist Tomogr 1983;7 :370-373 7. Tandon DA, Deka AC, Chaudhary C. Misra NK. Giant cell tumor of the temporosphenoidal region. J Laryngo/ Otol i988;102:449-451 8. Findlay JM, Chiasson D, Hudson AR, Chuli M. Giant cell tumor of the middle cranial fossa. J Neurosurg 1987;66:924-928 9. Henderson BTH, Whitwell H. Giant cell tumor of the skull: case report. Neurosurgery i988;23: 120-1 22
Case 4: Primary
Retropentoneal
Teratoma
This previously healthy 25-year-old woman had persistent lower back pain for 2 months after a motor vehicle accident. MR images (Figs. 4A and 4B) showed a right-sided retroperitoneal mass with signal intensities corresponding to fat, calcium, and soft-tissue components. The sonographic study (Figs. 4C and 4D) showed a solid suprarenal tumor containing a hyperechoic region consistent with fat and a heterogeneous region with focal calcifications. To better evaluate these tissue elements, CT was performed (Fig. 4E), verifying the large adipose component as well as the calcified and soft-tissue areas in this well-encapsulated tumor. At surgery, the right adrenal gland was found to be normal and the retroperitoneal mass was completely resected. Pathologic examination of the specimen revealed a mature retroperitoneal teratoma (Fig. 4F). Primary retroperitoneal teratornas are rare, representing 51 0% of primary retroperitoneal tumors [1 ]. The mean age of
ET
AL.
AJR:156,
June
1991
patients ranges between 1 3 and 16 years, with cases reported in a fetus and in patients up to 82 years old [2-4]. Fewer than 1 0-20% occur after the age of 30 years, with 43-55% diagnosed in the first decade of life [4]. Most authors have reported a higher prevalence among females. Teratomas derive from germ cells that failed to migrate to normal gonadal locations. Germ cells are totipotential, undergoing variable differentiation into tissue components that represent derivatives of ectoderm, mesoderm, and endoderm [1 2]. Macroscopically, the cystic teratomas are generally benign, containing sebaceous material and mature tissue. The solid teratomas are frequently malignant, cornposed of immature embryonic tissue in addition to fatty, cartilaginous, fibrous, and bony elements [3-5]. Teratomas occur in many locations, including the ovaries, testes, anterior mediastinum, retroperitoneal space, presacral and coccygeal areas, intracranial sites, neck, and abdomen [1 2]. The size of retroperitoneal teratomas varies, with the largest reported tumor weighing 36 kg [4, 6]. Of the retroperitoneal tumors reported in adults, 26% were malignant. This frequency is higher than the reported frequency of malignancy of teratomas in children, which ranges from 7% to 1 0% [2, 3, 6]. Calcifications, which are visible in 6O-83% of retroperitoneal teratomas on CT scans, cannot predict benignity. Even though 74% of benign teratomas contain calcifications, they also occur in 25% of malignant ones [5, 6]. Evaluation of the size, cystic or solid components, or presence of calcifications cannot consistently indicate malignancy or potential for recurrence [7]. Retroperitoneal teratomas are usually asymptomatic. The clinical features in infancy include a palpable mass or increase in abdominal girth [4, 7]. In adults, benign teratomas are generally symptomatic, characterized by nausea, vomiting, abdominal distension and pain, back pain, edema of the lower extremities, or urinary obstruction in rare instances [1 2, 4]. Malignant teratomas in children and adults tend to progress rapidly and are associated with acute symptoms usually including pain. Metastases to the inguinal region, liver, and ,
,
,
pancreas have been reported [4]. Retroperitoneal teratomas can be imaged by plain radiography, excretory urography, sonography, CT, and MR imaging. Plain radiographs usually show a soft-tissue mass that displaces the bowel. In 61 % of cases, calcification within the tumor or a calcific rim in a cyst wall implies the diagnosis. The characteristic demonstration of bone or teeth is a rare finding in retroperitoneal teratomas [1 4, 6]. Fat may be identified as a radiolucency on radiographs with a detection rate of 60% compared with CT [5]. Sonography can be used to evaluate the cystic, solid, or complex components of the tumor. Specular echoes, acoustic shadowing produced by calcium in the teratoma, and occasionally a fat-fluid level are seen [5, 8]. Sonography, however, may fail to show calcium when compared with CT scans [5]. In addition, the echogenicity of fat varies from echogenic to echolucent, precluding differentiation from other types of soft tissue [5]. As echogenicity depends not on fat alone but also on tissue interfaces with different acoustic impedance, most feel CT is better than sonography for diagnosing fatty tumors [5, 8]. ,
AJR:156,June
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Fig. 4.-case
GENERAL
1991
4: Primary retroperitoneal
tera-
toma. A, Sagittal Ti-weighted (500/20) MR images show a large right-sided retroperitoneal mass. Bulk of tumor consists of fat, which appears as regions of high signal intensity. Calcifications appear as foci of very low intensity. Soft-tissue components of tumor appear as regions of intermediate intensity. B, Sagittal T2-weighted (2000/40) MR images show fat, calcium, and soft-tissue components of retroperitoneal teratoma. c, Longitudinal sonogram shows a 12 x 9 cm right-sided suprarenal teratoma containing a solid hyperechoic fatty component, a heterogeneous component with echogenic foci, and acoustic shadowing produced by calcium in tumor. D, Longitudinal sonogram shows that right kidney is separated from mass and is displaced inferioriy and anteriorly. There is no evidence of hydronephrosis. E, Transaxial contrast-enhanced CT scan shows a well-encapsulated retroperitoneal teratoma that contains multiple tissue elements, including soft tissue, fat, and areas of calcification. F, Gross specimen of predominantly fatty retroperitoneal teratoma.
DIAGNOSIS
CASE
OF THE
DAY
1293
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1294
ESCHELMAN
CT shows the typical attenuation numbers of fat, proteinaceous fluid, and subtle calcifications. An almost pathognomonic CT finding is a fatty portion of the tumor and a horizontal interface with dependent fluid, which probably represents sebum [5, 8]. CT is superior to sonography not only in characterizing retroperitoneal tet atomas but also in defining the tumor extent to surrounding organs and in evaluating the cyst wall [5, 8]. CT, however, cannot reliably demonstrate adherence to adjacent structures but can predict invasion [8]. The value of MR imaging in detecting retroperitoneal tumors has not been fully established. Available information indicates that MR imaging is unable to show calcifications in most of the patients studied with retroperitoneal teratomas [9]. MR imaging, however, can distinguish the fluid, fat, calcium, and soft-tissue elements [9]. Possible uses include determining local spread of tumor, predicting resectability, and evaluating for recurrence. Currently, cross-sectional imaging techniques provide information about the location and morphology of retroperitoneal teratomas. The radiologic findings in this case are characteristic of a retroperitoneal teratoma. Detection of this tumor is essential because ifleft untreated, the mortality rate is essentially 100% [1 4]. Surgery may be difficult when tissue adherence, which occurs in malignant and benign teratomas, hinders complete ,
ET AL.
AJA:156,
June 1991
removal of the tumor [6]. Patients have an excellent prognosis after resection of benign retroperitoneal teratomas [1 4, 6]. Ellen Panageas ,
REFERENCES
1 . Gschwend toma
J, Burke TW, Woodward JE, Holler PB. Aetroperitoneal terapresenting as an abdominal-pelvic mass. Obstet Gyneco/ i987;70:
500-502 2. Engel AM, Elkins AC, Fletcher BD. Retroperitoneal the
literature
1068-1073 3, Lambrianides in adults.
and
presentation
of an unusual
cal review. J Urol 1976;1 15:520-523 5. Davidson AJ, Hartman DS, Goldman 1989;1 72:421
review of i968;22:
teratoma
i987;29:310-312
4. Pantoja E, Liobet A, Gonzalez-Flores
6. Bruneton
Cancer
AL, Walker MM, Rosin RD. Primary retroperitoneal
Urology
pentoneum:
teratoma:
case.
radiologic,
pathologic
B. Retroperitoneal SM.
Mature
and clinical
teratoma:
teratoma
correlation.
histor-
of the retroRadiology
-425
JN, Diard F, Drouillard
JP, Sabatier JC, Tavemier
JF. Primary
retroperitoneal teratoma in adults. Radiology 1980;134:613-616 7. Billmire DF, Grosfeld JL. Teratomas in childhood: analysis of 142 cases. J Pediatr Surg 1986;21 :548-551 8. Friedman AC, Pyatt AS, Hartman DS, Downey EF Jr, Olson WB. CT of benign cystic teratomas. AJR i982;1 38:659-665
9. Cohen MC, Weetman nance
imaging
AM, Provisor AJ, et al. Efficacy of magnetic
in 139 children
with tumors.
Arch Surg
i986;1
reso-
21 :522-529
Downloaded from www.ajronline.org by 192.64.120.147 on 10/07/15 from IP address 192.64.120.147. Copyright ARRS. For personal use only; all rights reserved
,‘
General David
Diagnosis
J. Eschelrnan,1
Case 1: Aneurysm
Ellen
Panageas,
Case of the Day Max
P. Rosen,
Laura
of the Ductus Arteriosus
fewer
than
25 cases
, All
authors:
is a short
reported
Department
AJR 156:1288-1294,
June
tubular
of Radiology,
in the literature.
Boston
University 566-1
John
F. O’Connor
The
,
ductus
Medical
Center,
288 © American
the
,
connection
1991 0361 -803X/91/1
and
allows exposure to the high systemic pressure aorta with subsequent dilatation and aneurysm formation [3, 4]. Some note that many adults with ductus arteriosus aneurysms are hypertensive [5, 6]. Clinically, most signs are related to mass effects. Dyspnea, cough, and transient or persistent dysphonia due to compression of the left recurrent laryngeal nerve are the most common [i 7]. However, in a review of 21 cases, an abnormal chest radiograph was the most common reason for further investigation [5]. Complications such as rupture, dissection, distal embolization, and hemorrhage from fistulous connection to the esophagus or bronchus have been described [1 7]. The average diameter is 5 cm, with one aneurysm as large as 8 x i 1 cm reported [5]. On chest radiographs, the ductus arteriosus aneurysm may be perceived as a change in the contour of the aortic arch or aortopulmonary window. Although adenopathy, neoplasms, or aneurysms related to the aorta itself are certainly more common masses at this site, Danza et al. [7] suggest two radiographic features indicative of a ductus arteriosus aneurysm. These signs are parietal calcification at the periphery of the lesion and/or mottled calcification at the aortic side of the mass in addition to a small pedicle linking the lesion to the pulmonary artery. This pedicle may be obscured with large aneurysms. CT will show the relationship of the aneurysm to within
between the left pulmonary artery and aorta. A remnant of the left sixth aortic arch, it normally undergoes physiologic closure soon after birth, but complete anatomic obliteration requires up to 12 weeks. Aneurysms within the ductus arteriosus usually result from incomplete closure. In the few reports of aneurysms involving a patent ductus arteriosus in adults, it is uncertain whether the ductus arteriosus recanalized or original patency persisted [i]. Normal closure of the ductus arteriosus begins before birth and proceeds from the pulmonary artery to the aortic end. Through a complex process of intimal thickening, endothelial invagination, smooth-muscle cell migration, and hyaluronic acid production, closure of this muscular artery is achieved [2]. When closure is incomplete, the pulmonary side closes and the aortic side remains patent. This may result from increased amounts of elastic tissue within the ductus arteriosus. Therefore, the ductus arteriosus resembles an elastic artery such as the aorta rather than a muscular artery [3}. In addition, low levels of hyaluronic acid have been associated with faulty closure [2]. Patency of the aortic side of the ductus arteriosus
Romo,
arteriosus
A large mediastinal mass was discovered on the chest radiograph (Figs. iA and i B) of a 73-year-old man with wellcontrolled hypertension. Several faint, curvilinear calcifications were noted in the lateral margin of the mass. The superior border of the mass appeared to abut the aorta. Chest CT (Figs. 1 C and 1 D) showed that the enhancing mass originated from the inferior aspect of the aortic arch and extended inferiorly, adjacent to the ascending aorta, to the level of the main pulmonary artery. Aortography (Figs. 1 E and i F) was performed 6 months later after chest radiographs (not shown) revealed enlargement of the mass. Aortography showed the i -cm neck of the aneurysm arising from the inferior surface of this tortuous atherosclerotic aorta, just distal to the left subclavian artery. The remainder of the aneurysm did not opacify because of thrombosis that had occurred since the CT scan was obtained. The patient underwent resection of the 8 x 6 x 6 cm aneurysm of the ductus arteriosus, and the aorta was repaired with a Dacron patch graft. Aneurysm of the ductus arteriosus is a rare entity in adults, with
Vitale
the aortic
and
pulmonary
artery,
while
possibly
revealing
,
88 E. Newton
Roentgen
arch
calcifications not detected by plain radiographs. The diameter of the lesion and presence of mural thrombus also will be identified. Angiography is highly specific, showing the neck of the aneurysm just distal to the origin of the left subclavian artery [1 4, 7]. Unlike true aneurysms of the aortic arch or false aneurysms resulting from trauma or prior aortic dissection, ductus arteriosus aneurysms are saccular, have a narrowed neck at the aortic orifice, and lack severe atheromatous change [5]. Although rare, ductus arteriosus aneurysms require consideration in the differential diagnosis of mediastinal masses because they have a 60% fatality rate due to complications. Criteria for resection include lesions greater than 3 cm in diameter, symptomatic aneurysms, and any that show progressive enlargement. It has been suggested that enlargement is not a finite process; therefore, any ductus arteriosus
St.
Ray Society
, Boston,
MA 021 1 8. Address
reprint
requests
to J. F. O’Connor.
Downloaded from www.ajronline.org by 192.64.120.147 on 10/07/15 from IP address 192.64.120.147. Copyright ARRS. For personal use only; all rights reserved
A
Fig. 1.-Case arteriosus.
1: Aneurysm
of ductus
A and B, Posteroanterior (A) and lateral (B) chest radiographs show a mediastinal mass in aortopulmonary win-
dow, which appears
to abut aorta on
lateral radiograph. Several thin, curvilinear calcifications are seen in lateral border of this mass. C and D, Axial CT scans at level of aortic arch (C, unenhanced) and carina (D, enhanced). Neck of aneurysm
arises arch.
from inferior Enhancing
aspect
of aortic
8 x 6 x 6 cm aneurysm
extends inferiorly, adjacent to ascending aorta,
to level
of main
pulmonary
artery. E and F, Subtracted left anterior oblique(E) and anteroposterior(F) projections from aortogram show 1-cm neck of aneurysm arising from inferior aspect of aortic arch, just distal to origin of left subclavian artery. This examination was performed 6 months after CT scanning, during which time
thrombus formed within aneurysm. A large soft-tissue mass corresponding to aneurysm is seen on anteroposterior projection lateral to neck of aneurysm in aortopulmonary window. Remainder of aorta is tortuous and atherosclerotic with ulcerating plaque.
‘
i 290
aneurysms, moved[i,
ESCHELMAN
regardless
of size
or symptoms,
should
be re-
Downloaded from www.ajronline.org by 192.64.120.147 on 10/07/15 from IP address 192.64.120.147. Copyright ARRS. For personal use only; all rights reserved
REFERENCES PD, Wojtowycz
MM, Karwande
SV, et al. Roentgenologic
CPC:
enlarging mediastinal mass. Invest Radiol 1987;22:240-243 2. DeReeder EG, Girard N, Poelmann RE, Van Munsteren JC, Patterson DF, Gittenberger-De Greet AC. Hyaluronic acid accumulation and endothelial cell detachment in intimal thickening of the vessel wall: the normal and genetically defective ductus arteriosus. Am J Pathol 1988;132:574-585 3, Gittenberger-De Greet AC. Persistent ductus arteriosus: most probably a primary congenital malformation. Br Heart J 1977;39:610-618
4. Cohen BA, Efremidis SC, Dan SJ, Robinson B, Rabinowitz
6. Borow KM, Hessel SJ, Sloss LI. Fistulous aneurysm of ductus arteriosus. Br Heart J 1981;45:467-470
7. Danza FM, Fusco A, Breda M, Bock aneurysm
The initial
appearance
of breast carcinoma as dense intrais exceptionally rare. However, Bruwer et al. [1 ] have described this appearance of punctate intranodal densities in patients receiving intramuscular gold injections for rheumatoid arthritis. Gold therapy may be very effective for active rheumatoid arthritis, possibly delaying or preventing the progression of erosions in some patients [2]. Although approximately half of the injected gold is eliminated via urine and stool, the rest remains in the body, often for years after therapy is stopped. Organs retaining the highest concentrations of injected gold are lymph nodes, adrenal glands, liver, kidneys, bone marrow, and spleen [i]. David J. Eschelman
JG. Aneurysm
of the ducts arteriosus in an adult. J Comput Assist Tomogr 1981;5: 421-423 5. Mitchell RS, Seifert FC, Miller DC, Jamieson SW, Shumway NE. Aneurysm of the diverticulum of the ductus arteriosus in the adult: successful surgical treatment in five patients and review of the literature. J Thorac Cardiovasc Surg 1983;86:400-408
arteriosus
AJR:156, June 1991
nodal microcalcifications
5]. Laura Vitale Romo David J. Eschelman
1 . Traughber
ET AL.
in an adult.
AiR
E, Lemmo G, Colavita 1984;143: 131-133
N. Ductus
REFERENCES 1 . Bruwer A, Nelson GW, Spark RP. Punctate simulating microcalcifications on mammograms.
87-88 2. Abramowicz 1989;31
M, ed. Drugs for rheumatoid
in Woman
with
A 45-year-old woman with a long history of chrysotherapy for rheumatoid arthritis had screening mammography. Routine mediolateral oblique views (Figs. 2A and 2B) revealed innumerable punctate densities in several axillary lymph nodes on both sides. A magnificaton view (Fig. 2C) showed the fine, intranodal, linear and punctate densities.
arthritis. Med Left Drugs
Ther
:61-64
Case 3: Giant-Cell Case 2: Intranodal Gold Deposits Rheumatoid Arthritis
intranodal gold deposits Radiology 1987;1 63:
Tumor of the Temporal
Bone
A 25-year-old man came to the emergency department with swelling on the right side of his head that had progressed for several months. He denied any history of trauma. A lateral skull radiograph (Fig. 3A) showed an expansile, lytic lesion involving the temporal bone. An unenhanced CT scan of the head at soft-tissue window settings showed that the central portion of the lesion contained heterogeneous soft tissue and calcifications (Fig. 3B). Images filmed at bone
GENERAL
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AJR:156, June 1991
Fig. 3.-Case
3: Giant-cell
tumor of the temporal
DIAGNOSIS
CASE
OF
THE
1291
DAY
bone.
A, Lateral skull radiograph shows an expansile, lytic lesion involving temporal bone. B, Axial unenhanced CT scan of head obtained with soft-tissue window sethngs shows that center of lesion contains heterogeneous soft tissue and calcifications. C, Axial unenhanced CT scan of head obtained with bone windows shows that lesion has greatly expanded diploic space. Lesion extends into anterior portion of petrous bone. D, Axial Ti-weighted (500/15) MR image of head after IV administration of gadopentetate dimeglumine shows lesion is composed of two distinct tissues. When compared with unenhanced Ti-weighted image (E), medial portion enhances, consistent with a solid component. Outer portion, which contains septa but does not enhance, is suggestive of a cystic component. E, Coronal Ti-weighted (560/15) unenhanced MR image of head shows encroachment of diploic space at base of skull, compression of temporal lobe, and distortion of middle cranial fossa. F, Axial T2-weighted (3000/90) MR image of head shows bright signal from outer aspect of lesion, which confirms presence of a lateral cystic component. Signal from inner portion of lesion is dark, consistent with a solid component.
windows
diploic
showed
that
a solid
and that
the
lesion
had
greatly
expanded
the
extended into the anterior portion of the petrous bone (Fig. 3C). MR images of the head were then obtained. After IV administration of gadopentetate dimeglumine, Ti-weighted (500/1 5) axial MR images showed that the lesion was composed of two distinct tissues (Fig. 3D). When compared with unenhanced Ti -weighted images (Fig. 3E), the medial portion enhanced, which was consistent with
space
component.
the lesion
The
septa but did not enhance, ponent. Axial T2-weighted
lateral
portion,
was suggestive (3000/90) MR
which
contained
of a cystic cornimages (Fig. 3F)
showed which
bright
signal
from
the
presence
confirmed
the
outer
The signal from the inner portion consistent with a solid component. Giant-cell
occur 6O%) may The ologic
tumors
classically
involve
especially
giant-cell
radiation
component.
lesion
long
was
tubular
dark, bones,
and have a high (40Malignant degeneration therapy
granuloma,
has been described appearance. This entity
entity,
radiologic
after
reparative
of the lesion,
cystic
of the
in the third to fourth decades, recurrence rate after resection. occur,
aspect
of a lateral
a separate
clinicopath-
and may have an identical is a reactive granulomatous
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1292
ESCHELMAN
process in response to intraosseous hemorrhage or inflammation. Often a history of trauma can be elicited. This lesion most commonly involves the mandible and maxilla and occurs in the first and second decades. The course is always benign. Curettage is usually the only treatment needed. Recurrence is extremely rare [1 2]. Both giant-cell tumors and giant-cell reparative granulomas have been reported in the temporal bone. Pathologic differentiation between these two entities is often very difficult and depends on the local distribution and shape of the giant cells, the presence or absence of hemosiderin and osteoid, and the shape of the stromal fibroblasts [2]. By 1 974 there had been 23 reported cases of giant-cell tumor of the temporal bone. In 1 974 all cases were reviewed, and I 8 of the 23 cases were reclassified as giant-cell reparative granulomas [2]. Between 1980 and 1 990, several published cases of similar lesions [3-9] have been reported as giant-cell tumors. Max P. Rosen ,
REFERENCES 1 . Resnick D, Kyriakos M, Gleenway GD. In: Resnick D, Naiwayama G, eds. Diagnosis of bone and joint disorders, 2nd ed. Philadelphia: Saunders, 1988:3757-3776 2. Hirschl 5, Katz A. Giant cell reparative granuloma outside the jaw bone. Hum Pathol i975;5:171-181 3, Cook HF, Miller R, Yamada A. Giant cell tumor of the infratemporal fossa: report of case. J Oral Maxiiofac Surg 1986;44: 651-656 4. Wilbur AC, Choi KH, Tan WS, Jafar JJ, Spigos DG. Giant cell tumor of the sphenoid bone mimicking a pituitary tumor. AJNR 1986;7:361-362 5. KiwitJCW, Schober R, Nicola N, Schirmer M, Wechsler W. Osteoclastomas of the petrous bone. Surg Neurol i986;26:59-62 6. Carmody RF, Rickles DJ, Johnson SF. Giant cell tumor of the sphenoid bone. J Comput Assist Tomogr 1983;7 :370-373 7. Tandon DA, Deka AC, Chaudhary C. Misra NK. Giant cell tumor of the temporosphenoidal region. J Laryngo/ Otol i988;102:449-451 8. Findlay JM, Chiasson D, Hudson AR, Chuli M. Giant cell tumor of the middle cranial fossa. J Neurosurg 1987;66:924-928 9. Henderson BTH, Whitwell H. Giant cell tumor of the skull: case report. Neurosurgery i988;23: 120-1 22
Case 4: Primary
Retropentoneal
Teratoma
This previously healthy 25-year-old woman had persistent lower back pain for 2 months after a motor vehicle accident. MR images (Figs. 4A and 4B) showed a right-sided retroperitoneal mass with signal intensities corresponding to fat, calcium, and soft-tissue components. The sonographic study (Figs. 4C and 4D) showed a solid suprarenal tumor containing a hyperechoic region consistent with fat and a heterogeneous region with focal calcifications. To better evaluate these tissue elements, CT was performed (Fig. 4E), verifying the large adipose component as well as the calcified and soft-tissue areas in this well-encapsulated tumor. At surgery, the right adrenal gland was found to be normal and the retroperitoneal mass was completely resected. Pathologic examination of the specimen revealed a mature retroperitoneal teratoma (Fig. 4F). Primary retroperitoneal teratornas are rare, representing 51 0% of primary retroperitoneal tumors [1 ]. The mean age of
ET
AL.
AJR:156,
June
1991
patients ranges between 1 3 and 16 years, with cases reported in a fetus and in patients up to 82 years old [2-4]. Fewer than 1 0-20% occur after the age of 30 years, with 43-55% diagnosed in the first decade of life [4]. Most authors have reported a higher prevalence among females. Teratomas derive from germ cells that failed to migrate to normal gonadal locations. Germ cells are totipotential, undergoing variable differentiation into tissue components that represent derivatives of ectoderm, mesoderm, and endoderm [1 2]. Macroscopically, the cystic teratomas are generally benign, containing sebaceous material and mature tissue. The solid teratomas are frequently malignant, cornposed of immature embryonic tissue in addition to fatty, cartilaginous, fibrous, and bony elements [3-5]. Teratomas occur in many locations, including the ovaries, testes, anterior mediastinum, retroperitoneal space, presacral and coccygeal areas, intracranial sites, neck, and abdomen [1 2]. The size of retroperitoneal teratomas varies, with the largest reported tumor weighing 36 kg [4, 6]. Of the retroperitoneal tumors reported in adults, 26% were malignant. This frequency is higher than the reported frequency of malignancy of teratomas in children, which ranges from 7% to 1 0% [2, 3, 6]. Calcifications, which are visible in 6O-83% of retroperitoneal teratomas on CT scans, cannot predict benignity. Even though 74% of benign teratomas contain calcifications, they also occur in 25% of malignant ones [5, 6]. Evaluation of the size, cystic or solid components, or presence of calcifications cannot consistently indicate malignancy or potential for recurrence [7]. Retroperitoneal teratomas are usually asymptomatic. The clinical features in infancy include a palpable mass or increase in abdominal girth [4, 7]. In adults, benign teratomas are generally symptomatic, characterized by nausea, vomiting, abdominal distension and pain, back pain, edema of the lower extremities, or urinary obstruction in rare instances [1 2, 4]. Malignant teratomas in children and adults tend to progress rapidly and are associated with acute symptoms usually including pain. Metastases to the inguinal region, liver, and ,
,
,
pancreas have been reported [4]. Retroperitoneal teratomas can be imaged by plain radiography, excretory urography, sonography, CT, and MR imaging. Plain radiographs usually show a soft-tissue mass that displaces the bowel. In 61 % of cases, calcification within the tumor or a calcific rim in a cyst wall implies the diagnosis. The characteristic demonstration of bone or teeth is a rare finding in retroperitoneal teratomas [1 4, 6]. Fat may be identified as a radiolucency on radiographs with a detection rate of 60% compared with CT [5]. Sonography can be used to evaluate the cystic, solid, or complex components of the tumor. Specular echoes, acoustic shadowing produced by calcium in the teratoma, and occasionally a fat-fluid level are seen [5, 8]. Sonography, however, may fail to show calcium when compared with CT scans [5]. In addition, the echogenicity of fat varies from echogenic to echolucent, precluding differentiation from other types of soft tissue [5]. As echogenicity depends not on fat alone but also on tissue interfaces with different acoustic impedance, most feel CT is better than sonography for diagnosing fatty tumors [5, 8]. ,
AJR:156,June
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Fig. 4.-case
GENERAL
1991
4: Primary retroperitoneal
tera-
toma. A, Sagittal Ti-weighted (500/20) MR images show a large right-sided retroperitoneal mass. Bulk of tumor consists of fat, which appears as regions of high signal intensity. Calcifications appear as foci of very low intensity. Soft-tissue components of tumor appear as regions of intermediate intensity. B, Sagittal T2-weighted (2000/40) MR images show fat, calcium, and soft-tissue components of retroperitoneal teratoma. c, Longitudinal sonogram shows a 12 x 9 cm right-sided suprarenal teratoma containing a solid hyperechoic fatty component, a heterogeneous component with echogenic foci, and acoustic shadowing produced by calcium in tumor. D, Longitudinal sonogram shows that right kidney is separated from mass and is displaced inferioriy and anteriorly. There is no evidence of hydronephrosis. E, Transaxial contrast-enhanced CT scan shows a well-encapsulated retroperitoneal teratoma that contains multiple tissue elements, including soft tissue, fat, and areas of calcification. F, Gross specimen of predominantly fatty retroperitoneal teratoma.
DIAGNOSIS
CASE
OF THE
DAY
1293
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1294
ESCHELMAN
CT shows the typical attenuation numbers of fat, proteinaceous fluid, and subtle calcifications. An almost pathognomonic CT finding is a fatty portion of the tumor and a horizontal interface with dependent fluid, which probably represents sebum [5, 8]. CT is superior to sonography not only in characterizing retroperitoneal tet atomas but also in defining the tumor extent to surrounding organs and in evaluating the cyst wall [5, 8]. CT, however, cannot reliably demonstrate adherence to adjacent structures but can predict invasion [8]. The value of MR imaging in detecting retroperitoneal tumors has not been fully established. Available information indicates that MR imaging is unable to show calcifications in most of the patients studied with retroperitoneal teratomas [9]. MR imaging, however, can distinguish the fluid, fat, calcium, and soft-tissue elements [9]. Possible uses include determining local spread of tumor, predicting resectability, and evaluating for recurrence. Currently, cross-sectional imaging techniques provide information about the location and morphology of retroperitoneal teratomas. The radiologic findings in this case are characteristic of a retroperitoneal teratoma. Detection of this tumor is essential because ifleft untreated, the mortality rate is essentially 100% [1 4]. Surgery may be difficult when tissue adherence, which occurs in malignant and benign teratomas, hinders complete ,
ET AL.
AJA:156,
June 1991
removal of the tumor [6]. Patients have an excellent prognosis after resection of benign retroperitoneal teratomas [1 4, 6]. Ellen Panageas ,
REFERENCES
1 . Gschwend toma
J, Burke TW, Woodward JE, Holler PB. Aetroperitoneal terapresenting as an abdominal-pelvic mass. Obstet Gyneco/ i987;70:
500-502 2. Engel AM, Elkins AC, Fletcher BD. Retroperitoneal the
literature
1068-1073 3, Lambrianides in adults.
and
presentation
of an unusual
cal review. J Urol 1976;1 15:520-523 5. Davidson AJ, Hartman DS, Goldman 1989;1 72:421
review of i968;22:
teratoma
i987;29:310-312
4. Pantoja E, Liobet A, Gonzalez-Flores
6. Bruneton
Cancer
AL, Walker MM, Rosin RD. Primary retroperitoneal
Urology
pentoneum:
teratoma:
case.
radiologic,
pathologic
B. Retroperitoneal SM.
Mature
and clinical
teratoma:
teratoma
correlation.
histor-
of the retroRadiology
-425
JN, Diard F, Drouillard
JP, Sabatier JC, Tavemier
JF. Primary
retroperitoneal teratoma in adults. Radiology 1980;134:613-616 7. Billmire DF, Grosfeld JL. Teratomas in childhood: analysis of 142 cases. J Pediatr Surg 1986;21 :548-551 8. Friedman AC, Pyatt AS, Hartman DS, Downey EF Jr, Olson WB. CT of benign cystic teratomas. AJR i982;1 38:659-665
9. Cohen MC, Weetman nance
imaging
AM, Provisor AJ, et al. Efficacy of magnetic
in 139 children
with tumors.
Arch Surg
i986;1
reso-
21 :522-529
