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609
CT and MR Imaging Findings Adults with Cerebellar Medulloblastoma: Comparison Findings
H Pierre M. Bourgoui&’2 Donatella Tampieri1 Stephen Z. Grahova&’3 Christian L#{233}ger Raquel Del Carpi& Denis Melan#{231}on1
in with
in Children
:
#{149}
.
.
,
The goal of this study was to determine if certain imaging features suggest the diagnosis of cerebellar medulloblastoma in adults and to determine how often the classic CT appearance seen in children is present in adults. The study included 28 adult patients with proved cerebellar medulloblastoma. The tumor was located in the cerebellar vermis in 14 patients and in a cerebellar hemisphere in 14 patients. Thirteen patients had unenhanced CT of the brain, all patients had contrast-enhanced CT, and eight patients had unenhanced MR imaging. The imaging features in adults were compared with those in children, as described in the literature. In our adult patients, all tumors were hyperdense compared with gray matter on unenhanced CT and showed a slight to moderate increase in density after injection of contrast medium. Thirteen lesions had well-defined margins, and 15 had poorly defined margins Low-density areas consistent with cystic and necrotic degeneration were detected in 23 (82%) of the 28 tumors. By comparison, in children, medulloblastoma usually originates in the vermis. As in adults, the mass is hyperdense on unenhanced CT, but enhances markedly and homogeneously after injection of contrast medium. Usually no evidence of cyst formation or necrosis
is seen,
and
of medulloblastoma Medulloblastoma
the
tumor
in children has
margins
was
a variable
identified MR
are
well in
defined.
only
appearance
three
in both
This
classic
CT appearance
(1 1%) of the 28 adult patients. children
and
adults.
On
T2-
weighted images, lesions are hype-, iso-, or hypenntense compared with normal gray matter. The CT findings of medulloblastoma in adults usually differ from those of medulloblastoma in children. The tumor has a variable and nonspecific appearance in adults and should always be considered in the differential diagnosis of a mass in the posterior fossa. AJR
159:609-612,
September
1992
Cerebellar
Received October 23, 1 991 ; accepted after revision April 10, 1992. 1 Department of Radiology, Montreal Neurologi-
cal Hospital and Institute, McGill University, tr#{233}al, Qu#{233}bec, Canada H3A 2B4. 2
Present
HOpital
address:
Notre-Dame,
Department
of
Mon-
Radiology,
Universit#{233}de Montr#{233}al,Mon-
treal General Hospital, McGill University, 1560 Sherbrooke St. E., Montr#{233}al, Qu#{233}bec, Canada, H2L 4M1 . Address reprint requests to P. M. Bourgouin. 3
tawa
Present address: Department of Radiology, OtGeneral Hospital, University of Ottawa,
Ottawa,
Ontario,
Canada
for about
described [i-8]. A hyperdense midline marked and homogeneous enhancement
mass on unenhanced CT that displays after injection of contrast medium is
strongly suggestive of the diagnosis. Few reports have specifically discussed the tumor in adults [9, i 0]. The goal of this study was to determine if certain imaging features strongly suggest the diagnosis in adults and how often the class CT appearance of medulloblastoma described in children is seen in adults.
K1H 8L6.
of Computer Sciences and Operational Research, Universit#{233}do Montr#{233}al,Montr#{233}al, Qu#{233}bec,Canada H3C 3J7. 4
medulloblastoma most frequently occurs during childhood, when it 15% of all brain tumors [i -3]. This neoplasm is uncommon in adults. According to the Connecticut Tumor Registry [2], medulloblastoma accounts for only 0.4% of all brain tumors in adults. The CT appearance of cerebellar medulloblastoma in children has been well accounts
Department
0361 -803X/92/1 593-0609 ©American Roentgen Ray Society
Materials
and Methods
This study included 28 adults, 1 5 men and 1 3 women, with medulloblastoma, who were evaluated and treated at the Montreal
Ottawa
General,
and Ottawa
Civic hospitals
between
histopathologically proved Neurological, Notre-Dame,
1978 and 1990. The age range was
BOURGOUIN
Downloaded from www.ajronline.org by UCSF LIB & CKM/RSCS MGMT on 04/25/15 from IP address 169.230.243.252. Copyright ARRS. For personal use only; all rights reserved
610
18-47 years (mean, 28 years). Seventeen patients were 18-30 years old, eight patients were 30-40 years old, and three patients were more than 40 years old. All patients had a mass in the posterior
ET AL.
AJR:159,
compared tumor
with size;
and
The
imaging
The epicenter of the tumor was located in the cerebellar vermis in 14 patients and in a cerebellar hemisphere in 14 patients. All patients had radical excision of the tumor, followed by radiation therapy. Histopathologic studies were performed on the resected specimens to detect the presence of desmoplasia. Tissues were stained with hematoxylin and eosin and by using Gomori’s reticulin method. Eight
with
those
ture
[1-8].
(29%)
CT Findings
of 28 tumors
showed
evidence
of desmoplasia.
Desmoplasia
=
(400-600/20-30/2 [TR/TE/excitations]), proton density-weighted images (2000-2300/30-40/2), and T2-weighted images (2000-2300/ 80-90/2) were obtained in all patients. All studies were performed on
1 .5-T systems, orthogonal
planes.
and images The
were always
obtained
CT and MR examinations
in at least two were
reviewed
by
two neuroradiologists, and the following features analyzed: tumor density compared with the density of normal gray matter, before and after injection of contrast medium; signal intensity of the tumor
of normal
gray
matter;
nature
of tumor
margins;
of cysts and necrosis, calcifications,
presence
edema,
and hydrocephalus.
fossa.
was detected in three (21 %) of 14 patients with vermian tumors and in five (36%) of 14 patients with hemispheric tumors. No statistical correlation between location of tumor and presence of desmoplasia was found (p .40). All patients had contrast-enhanced CT of the brain before surgery. In addition, 13 patients had unenhanced CT. Eight patients had unenhanced MR imaging. Multislice spin-echo Ti -weighted images
that
September1992
features
of medulloblastoma
of medulloblastoma
in adults
in children,
were
as described
compared in the
litera-
Results
All tumors were hyperdense compared with normal gray matter on contrast-enhanced CT. In the i 3 patients who had unenhanced CT, all tumors were hyperdense compared with gray matter and showed mild to moderate enhancement after injection of contrast medium. Thirteen lesions had well-defined margins, and i 5 had poorly defined margins. A majority (64%) of vermian tumors had well-defined margins, whereas only 29% of hemispheric lesions had well-defined margins.
The mean diameter of tumors was 4.6 cm (±i .2 cm SD). Areas of low density (usually
609
CT and MR Imaging Findings Adults with Cerebellar Medulloblastoma: Comparison Findings
H Pierre M. Bourgoui&’2 Donatella Tampieri1 Stephen Z. Grahova&’3 Christian L#{233}ger Raquel Del Carpi& Denis Melan#{231}on1
in with
in Children
:
#{149}
.
.
,
The goal of this study was to determine if certain imaging features suggest the diagnosis of cerebellar medulloblastoma in adults and to determine how often the classic CT appearance seen in children is present in adults. The study included 28 adult patients with proved cerebellar medulloblastoma. The tumor was located in the cerebellar vermis in 14 patients and in a cerebellar hemisphere in 14 patients. Thirteen patients had unenhanced CT of the brain, all patients had contrast-enhanced CT, and eight patients had unenhanced MR imaging. The imaging features in adults were compared with those in children, as described in the literature. In our adult patients, all tumors were hyperdense compared with gray matter on unenhanced CT and showed a slight to moderate increase in density after injection of contrast medium. Thirteen lesions had well-defined margins, and 15 had poorly defined margins Low-density areas consistent with cystic and necrotic degeneration were detected in 23 (82%) of the 28 tumors. By comparison, in children, medulloblastoma usually originates in the vermis. As in adults, the mass is hyperdense on unenhanced CT, but enhances markedly and homogeneously after injection of contrast medium. Usually no evidence of cyst formation or necrosis
is seen,
and
of medulloblastoma Medulloblastoma
the
tumor
in children has
margins
was
a variable
identified MR
are
well in
defined.
only
appearance
three
in both
This
classic
CT appearance
(1 1%) of the 28 adult patients. children
and
adults.
On
T2-
weighted images, lesions are hype-, iso-, or hypenntense compared with normal gray matter. The CT findings of medulloblastoma in adults usually differ from those of medulloblastoma in children. The tumor has a variable and nonspecific appearance in adults and should always be considered in the differential diagnosis of a mass in the posterior fossa. AJR
159:609-612,
September
1992
Cerebellar
Received October 23, 1 991 ; accepted after revision April 10, 1992. 1 Department of Radiology, Montreal Neurologi-
cal Hospital and Institute, McGill University, tr#{233}al, Qu#{233}bec, Canada H3A 2B4. 2
Present
HOpital
address:
Notre-Dame,
Department
of
Mon-
Radiology,
Universit#{233}de Montr#{233}al,Mon-
treal General Hospital, McGill University, 1560 Sherbrooke St. E., Montr#{233}al, Qu#{233}bec, Canada, H2L 4M1 . Address reprint requests to P. M. Bourgouin. 3
tawa
Present address: Department of Radiology, OtGeneral Hospital, University of Ottawa,
Ottawa,
Ontario,
Canada
for about
described [i-8]. A hyperdense midline marked and homogeneous enhancement
mass on unenhanced CT that displays after injection of contrast medium is
strongly suggestive of the diagnosis. Few reports have specifically discussed the tumor in adults [9, i 0]. The goal of this study was to determine if certain imaging features strongly suggest the diagnosis in adults and how often the class CT appearance of medulloblastoma described in children is seen in adults.
K1H 8L6.
of Computer Sciences and Operational Research, Universit#{233}do Montr#{233}al,Montr#{233}al, Qu#{233}bec,Canada H3C 3J7. 4
medulloblastoma most frequently occurs during childhood, when it 15% of all brain tumors [i -3]. This neoplasm is uncommon in adults. According to the Connecticut Tumor Registry [2], medulloblastoma accounts for only 0.4% of all brain tumors in adults. The CT appearance of cerebellar medulloblastoma in children has been well accounts
Department
0361 -803X/92/1 593-0609 ©American Roentgen Ray Society
Materials
and Methods
This study included 28 adults, 1 5 men and 1 3 women, with medulloblastoma, who were evaluated and treated at the Montreal
Ottawa
General,
and Ottawa
Civic hospitals
between
histopathologically proved Neurological, Notre-Dame,
1978 and 1990. The age range was
BOURGOUIN
Downloaded from www.ajronline.org by UCSF LIB & CKM/RSCS MGMT on 04/25/15 from IP address 169.230.243.252. Copyright ARRS. For personal use only; all rights reserved
610
18-47 years (mean, 28 years). Seventeen patients were 18-30 years old, eight patients were 30-40 years old, and three patients were more than 40 years old. All patients had a mass in the posterior
ET AL.
AJR:159,
compared tumor
with size;
and
The
imaging
The epicenter of the tumor was located in the cerebellar vermis in 14 patients and in a cerebellar hemisphere in 14 patients. All patients had radical excision of the tumor, followed by radiation therapy. Histopathologic studies were performed on the resected specimens to detect the presence of desmoplasia. Tissues were stained with hematoxylin and eosin and by using Gomori’s reticulin method. Eight
with
those
ture
[1-8].
(29%)
CT Findings
of 28 tumors
showed
evidence
of desmoplasia.
Desmoplasia
=
(400-600/20-30/2 [TR/TE/excitations]), proton density-weighted images (2000-2300/30-40/2), and T2-weighted images (2000-2300/ 80-90/2) were obtained in all patients. All studies were performed on
1 .5-T systems, orthogonal
planes.
and images The
were always
obtained
CT and MR examinations
in at least two were
reviewed
by
two neuroradiologists, and the following features analyzed: tumor density compared with the density of normal gray matter, before and after injection of contrast medium; signal intensity of the tumor
of normal
gray
matter;
nature
of tumor
margins;
of cysts and necrosis, calcifications,
presence
edema,
and hydrocephalus.
fossa.
was detected in three (21 %) of 14 patients with vermian tumors and in five (36%) of 14 patients with hemispheric tumors. No statistical correlation between location of tumor and presence of desmoplasia was found (p .40). All patients had contrast-enhanced CT of the brain before surgery. In addition, 13 patients had unenhanced CT. Eight patients had unenhanced MR imaging. Multislice spin-echo Ti -weighted images
that
September1992
features
of medulloblastoma
of medulloblastoma
in adults
in children,
were
as described
compared in the
litera-
Results
All tumors were hyperdense compared with normal gray matter on contrast-enhanced CT. In the i 3 patients who had unenhanced CT, all tumors were hyperdense compared with gray matter and showed mild to moderate enhancement after injection of contrast medium. Thirteen lesions had well-defined margins, and i 5 had poorly defined margins. A majority (64%) of vermian tumors had well-defined margins, whereas only 29% of hemispheric lesions had well-defined margins.
The mean diameter of tumors was 4.6 cm (±i .2 cm SD). Areas of low density (usually
