Downloaded from www.ajronline.org by 201.62.50.27 on 11/09/15 from IP address 201.62.50.27. Copyright ARRS. For personal use only; all rights reserved
1031
Primary Malignant Small Round Cell Tumor of the Abdomen: CT Findings
in Five Cases
Malignant small round cell tumor of the abdomen is a newly described clinicopathoDatla G. K. Varma1 logic entity. The features of this entity include a predilection for young men, predominant Kelvin McDaniel1 location, and aggressive behavior. Pathologic analysis demonstrates a Nelson G. Ord#{244}#{241}ez2 abdominopelvic small-cell tumor unusually coexpressing desmin and keratin. This study describes CT Christine A. J. Granfiel& characteristics in five patients with malignant small round cell tumor of the abdomen. Chusilp Charnsangavej1 All patients were young white men, 20-36 years old (mean, 28 years). In all five cases, Sidney Wallace1 CT
scans
surfaces
revealed
lobulated
and predominantly
and pelvis
(two cases);
masses were centrally iodinated
contrast
masses
appearing
the
involving
diffuse abdominopelvic necrotic and enhanced
material.
Additional
to arise
primarily from peritoneal of the abdomen (two cases) involvement was noted in one case. The inhomogeneously after administration of
peritoneal
cavity
CT features
included
ascites
(one case),
calcifi-
cations in the dominant mass (one case), omental implants (two cases), hydronephrosis (four cases), anterior diaphragmatic lymphadenopathy (two cases), liver metastases (two cases), and retroperitoneal lymphadenopathy (two cases). CT findings of abdominal malignant small round cell tumor are nonspecific and mimic findings noted in other conditions, such as pentoneal carcinomatosis and leiomyosarcomatosis. AJR
158:1031-1034,
May
1992
A distinctive type of malignant small round cell tumor of the abdomen has been recently described in the pathologic literature [1-4]. Unique features of this neoplasm include a predilection for young men, predominant location in the peritoneal cavity with a possible predilection for the pelvic region, and aggressive behavior with high mortality despite multiple modes of therapy [2]. Immunohistochemical studies are unique in this entity in that there is coexpression of keratin and desmin indicating the presence of epithelial and muscle-associated antigens [1 2]. To our knowledge, malignant small round cell tumor of the abdomen has not been previously reported in the radiologic literature. Abdominal CT findings in five patients with malignant small round cell tumor of the abdomen are the subject of this report. ,
Materials
and
We searched Received revision
November 13, 1991 December 16, 1991.
;
accepted
after
2
Department
of Pathology, Cancer
The
0361-803X/92/1 585-1031 CAmerican
Roentgen
University
of
Center, Houston, TX
77030. Ray SOciety
with
abdomen
I Department of Diagnostic Radiology, Box 57, The University of Texas M. D. Anderson Cancer Center, 1515 HOICOmbO Blvd., Houston, TX 77030. Address reprint requests to D. G. K. Varma.
Texas M. D. Anderson
patients
Methods
the consultation
malignant
and pelvis had
files of one of the authors
small
round
cell tumor
been
obtained.
and found the records
of the abdomen
in whom
The CT scans were reviewed
CT scans
retrospectively.
of five of the
All five
patients were young white men 20-36 years old (mean, 28 years). The patients had no clinical evidence of AIDS. Two patients tested negative for antibodies to HIV; the other patients were not tested. The patients had palpable abdominal and/or pelvic masses. One patient
also
had an enlarged
metastatic
left anterior
cervical
lymph
node.
Signs
and
symptoms
were related to mass effect on contiguous organs. Diagnosis was based on pathologic examination of tissue specimens obtained during exploratory laparotomy (four cases) and from a resected
cervical
lymph
was done by one of the authors,
node (one case).
The histopathologic diagnosis of this tumor small round cell tumor of the
who is familiar with malignant
1032
VARMA
abdomen
[1].
Immunohistochemical
studies
were
performed
in all
cases by using the avidin-biotin-peroxidase complex method [5]. The details of additional immunostaining procedures performed are de-
Downloaded from www.ajronline.org by 201.62.50.27 on 11/09/15 from IP address 201.62.50.27. Copyright ARRS. For personal use only; all rights reserved
scribed
elsewhere
[6]. Tissue
for electron
microscopy
studies
was
available in one case. CT scans were obtained with a GE 9800 scanner(General Electric, Milwaukee, WI) in three cases and with GE 8800 and Picker 1200 SX (Picker International, Highland Heights, OH) scanners in one case each. The scans consisted of contiguous 1 .0-cm-thick sections. In all patients scans were obtained after IV infusion of 150 ml of contrast material and with oral and rectal administration of diluted barium. In three
patients,
injector
IV contrast
material
was
administered
at 1 .5 mI/sec with a 60-sec delay; in
drip infusion
technique
was used.
two
In two patients,
AJR:158,
May 1992
tures included ascites (one case), omental implants (two cases), hydronephrosis (four cases), anterior diaphragmatic lymphadenopathy (two cases), liver metastases (two cases), and retroperitoneal lymphadenopathy (two cases)(Figs. 2 and 4). The hydronephrosis was caused by the pelvic masses impinging on the ureters; the masses also abutted loops of bowel causing symptoms of intermittent bowel obstruction.
Pathology
via power
patients,
a rapid
unenhanced
scans
were also obtained. The CT scans were analyzed for anatomic location of tumor, morphologic characteristics, extent of disease, and associated findings.
Results In all five cases, CT scans revealed lobulated masses appearing to arise from peritoneal surfaces and ranging in size from 5 x 4 cm to 1 5 x 8 cm. In two cases, the masses were located predominantly in the peritoneal cavity of the left abdomen extending inferiorly from the greater curvature of the stomach to the level of the lower pole of the kidneys (Figs. 1 and 2). The masses were centrally necrotic and enhanced inhomogeneously after administration of iodinated contrast material; one tumor demonstrated foci of calcification (Fig. 2). A smaller pelvic component posterior to the urinary bladder was also noted in one of these tumors. In two patients, large lobulated masses were identified in the pelvis posterior to the bladder and anterior to the rectum (Fig. 3), and one patient had diffuse abdominopelvic involvement. Additional CT fea-
A
ET AL.
Histologically, the five tumors were similar (Fig. 5). They were made up of well-defined, solid clusters of small tumor cells separated by dense fibrous stroma. The larger tumor nests had central necrosis, and mitotic figures were frequent. lmmunocytochemical studies demonstrated that the tumor cells stained with keratin in all cases; in addition to keratin, most tumor cells also reacted with desmin and vimentin. No reactivity for chromogranin A or S-i 00 protein was seen in any of the cases. The most striking ultrastructural feature was the presence of large amounts of intracytoplasmic intermediate filaments that often formed paranuclear bundles and whorls. No neuroendocrine granules were seen.
Discussion Malignant small round cell tumor of the abdomen appears to be a distinct clinicopathologic entity belonging to the generic category of small round cell tumors of infancy and childhood [2, 7, 8]. The category of small round cell tumors of infancy and childhood includes Ewing’s sarcoma, primitive neuroectodermal tumor, embryonal and rhabdomyosarcoma,
B Fig. 1.-32-year-old
A, Contrast-enhanced abdomen. B, CT scan obtained
man with Increasing abdominal girth and palpable abdominal CT scan shows large lobulated mass with central necrosis
mass.
at lower level of mass shows small omental nodules (arrows). mass extended to greater curvature of stomach.
in left side
Fig. 2.-27-year-old of
trast-enhanced Supenoriy,
man with signs and symptract obstruction. Conaxial CT scan of 1-cm-thick section
toms of bowel and urinary
shows lobulated, septated, centrally necrotic mass that extended inferioriy from greater curvature stomach. A smaller polvic mass was the cause
hydronephrosis. A small focus of calcification was also noted on an unenhanced scan.
row)
of of (ar-
Downloaded from www.ajronline.org by 201.62.50.27 on 11/09/15 from IP address 201.62.50.27. Copyright ARRS. For personal use only; all rights reserved
AJA:158,
Fig.
CT OF ABDOMINAL
May 1992
3.-24-year-old
man
with
palpable
Fig. 5.-A, small
Low-power
photomicrograph
round
neoplasm
cell
shows
ROUND
CELL
TUMOR
1033
Fig. 4.-36-year-old man with tumor progression despite multidrug therapy. A, Contrast-enhanced CT scan shows liver metastases, lnteraortocaval retroperitoneal lymphadenopathy (large arrow), and abdominal implants (small arrow). B, CT scan obtaIned at superior aspect of liver shows anterior diaphragmatic lymphadenopathy (arrow) In addition to liver metastases.
pelvic
mass and enlarged left anterior cervical nodes. Contrast-enhanced CT scan shows large lobulated, centrally necrotic pelv’ic mass and dilated left ureter (arrow).
lignant
SMALL
of matumor
nest surrounded by dense stroma. (H and E, origInal magnification x120) B, Photomicrograph
of
immunocytochemical
preparation shows reactivity for keratin throughout cytoplasm of tumor cells. (Avidin-biotin-peroxidase complex stain, original magnification x300)
lymphoma, and neuroblastoma [2]. The most characteristic diagnostic feature of this tumor is the coexpression of epithehal (keratin) and mesenchymal types of intermediate filaments (desmin and vimentin). This unique immunophenotype, together with a marked predilection for young men, abdominopelvic location, and aggressive clinical behavior, supports the concept that malignant small round cell tumor of the abdomen represents a distinct clinicopathologic entity [1 2]. The exact cell of tumor origin is not known, but in most instances, it appears to arise from the peritoneum [1 2]. Experience in the treatment of malignant small round cell tumor of the abdomen is limited, and in our cases, no significant response was noted on multidrug chemotherapy regimens. The role of debulking surgery is yet to be determined. The peritoneum is more often involved by metastatic disease than it is the site of origin of primary neoplasms. The common malignant lesions that cause peritoneal carcinoma,
,
tosis are ovarian, colonic, and gastric carcinomas [9]. CT signs of peritoneal carcinomatosis include ascites, nodular peritoneal thickening, omental implants, and calcified peritoneal implants [9]. Nodular or masslike peritoneal involvement may also be seen in lymphoma, peritoneal leiomyosarcomatosis, and peritoneal mesothelioma [9-1 1 ]. Gastric leiomyosarcomas may be visualized on CT scanning as large necrotic exogastric masses extending into the abdominal cavity [12, 13]. The CT findings noted in our small series of patients with primary malignant small round cell tumor of the abdomen appear nonspecific and mimic findings noted in peritoneal carcinomatosis, leiomyosarcomatosis, and gastric leiomyosarcomas. Percutaneous fine-needle aspiration biopsy will probably be useful in the diagnosis of malignant small round cell tumor of the abdomen as pathologists become increasingly familiar with this entity. It is extremely important for
1034
VARMA
Downloaded from www.ajronline.org by 201.62.50.27 on 11/09/15 from IP address 201.62.50.27. Copyright ARRS. For personal use only; all rights reserved
radiologists to be aware of this newly described entity. This knowledge would help the radiologist to offer an appropriate differential diagnosis when multiple peritoneal masses are noted on abdominal CT scans, especially in young men.
REFERENCES 1 . Ordb#{241}ezNG, Zirkin A, Bloom RE. Malignant small-cell epithelial the peritoneum coexpressing mesenchymal-type intermediate Am J Surg Pathol 1989;13:413-421
2. Gerald WL, Miller HK, Battifora abdominal distinctive individuals.
tumor of filaments.
H, Mieltinen M, Silva EG, Rosai J. Intra-
desmoplastic small round-cell tumor: report of 1 9 cases of a type of high-grade polyphenotypic malignancy affecting young Am J Surg Pathol 1991;15:499-513
3. Variend 5, Gerrard M, Norris PD, Goepel JR. lntraabdorninal dermal tumour 1991;18:45-51
4. Gonzalez-Crussi
of childhood
with divergent
F, Crawford
plastic small cell tumors three cases of childhood.
SE, Chen-Chih
differentiation.
neuroecto-
Histopathology
JS. Intra-abdominal
desmo-
with divergent differentiation: observations Am J Surg Pathol 1990;14:633-642
on
New Format
ET AL.
AJR:158,
5. Hsu SM, Raine L, Fanger H. Use of avidin-biotin-peroxidase in immunoperoxidase
beled antibody
technique:
a comparison
(PAP) procedures.
J
between
Histochem
May 1992
complex (ABC) ABC and unla-
Cytochem
1981;29:
577-580
6. Ord#{244}hez NG, Manning
JT, Brooks
TE. Effect of trypsinization
on the
irnmunostaining of formalin-fixed, paraffin-embedded tissues. Am J Surg Pathol 1988;12:121-129 7. Unis EJ. Ewing’s sarcoma and related small round cell neoplasrns in children. Am J Surg Pathol 1986;10[suppl 1]:54-62 8. Triche TJ. Diagnosis of small round cell tumors of childhood. Bull Cancer
(Paris) 1988;75:297-310 9. Walkey MM, Friedman AC, Sohotra P, Radecki PD. CT manifestations pentoneal carcinornatosis. AJR 1988;150: 1035-1 041
of
10. Chol BI, Lee WJ, Chi JG, Han JK. CT manifestations of peritoneal Ieiomyosarcomatosis. AJR 1990;155:799-801 1 1 . Reuter K, Raptopoulos V, Reale F, et al. Diagnosis of peritoneal mesothelioma: computed tomography, sonography, and fine-needle aspiration biopsy. AJR 1983;140: 1189-1194 1 2. Nauert TC, Zomoza J, Ordonez N. Gastric Ieiomyosarcornas. AJR 1982;139:291 -297 13. McLeod IJ, Zornoza J, Shirkhoda A. Leiomyosarcorna: computed tomography findings. Radiology 1984;152: 133-1 36
for Abstracts
Beginning in Fall 1992, the AJR will publish abstracts of articles in a different format, much like the ones recently adopted by the New England Journal of Medicine and the Journal of the American MedicalAssociation. The purpose of the new design is to have abstracts present the essential elements of articles more clearly and concisely. The contents, organization, and length of the abstracts will be the same as before; however, rather than being all one paragraph except for the conclusion, abstracts will now be divided into four paragraphs, each with a title: objective, subjects (or materials) and methods, results, and conclusion. The AJR Guidelines for Authors, which appears at the front of every issue of the Journal, has been revised to help you write abstracts in this new format. Authors should familiarize themselves with these guidelines and incorporate them into all manuscripts submitted for publication.
Robert N. Berk Editor-in-Chief
1031
Primary Malignant Small Round Cell Tumor of the Abdomen: CT Findings
in Five Cases
Malignant small round cell tumor of the abdomen is a newly described clinicopathoDatla G. K. Varma1 logic entity. The features of this entity include a predilection for young men, predominant Kelvin McDaniel1 location, and aggressive behavior. Pathologic analysis demonstrates a Nelson G. Ord#{244}#{241}ez2 abdominopelvic small-cell tumor unusually coexpressing desmin and keratin. This study describes CT Christine A. J. Granfiel& characteristics in five patients with malignant small round cell tumor of the abdomen. Chusilp Charnsangavej1 All patients were young white men, 20-36 years old (mean, 28 years). In all five cases, Sidney Wallace1 CT
scans
surfaces
revealed
lobulated
and predominantly
and pelvis
(two cases);
masses were centrally iodinated
contrast
masses
appearing
the
involving
diffuse abdominopelvic necrotic and enhanced
material.
Additional
to arise
primarily from peritoneal of the abdomen (two cases) involvement was noted in one case. The inhomogeneously after administration of
peritoneal
cavity
CT features
included
ascites
(one case),
calcifi-
cations in the dominant mass (one case), omental implants (two cases), hydronephrosis (four cases), anterior diaphragmatic lymphadenopathy (two cases), liver metastases (two cases), and retroperitoneal lymphadenopathy (two cases). CT findings of abdominal malignant small round cell tumor are nonspecific and mimic findings noted in other conditions, such as pentoneal carcinomatosis and leiomyosarcomatosis. AJR
158:1031-1034,
May
1992
A distinctive type of malignant small round cell tumor of the abdomen has been recently described in the pathologic literature [1-4]. Unique features of this neoplasm include a predilection for young men, predominant location in the peritoneal cavity with a possible predilection for the pelvic region, and aggressive behavior with high mortality despite multiple modes of therapy [2]. Immunohistochemical studies are unique in this entity in that there is coexpression of keratin and desmin indicating the presence of epithelial and muscle-associated antigens [1 2]. To our knowledge, malignant small round cell tumor of the abdomen has not been previously reported in the radiologic literature. Abdominal CT findings in five patients with malignant small round cell tumor of the abdomen are the subject of this report. ,
Materials
and
We searched Received revision
November 13, 1991 December 16, 1991.
;
accepted
after
2
Department
of Pathology, Cancer
The
0361-803X/92/1 585-1031 CAmerican
Roentgen
University
of
Center, Houston, TX
77030. Ray SOciety
with
abdomen
I Department of Diagnostic Radiology, Box 57, The University of Texas M. D. Anderson Cancer Center, 1515 HOICOmbO Blvd., Houston, TX 77030. Address reprint requests to D. G. K. Varma.
Texas M. D. Anderson
patients
Methods
the consultation
malignant
and pelvis had
files of one of the authors
small
round
cell tumor
been
obtained.
and found the records
of the abdomen
in whom
The CT scans were reviewed
CT scans
retrospectively.
of five of the
All five
patients were young white men 20-36 years old (mean, 28 years). The patients had no clinical evidence of AIDS. Two patients tested negative for antibodies to HIV; the other patients were not tested. The patients had palpable abdominal and/or pelvic masses. One patient
also
had an enlarged
metastatic
left anterior
cervical
lymph
node.
Signs
and
symptoms
were related to mass effect on contiguous organs. Diagnosis was based on pathologic examination of tissue specimens obtained during exploratory laparotomy (four cases) and from a resected
cervical
lymph
was done by one of the authors,
node (one case).
The histopathologic diagnosis of this tumor small round cell tumor of the
who is familiar with malignant
1032
VARMA
abdomen
[1].
Immunohistochemical
studies
were
performed
in all
cases by using the avidin-biotin-peroxidase complex method [5]. The details of additional immunostaining procedures performed are de-
Downloaded from www.ajronline.org by 201.62.50.27 on 11/09/15 from IP address 201.62.50.27. Copyright ARRS. For personal use only; all rights reserved
scribed
elsewhere
[6]. Tissue
for electron
microscopy
studies
was
available in one case. CT scans were obtained with a GE 9800 scanner(General Electric, Milwaukee, WI) in three cases and with GE 8800 and Picker 1200 SX (Picker International, Highland Heights, OH) scanners in one case each. The scans consisted of contiguous 1 .0-cm-thick sections. In all patients scans were obtained after IV infusion of 150 ml of contrast material and with oral and rectal administration of diluted barium. In three
patients,
injector
IV contrast
material
was
administered
at 1 .5 mI/sec with a 60-sec delay; in
drip infusion
technique
was used.
two
In two patients,
AJR:158,
May 1992
tures included ascites (one case), omental implants (two cases), hydronephrosis (four cases), anterior diaphragmatic lymphadenopathy (two cases), liver metastases (two cases), and retroperitoneal lymphadenopathy (two cases)(Figs. 2 and 4). The hydronephrosis was caused by the pelvic masses impinging on the ureters; the masses also abutted loops of bowel causing symptoms of intermittent bowel obstruction.
Pathology
via power
patients,
a rapid
unenhanced
scans
were also obtained. The CT scans were analyzed for anatomic location of tumor, morphologic characteristics, extent of disease, and associated findings.
Results In all five cases, CT scans revealed lobulated masses appearing to arise from peritoneal surfaces and ranging in size from 5 x 4 cm to 1 5 x 8 cm. In two cases, the masses were located predominantly in the peritoneal cavity of the left abdomen extending inferiorly from the greater curvature of the stomach to the level of the lower pole of the kidneys (Figs. 1 and 2). The masses were centrally necrotic and enhanced inhomogeneously after administration of iodinated contrast material; one tumor demonstrated foci of calcification (Fig. 2). A smaller pelvic component posterior to the urinary bladder was also noted in one of these tumors. In two patients, large lobulated masses were identified in the pelvis posterior to the bladder and anterior to the rectum (Fig. 3), and one patient had diffuse abdominopelvic involvement. Additional CT fea-
A
ET AL.
Histologically, the five tumors were similar (Fig. 5). They were made up of well-defined, solid clusters of small tumor cells separated by dense fibrous stroma. The larger tumor nests had central necrosis, and mitotic figures were frequent. lmmunocytochemical studies demonstrated that the tumor cells stained with keratin in all cases; in addition to keratin, most tumor cells also reacted with desmin and vimentin. No reactivity for chromogranin A or S-i 00 protein was seen in any of the cases. The most striking ultrastructural feature was the presence of large amounts of intracytoplasmic intermediate filaments that often formed paranuclear bundles and whorls. No neuroendocrine granules were seen.
Discussion Malignant small round cell tumor of the abdomen appears to be a distinct clinicopathologic entity belonging to the generic category of small round cell tumors of infancy and childhood [2, 7, 8]. The category of small round cell tumors of infancy and childhood includes Ewing’s sarcoma, primitive neuroectodermal tumor, embryonal and rhabdomyosarcoma,
B Fig. 1.-32-year-old
A, Contrast-enhanced abdomen. B, CT scan obtained
man with Increasing abdominal girth and palpable abdominal CT scan shows large lobulated mass with central necrosis
mass.
at lower level of mass shows small omental nodules (arrows). mass extended to greater curvature of stomach.
in left side
Fig. 2.-27-year-old of
trast-enhanced Supenoriy,
man with signs and symptract obstruction. Conaxial CT scan of 1-cm-thick section
toms of bowel and urinary
shows lobulated, septated, centrally necrotic mass that extended inferioriy from greater curvature stomach. A smaller polvic mass was the cause
hydronephrosis. A small focus of calcification was also noted on an unenhanced scan.
row)
of of (ar-
Downloaded from www.ajronline.org by 201.62.50.27 on 11/09/15 from IP address 201.62.50.27. Copyright ARRS. For personal use only; all rights reserved
AJA:158,
Fig.
CT OF ABDOMINAL
May 1992
3.-24-year-old
man
with
palpable
Fig. 5.-A, small
Low-power
photomicrograph
round
neoplasm
cell
shows
ROUND
CELL
TUMOR
1033
Fig. 4.-36-year-old man with tumor progression despite multidrug therapy. A, Contrast-enhanced CT scan shows liver metastases, lnteraortocaval retroperitoneal lymphadenopathy (large arrow), and abdominal implants (small arrow). B, CT scan obtaIned at superior aspect of liver shows anterior diaphragmatic lymphadenopathy (arrow) In addition to liver metastases.
pelvic
mass and enlarged left anterior cervical nodes. Contrast-enhanced CT scan shows large lobulated, centrally necrotic pelv’ic mass and dilated left ureter (arrow).
lignant
SMALL
of matumor
nest surrounded by dense stroma. (H and E, origInal magnification x120) B, Photomicrograph
of
immunocytochemical
preparation shows reactivity for keratin throughout cytoplasm of tumor cells. (Avidin-biotin-peroxidase complex stain, original magnification x300)
lymphoma, and neuroblastoma [2]. The most characteristic diagnostic feature of this tumor is the coexpression of epithehal (keratin) and mesenchymal types of intermediate filaments (desmin and vimentin). This unique immunophenotype, together with a marked predilection for young men, abdominopelvic location, and aggressive clinical behavior, supports the concept that malignant small round cell tumor of the abdomen represents a distinct clinicopathologic entity [1 2]. The exact cell of tumor origin is not known, but in most instances, it appears to arise from the peritoneum [1 2]. Experience in the treatment of malignant small round cell tumor of the abdomen is limited, and in our cases, no significant response was noted on multidrug chemotherapy regimens. The role of debulking surgery is yet to be determined. The peritoneum is more often involved by metastatic disease than it is the site of origin of primary neoplasms. The common malignant lesions that cause peritoneal carcinoma,
,
tosis are ovarian, colonic, and gastric carcinomas [9]. CT signs of peritoneal carcinomatosis include ascites, nodular peritoneal thickening, omental implants, and calcified peritoneal implants [9]. Nodular or masslike peritoneal involvement may also be seen in lymphoma, peritoneal leiomyosarcomatosis, and peritoneal mesothelioma [9-1 1 ]. Gastric leiomyosarcomas may be visualized on CT scanning as large necrotic exogastric masses extending into the abdominal cavity [12, 13]. The CT findings noted in our small series of patients with primary malignant small round cell tumor of the abdomen appear nonspecific and mimic findings noted in peritoneal carcinomatosis, leiomyosarcomatosis, and gastric leiomyosarcomas. Percutaneous fine-needle aspiration biopsy will probably be useful in the diagnosis of malignant small round cell tumor of the abdomen as pathologists become increasingly familiar with this entity. It is extremely important for
1034
VARMA
Downloaded from www.ajronline.org by 201.62.50.27 on 11/09/15 from IP address 201.62.50.27. Copyright ARRS. For personal use only; all rights reserved
radiologists to be aware of this newly described entity. This knowledge would help the radiologist to offer an appropriate differential diagnosis when multiple peritoneal masses are noted on abdominal CT scans, especially in young men.
REFERENCES 1 . Ordb#{241}ezNG, Zirkin A, Bloom RE. Malignant small-cell epithelial the peritoneum coexpressing mesenchymal-type intermediate Am J Surg Pathol 1989;13:413-421
2. Gerald WL, Miller HK, Battifora abdominal distinctive individuals.
tumor of filaments.
H, Mieltinen M, Silva EG, Rosai J. Intra-
desmoplastic small round-cell tumor: report of 1 9 cases of a type of high-grade polyphenotypic malignancy affecting young Am J Surg Pathol 1991;15:499-513
3. Variend 5, Gerrard M, Norris PD, Goepel JR. lntraabdorninal dermal tumour 1991;18:45-51
4. Gonzalez-Crussi
of childhood
with divergent
F, Crawford
plastic small cell tumors three cases of childhood.
SE, Chen-Chih
differentiation.
neuroecto-
Histopathology
JS. Intra-abdominal
desmo-
with divergent differentiation: observations Am J Surg Pathol 1990;14:633-642
on
New Format
ET AL.
AJR:158,
5. Hsu SM, Raine L, Fanger H. Use of avidin-biotin-peroxidase in immunoperoxidase
beled antibody
technique:
a comparison
(PAP) procedures.
J
between
Histochem
May 1992
complex (ABC) ABC and unla-
Cytochem
1981;29:
577-580
6. Ord#{244}hez NG, Manning
JT, Brooks
TE. Effect of trypsinization
on the
irnmunostaining of formalin-fixed, paraffin-embedded tissues. Am J Surg Pathol 1988;12:121-129 7. Unis EJ. Ewing’s sarcoma and related small round cell neoplasrns in children. Am J Surg Pathol 1986;10[suppl 1]:54-62 8. Triche TJ. Diagnosis of small round cell tumors of childhood. Bull Cancer
(Paris) 1988;75:297-310 9. Walkey MM, Friedman AC, Sohotra P, Radecki PD. CT manifestations pentoneal carcinornatosis. AJR 1988;150: 1035-1 041
of
10. Chol BI, Lee WJ, Chi JG, Han JK. CT manifestations of peritoneal Ieiomyosarcomatosis. AJR 1990;155:799-801 1 1 . Reuter K, Raptopoulos V, Reale F, et al. Diagnosis of peritoneal mesothelioma: computed tomography, sonography, and fine-needle aspiration biopsy. AJR 1983;140: 1189-1194 1 2. Nauert TC, Zomoza J, Ordonez N. Gastric Ieiomyosarcornas. AJR 1982;139:291 -297 13. McLeod IJ, Zornoza J, Shirkhoda A. Leiomyosarcorna: computed tomography findings. Radiology 1984;152: 133-1 36
for Abstracts
Beginning in Fall 1992, the AJR will publish abstracts of articles in a different format, much like the ones recently adopted by the New England Journal of Medicine and the Journal of the American MedicalAssociation. The purpose of the new design is to have abstracts present the essential elements of articles more clearly and concisely. The contents, organization, and length of the abstracts will be the same as before; however, rather than being all one paragraph except for the conclusion, abstracts will now be divided into four paragraphs, each with a title: objective, subjects (or materials) and methods, results, and conclusion. The AJR Guidelines for Authors, which appears at the front of every issue of the Journal, has been revised to help you write abstracts in this new format. Authors should familiarize themselves with these guidelines and incorporate them into all manuscripts submitted for publication.
Robert N. Berk Editor-in-Chief
