| Epithelial
marker-negative desmoplastic small round cell tumor with atypical
morphology: definitive classification by fluorescence in situ
hybridization.Arch
Pathol Lab Med. 2007 Apr;131(4): 646-9.
Desmoplastic
small round cell tumor typically presents with abundant desmoplastic
stroma containing nested primitive round cells bearing a
polyphenotypic immunohistochemical profile. Lesions with minimal
classic morphology pose a formidable diagnostic challenge. The current
case represents one such example, arising as a large abdominal-pelvic
mass in a 17-year-old female patient. The tumor was composed of a
monomorphous population of small round cells lining microcystic
structures and forming pseudoacini and fine anastomosing trabeculae
and cords. The stroma was abundantly myxoid with only occasional thick
desmoplastic septa. The tumor cells were variably immunopositive for
vimentin, desmin, smooth muscle actin, synaptophysin, neuron-specific
enolase, Bcl-2 and WT1 (nuclear); epithelial markers were negative.
The definitive diagnosis of desmoplastic small round cell tumor was
rendered with the demonstration of the characteristic EWS-WT1 gene
fusion by fluorescence in situ hybridization. The current case
emphasizes the utility of fluorescence in situ hybridization to
demonstrate EWS-WT1 gene fusion in desmoplastic small round cell tumor
with nonclassic morphologic and immunohistochemical features to avoid
potential misdiagnosis. |
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Desmoplastic small round cell
tumour
Visit: Soft Tissue Pathology
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Desmoplastic small round cell tumor of the abdomen:
radiologic-histopathologic correlation.
Radiology.
1999 Mar;210(3):633-8.
PURPOSE: To
characterize the imaging features of desmoplastic small round cell
tumor of the abdomen and correlate them with the histopathologic
findings. MATERIALS AND METHODS: Eleven of 14 patients with
desmoplastic small round cell tumor had primary abdominal
involvement. In nine of these patients (mean age, 20 years), results
of imaging studies (computed tomography in nine patients,
ultrasonography [US] in three) and histopathologic specimens were
retrospectively analyzed. RESULTS: The hallmark imaging feature was
lobulated peritoneal masses (mean number, 4.4; range, 1-17) with a
mean diameter of 5.0 cm (range, 2-12 cm). Omental and paravesical
tumors were each present in six patients. Retroperitoneal masses
were present in three patients. The tumors were well defined and
hypoechoic at US. Heterogeneity due to tumor hemorrhage or necrosis
was seen in seven patients. Ascites was present in five patients.
Parenchymal and/or serosal hepatic metastases, punctate
calcifications, nodular peritoneal thickening, lymphadenopathy,
hydronephrosis, and bowel obstruction were less common associated
findings. CONCLUSION: Bulky peritoneal soft-tissue masses without an
apparent organ-based primary site are characteristic of
intraabdominal desmoplastic small round cell tumor. Although the
findings are nonspecific, this diagnosis can be considered in
adolescents and young adults with characteristic imaging findings.
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February 2008
Myxoid
Tumours of Soft Tissue
Classification
of Soft Tissue Tumour
Gross examination of soft tissue specimen |
