title: Primary malignant small round cell tumor of the abdomen: CT findings in five cases.
abstract: Malignant small round cell tumor of the abdomen is a newly described clinicopathologic entity. The features of this entity include a predilection for young men, predominant abdominopelvic location, and aggressive behavior. Pathologic analysis demonstrates a small-cell tumor unusually coexpressing desmin and keratin. This study describes CT characteristics in five patients with malignant small round cell tumor of the abdomen. All patients were young white men, 20-36 years old (mean, 28 years). In all five cases, CT scans revealed lobulated masses appearing to arise primarily from peritoneal surfaces and predominantly involving the peritoneal cavity of the abdomen (two cases) and pelvis (two cases); diffuse abdominopelvic involvement was noted in one case. The masses were centrally necrotic and enhanced inhomogeneously after administration of iodinated contrast material. Additional CT features included ascites (one case), calcifications 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 peritoneal carcinomatosis and leiomyosarcomatosis.
authors.affiliation: Department of Diagnostic Radiology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
authors.forename: D G
authors.initials: DG
authors.lastname: Varma
authors.forename: K
authors.initials: K
authors.lastname: McDaniel
authors.forename: N G
authors.initials: NG
authors.lastname: Ordóñez
authors.forename: C A
authors.initials: CA
authors.lastname: Granfield
authors.forename: C
authors.initials: C
authors.lastname: Charnsangavej
authors.forename: S
authors.initials: S
authors.lastname: Wallace
mesh_terms: D000008:Abdominal Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000648:ultrastructure; D000328:Adult; D006801:Humans; D007124:Immunoenzyme Techniques; D007382:Intermediate Filaments / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D014057:Tomography, X-Ray Computed