Korean J Intern Med.  2012 Mar;27(1):91-94. 10.3904/kjim.2012.27.1.91.

Ewing's Sarcoma of the Lesser Sac Masquerading as a Pancreatic Tumor

• Rao L
• Monappa V
• Rodrigues
• Suresh BP

• KMID: 1776571
• DOI: http://doi.org/10.3904/kjim.2012.27.1.91

Abstract

Extraosseous Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) is an uncommon, aggressive, and malignant tumor with a poor patient outcome. Its occurrence in the lesser sac is a rare event and to the best of our knowledge, has not been previously described. The present case was clinically and radiologically misdiagnosed as a pancreatic tumor/gastrointestinal stromal tumor. Histopathology revealed a tumor with "small round cells" that were positive for CD99, confirming the diagnosis of ES/PNET. This report highlights the importance of considering Ewing's sarcoma in the differential diagnosis of intraabdominal, extraintestinal masses.

Keyword

CD99 protein; Sarcoma, Ewing; Extraosseous; Neuroectodermal tumors, primitive

MeSH Terms

Antigens, CD/analysis
Biopsy
Cell Adhesion Molecules/analysis
*Diagnostic Errors
Female
Humans
Immunohistochemistry
Middle Aged
Neuroectodermal Tumors, Primitive, Peripheral/*diagnosis/immunology/pathology/therapy
Pancreatic Neoplasms/*diagnosis
Peritoneal Neoplasms/*diagnosis/immunology/pathology/therapy
Predictive Value of Tests
Sarcoma, Ewing/*diagnosis/immunology/pathology/therapy
Tomography, X-Ray Computed
Tumor Markers, Biological/analysis