Presentation
Abdominal sweling.
Patient Data
FDG avid large intra-abdominal left hypochondrial soft tissue mass lesion with SUV max 12. The mass is indenting the transverse colon and is abutting the adjacent chest wall. A small supra-diaphragmatic extension into the left epicardial fat is noted. The lesion is heterogeneous showing internal cystic changes.
FDG avid left internal mammary lymph node.
Findings are suggestive of left hypochondria peritoneal neoplastic mass (possible sarcoma), associated with metastatic left internal mammary lymph node.
Case Discussion
Desmoplastic small round cell tumor (DSRCT) is a member of the family of small round blue cell tumors. It is common in adolescent male patients. Patients usually present with abdominal pain or swelling. It is a rare and very aggressive mesenchymal neoplasm that grows along the peritoneal surfaces.
Imaging features include solitary or multiple soft tissue masses arising from the peritoneum, omentum, or mesentery without a definite organ of origin.
Appearances carry a differential diagnosis, as it cannot be differentiated from other malignant peritoneal tumors such as mesothelioma, rhabdomyosarcoma, lymphoma, desmoid, or neuroblastoma on imaging alone.