Purpose or Case Report: Desmoplastic small round cell tumor (DSRCT) is a rare, aggressive sarcoma of the Ewing’s sarcoma family with the presence of EWSR1 gene mutation. It predominantly affects adolescent males. DSRCT typically arises from peritoneal or pelvic serosal surfaces and often presents at an advanced stage. Because symptoms are vague, imaging plays a crucial role in early recognition. We review the CECT findings of pediatric patients of DSRCT who were managed at our institute.
Methods & Materials: We conducted a retrospective review of the cross-sectional imaging of 14 patients diagnosed with DSRCT over the last decade, with the baseline imaging available in 9 patients and follow-up imaging available in all 14 patients. A consensus review was performed by two dedicated oncoradiologists based on image review on institutional PACS. Clinical information was obtained from electronic medical records, with the histology confirmed by a dedicated oncopathologist in all cases.
Results: The study included 14 patients, all males. The mean age of presentation was 17 years (range 5-18 years). All the 9 patients with baseline imaging available presented with lobulated abdominopelvic masses, demonstrating relatively homogeneous (3/9) or heterogeneous (6/9) contrast enhancement. A single patient presented with a solitary left upper quadrant mass, 4/9 (45%) had 2-5 peritoneal lesions, and 4/9 (45%) had >5 lesions. A dominant mass was seen in 4/9 (45%) patients, with the rest had multiple relatively equal sized masses without a dominant lesion. 8/9 (89%) patients had solid masses (>75% solid component), while one patient had solid-cystic/necrotic lesion. No organ of origin was identifiable in any patient. Calcifications were present in h 4/9 (45%) cases. Overall, all 14 patients demonstrated recurrent/ metastatic disease, with multifocal peritoneal recurrence, with similar imaging findings as described above. 5/14 (35%) patients also demonstrated associated metastatic nodal involvement (3 retroperitoneal, one pelvic and one epicardiac), 4/14 (28%) had liver metastases and one had lung metastases. At the time of last follow-up, two patients had expired, three were lost to follow-up, while the remaining 8 were alive, albeit only 1/14 was disease-free.
Conclusions: DSRCT presented with diffuse peritoneal involvement and large soft tissue masses without a definite organ of origin. Nodal and hepatic involvement was seen at the time of recurrence in 35% and 28% patients respectively.