Primary abdominopelvic desmoplastic small round cell tumor: CT and correlated clinicopathologic features

To evaluate the CT characteristics of primary abdominopelvic desmoplastic small round cell tumor (DSCRT) and investigate the relation between radiologic features and corresponding clinicopathologic features.

A cohort study was performed on 12 abdominopelvic DSCRT patients, the preoperative computed tomography (CT) and contrast enhancement CT scan were performed in all cases. Tumor dimension, location, calcification, organs involvement, metastasis and enhancement characteristics were retrospectively evaluated and catalogued. Histopathology and serial immunological histological chemistry (IHC) studies were as diagnostic reference standard, all clinicopathological and radiological data were analyzed with emphasis on the corresponding imaging findings.

Abdominopelvic DSRCT mainly affects young males (male to female was 2:1), Predominantly, two individualized CT subtype patterns were noted according to its characteristic features and the most common imaging findings are extensively disseminated masses in the peritoneal cavity and/or mesentery with slight enhancement after administration of contrast (subtype 1, 9/12; 75%), the type was in correlated with the histopathologic findings of a large stromal component and scare of vessels or tumor cells. In subtype 2 (3/12; 25%), the tumor was solitary and bulky soft-tissue mass localized in retroperitoneum or retrovesical space, it manifested as heterogeneous enhancement which correlated well with the presence of abundance of microvessels and tumor cells.

Radiologically, abdomino-pelvic DSRCT is lack of pathognomonic CT character, the most common CT finding is multiple soft tissue masses or solitary bulky lesion inclined to extensively peritoneal and mesenteric spread with heterogeneous enhancement. These radiological findings are related to different histological compositions, awareness of these radiological features may facilitate the CT diagnosis.