Characteristic imaging features of desmoplastic small round cell tumour.

Overview

BACKGROUND: Desmoplastic small round cell tumour (DSRCT) is a rare malignant neoplasm. Its radiological features have rarely been described. OBJECTIVE: To assess the CT parameters characteristic of DSRCT. We also report our experience with combined FDG PET/CT in staging and follow-up for DSRCT. MATERIALS AND METHODS: The pretreatment diagnostic CT's of 65 patients with DSRCT were evaluated. Pertinent imaging findings were catalogued, with histopathology or serial follow-up studies as reference standard. Combined FDG PET/CT examinations of 11 of these patients who underwent pretreatment imaging were also reviewed. RESULTS: Sixty-two patients presented with primary intra-abdominal disease; three had primary extra-abdominal tumours at presentation. The most common imaging finding of patients with intra-abdominal DSRCT was multiple peritoneal soft tissue masses, with a dominant mass in the retrovesical or rectouterine location in more than half of the cases. Forty percent had metastatic disease to the liver, lungs, spleen or bones at diagnosis. FDG PET/CT accurately detected 97.4% of all DSRCT lesions. CONCLUSION: DSRCT typically presents as a large abdominopelvic mass with widespread peritoneal involvement predominantly in young males. Familiarity with its radiological features can help guide diagnosis and treatment. Functional imaging with PET/CT offers advantage over anatomical imaging for accurate disease staging.