Intra-abdominal desmoplastic small round cell tumors:CT findings and pathological correlations in 8 cases

Objective:To investigate the CT findings in desmoplastic small round cell tumors(DSRCT).Methods:8 cases with pathologically proved hepatic DSRCT underwent plain and enhanced CT scans,the imaging features were analysed retrospectively and their correlations with pathology were studied.Results:All 8 cases of DSRCT demonstrated solitary lesions(n=5) or multiple irregular masses(n=5).The main sites of peritoneal involvement were the pelvic space(n=5) and omentum(n=5).CT showed lobulated or nodular masses with heterogeneous hypodensity in the abdominopelvic spaces.Intratumoral necrosis(n=3) and calcifications(n=4) could be noted.On contrast enhanced CT scan,all lesions revealed heterogeneous enhancement.The mean CT attenuation values of the tumors at precontrast phase,arterial phase and portal phase were 38.9HU,56.1HU and 62.5HU respectively.Microscopic analysis of all 8 cases demonstrated clumps of small round cells with hyperchromatic nuclei and small eosinophilic cytoplasm,surrounded by a hypocellular desmoplastic,collagenous stroma.Three of them showed intratumoral necrosis.Conclusion:There are certain relations between spiral CT appearance and histopathology in DSRCT.CT Imaging is useful for diagnosis of DSRCT and its staging and also for guiding biopsies.