ThinPrep Cytological Findings of Desmoplastic Small Round Cell Tumor with Extensive Glandular Differentiation: A Case Study

Desmoplastic small round cell tumor (DSRCT) is a rare and highly aggressive neoplasm. The cytological diagnosis of this tumor has only been reported in a few cases. In most of these cases, the diagnosis was made using fine-needle aspiration cytology. Most DSRCTs resemble disseminated carcinomatoses in their clinical manifestation as well as cytomorphologically, even in young-adult patients. These authors report a case of using peritoneal-washing and pleural-effusion ThinPrep cytology to diagnose DSRCT, with extensive glandular differentiation and mucin vacuoles. We found that fibrillary stromal fragment, clinical setting, and adjunctive immunocytochemical staining were most helpful for avoiding misdiagnosis.