Intraabdominal desmoplastic small round cell tumor - Report of a case withfine needle aspiration, cytologic diagnosis and molecular confirmation

BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is a recently descr ibed neoplasm. This entity is well defined, with distinct clinical, patholo gic and immunohistochemical features. Molecular studies have shown a specif ic reciprocal translocation t(11;22)(p13;q12). To our knowledge, no report of DSRCT with molecular confirmation on cytological material has been repor ted before. CASE: Fine needle aspiration (FNA) was performed on an intraabdominal mass in a 37-year-old man. A May-Grunwald-Giemsa-stained preparation showed clus ters of small round tumor cells associated with desmoplastic stromal cells, highly suggestive of DSRCT. FNA of a supraclavicular node showed cytologic features similar to those of the primary abdominal mass, including a promi nent desmoplastic reaction of the stroma. Immunocytochemical studies showed myogenic and epithelial differentiation. Molecular analysis was performed on FNA, revealing the EWS/WT1 chimeric transcript and thus confirming the c ytologic diagnosis. CONCLUSION: Cytomorphologically, a definitive diagnosis of DSRCT may be dif ficult, as this tumor bears considerable resemblance to other small round c ell tumors. The diagnosis can be confirmed by ancillary techniques, such as immunocytochemistry, adn particularly by molecular analysis, which may als o be performed on cytologic material.