FINE-NEEDLE ASPIRATION OF INTRAABDOMINAL DESMOPLASTIC SMALL-CELL TUMOR

The cytologic features of four cases of histologically confirmed intra -abdominal desmoplastic small cell tumor (DSCT) that occurred in males between 18-27 yr of age are presented Smears showed small cells with scant cytoplasm which were primarily arranged in loosely cohesive clus ters. Nuclei were oval to round with evenly distributed, finely granul ar chromatin and inconspicuous nucleoli. As is typical of DSCT, the ce lls strongly expressed keratin and desmin in all cases. In the one cas e studied by electron microscopy, it was demonstrated that the cells w ere joined by small junctions and contained paranuclear aggregates of intermediate filaments. The absence of the characteristic desmoplastic stroma in DSCT aspirates and the nonspecific cytologic features of th is small round-cell tumor (SRCT) made cytologic interpretation difficu lt. Cytopathologists should be aware of this entity so that DSCT is in cluded in the differential diagnosis of SRCTs that occur in intra-abdo minal sites. A panel of markers that includes keratin and desmin shoul d be used to assist in the identification of DSCT. (C) 1993 Wiley-Liss , Inc.