SMALL ROUND-CELL TUMOR WITH DIVERGENT DIFFERENTIATION - CYTOLOGIC, HISTOLOGIC, AND ULTRASTRUCTURAL FINDINGS

A case study of desmoplastic small round cell tumor with divergent dif ferentiation in a 13-yr-old boy is presented Clinical, cytologic, hist ologic, immunohistochemical, and ultrastructural findings are reported . There was a close correlation between the various histologic and cyt ologic patterns. Immunohistochemical studies revealed strong positivit y of many of the tumor cells for cytokeratin, vimentin, and desmin. Ul trastructurally, some of the tumor cells contained aggregates of cytop lasmic intermediate filaments. Fine-needle aspiration biopsy may sugge st the diagnosis of desmoplastic small round cell tumor. Confirmation of the diagnosis may be provided by immuhistochemistry and electronmic roscopy. (C) 1994 Wiley-Liss, Inc.