FINE-NEEDLE ASPIRATION BIOPSY OF CHILDHOOD RHABDOMYOSARCOMA - REEVALUATION OF THE CYTOLOGIC CRITERIA FOR DIAGNOSIS

The distinction between rhabdomyosarcoma (RMS) and the other small rou nd blue cell rumors of childhood has therapeutic implications which st ress the importance of a correct diagnosis. In attempts to reevaluate the cytologic criteria of this entity, we reviewed a series of 17 fine -needle aspiration biopsies and three touch imprints from soft tissue masses. AN cases had been histologically confirmed except for two case s that only had immunocytochemical and ultrastructural confirmation. T he features occurring most commonly include a uniform population of tu mor cells arranged as single cells and cohesive aggregates. The cells were predominantly round/polygonal, with uniform nuclei and scant to m oderate amounts of cytoplasm. The nuclear chromatin was most often fin ely granular and hyperchromatic, while nucleoli were inconspicuous. Bi nucleated and multinucleated cells were found in 17 of the 20 smears. Intracytoplasmic vacuoles were present in 17 cases, ranging from occas ional in one case, a few in IO cases, and very numerous in six cases. We conclude that the presence of bi/multinucleated cells is an importa nt clue for the diagnosis of RMS on fine-needle aspiration biopsy. (C) 1994 Wiley-Liss, Inc.