Fine-needle aspiration of adult rhabdomyoma: a case report with review of the literature.

The cytologic features of adult rhabdomyoma, a rare benign tumor of skeletal muscle origin, have been infrequently reported in the literature. We present here a case of a rhabdomyoma involving the floor of the mouth of a 78-year-old man initially diagnosed by fine-needle aspiration cytology. Cytologic features seen on Papanicolaou-stained smear preparation included cohesive clusters of skeletal muscle cells having abundant eosinophilic cytoplasm and often peripherally located nuclei. Although cross-striations and elongated intracytoplasmic inclusions were not identified in the smears, they were noted in the cell block preparation of the aspirated specimen and in the touch preparation and histologic sections of the surgically resected specimen. The cytologic differential diagnosis of this tumor is discussed.