Aspiration cytology of proliferative myositis. A case report.

A case of proliferative myositis (PM) diagnosed by fine needle aspiration biopsy (FNAB) is described. A 72-year-old, white male presented with a 3.0-cm, firm, nontender mass involving the right sternocleidomastoid muscle. FNAB showed loose clusters of uniform, fibroblastlike spindle cells and admixed large, ganglion cell-like cells with eccentric nuclei, prominent nucleoli and abundant cytoplasm. The cytologic appearance of PM is characteristic, allowing exclusion of malignancy; reliable FNAB diagnosis when supported by clinical findings; and avoidance of unnecessary, radical surgery.