Fine needle aspiration of proliferative fasciitis. A case report.

The cytologic findings of a fine needle aspiration (FNA) biopsy from a patient with proliferative fasciitis, a benign, reactive process involving the subcutaneous tissue, are presented. Proliferative fasciitis is defined histologically as a spindle-cell lesion containing basophilic giant cells that resemble ganglion cells; the FNA smears from this patient's lesion were cellular and contained spindle cells as well as numerous large cells with abundant cytoplasm, one to two eccentric nuclei and macronucleoli. The large cells seen on the aspiration smears correspond well with the classic ganglionlike cells seen on histologic sections. Care must be taken so that this distinctive lesion is not misdiagnosed as a malignant soft tissue neoplasm.