Fine-needle aspiration cytology of spindle-cell argyrophilic mucin-producing carcinoma of the breast.

An unusual breast carcinoma with prominent spindle cells, intracytoplasmic mucin, and argyrophilia in an 82-yr-old woman was sampled preoperatively by fine-needle aspiration (FNA). The smears contained highly cellular sheets and fragments of uniform spindle cells with abundant vacuolated cytoplasm. The cells were mucicarmine positive and contained many cytoplasmic argyrophilic granules. The findings were confirmed by histologic examination of the excised tumor, which was also studied with a panel of immunohistochemical stains. A review of the literature indicated that spindle-cell argyrophilic mucin-producing carcinoma (SCAMPC) of the breast is a very rare neoplasm presenting primarily in elderly patients. The FNA cytologic features seem to be unique and should allow distinction from other primary breast lesions.