Syringomatous adenoma of the nipple.

A benign, locally infiltrating tumor histologically similar to syringoma of skin adnexal origin has been found in the nipple in five patients. Four women were 28-41 years of age (mean 36 years) and a man was 76 years old. The lesion was solitary and unilateral in each case. Grossly, minute cystic areas were noted in some specimens. Microscopically, typical tubular, duct-like structures and keratinizing cysts were present throughout the lesion. Follow-up is available for four patients. Two were free of recurrence 2 and 2.5 years after nipple resection. A third patient treated by mastectomy 3 years ago is also disease-free. In a fourth woman, the lesion persisted and slowly enlarged over 22 years after incomplete excision. Eventually partial mastectomy was required and she died of colonic carcinoma 2 years later. Syringomatous adenoma is a morphologically characteristic neoplasm that can be distinguished from florid papillomatosis of nipple ducts; it is capable of local invasion and recurrence if not completely excised. Adequate treatment may require nipple resection.