Syringomatous Adenoma of the Nipple with Associated Invasive Carcinoma: A Case Report.

Syringomatous adenoma of the nipple is a rare benign infiltrative neoplasm that was first described in 1983. At the time of this writing, a literature search revealed no cases of syringomatous adenoma of the nipple in association with invasive carcinoma of the breast. We report a case of syringomatous adenoma of the nipple in a 40-year old female who also had bilateral invasive ductal carcinoma and ductal carcinoma in situ of the breasts. Syringomatous adenomas of the nipple have been postulated to originate from eccrine structures of the nipple due to their microscopic similarity to other tumors of eccrine origin, such as syringomatous carcinoma. However, their exact origin is uncertain. Despite their benign behavior, they usually demonstrate an infiltrative and expansile proliferation into adjacent nipple and breast tissue. They have been confused with tubular carcinoma and low-grade adenosquamous carcinoma of the breast, both clinically and histologically. Complete excision is the therapy of choice, and only incompletely excised lesions have shown recurrence. We present this case to raise awareness that syringomatous adenoma of the nipple may present in patients with a simultaneous invasive carcinoma of the breast.