Nipple adenoma arising from axillary accessory breast: a case report

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1186821489769063 webciteNipple adenoma is a benign proliferative lesion of the breast that arises from galactophorous duct of the nipple. It was first recognized as a distinctive entity in 1955 by Jones who referred to it as “florid papillomatosis” of the nipple duct [1]. Nipple adenoma, also known as nipple duct adenoma, papillary adenoma, erosive adenomatosis, florid papillomatosis, papillomatosis of the nipple and subareolar duct papillomatosis, is a variant of intraductal papilloma involving the terminal portion of the galactophorous ducts [2-5]. Clinically, nipple adenoma can be mistaken for Paget’s disease and can be interpreted pathologically as a tubular carcinoma. Although axillary tumors have many differential diagnoses ranging from benign to malignant, nipple adenoma arising from the axillary accessory breast has rarely been described in the English literature. We describe the clinical and pathological finding relating to a rare case of nipple adenoma arising in an axillary accessory breast.An 82-year-old Japanese woman presented with the complaint of a painful tumor that had been localized in the right axilla. The tumor was a well-circumscribed eczematous crusted tumor with erythema that was 8 mm in size, and exhibited erosion but no discharge (Figure 1). The tumor was separate from the patient’s breast and the axillary lymph nodes were not palpable. It was suspected as being an inflamed epidermal cyst, furuncle or possibly extramammary Paget’s disease. No neoplastic lesions were detected in the patient’s breast. Complete local excision was performed under local anesthesia. Histologically, the tumor was diagnosed as nipple adenoma arising from the axillary accessory breast. The patient has had no local recurrence at 2 years after excision of the tumor.In cross section the tumor was 8 mm in diameter, appeared non-encapsulated and firm, and had no continu