Syringomatous adenoma of the nipple: a case report

Sir, Nipple tumours are uncommon lesions of the breast. Adenoma of the nipple, syringomatous adenoma and papilloma are the limited tumours involving the nipple and areolar region. Syringomatous adenoma of the nipple is a rare neoplasm, first described by Rosen in 1983. To date, less than 25 cases have been reported in the English literature. It differs from other tumours of the nipple and areolar region in being of skin appendageal origin and differentiation. Incomplete excision of this locally infiltrative tumour is associated with a high rate of recurrence. Nipple sacrifice may be necessary for achieving complete excision and histologically negative margins. To the best of our knowledge, this is the first case to be reported from India. A 20-year-old female presented with a 2-month history of an itchy nipple lump in her right breast. She also complained of one episode of serous nipple discharge. There was no history of bleeding from the nipple, anorexia or weight loss. On examination, the lump was causing nipple enlargement. The overlying skin was ulcerated. The ipsilateral axilla, contralateral breast and axilla were unremarkable. The mass was excised completely with wide margins, including the overlying skin. The surgical specimen was fixed in 10% neutral buffered formalin and paraffin embedded. Four-mm thick sections were cut and stained with H&E. Immunohistochemical staining for epithelial membrane antigen (M 0613, dilution 1:100; Dako, Sweden) and S100 (N 1573, Dako) was performed using the streptavidin–biotin–peroxidase technique. Appropriate positive and negative controls were prepared simultaneously. The gross specimen consisted of a skin-covered nodular soft tissue piece measuring 1 cm in maximum dimension. The surface showed foci of ulceration. Microscopically, a connection between the tumour and overlying skin was present. The epidermis was slightly hyperplastic. An area of ulceration was also seen. Keratotic cysts containing amorphous pink material were present in the superficial portion of the tumour (Fig. 1). The tumour was composed of ducts and tubules scattered in a fibrous stroma. Characteristic commaor tadpole-shaped ducts were seen. The majority of the ducts were lined with doublelayered epithelial cells. A few areas showed epithelial hyperplasia in the form of multilayering and micropapillae. Some ducts were slightly dilated and contained eosinophilic secretions and foamy cells. Lining cells were small, cuboidal, and contained a moderate amount of eosinophilic cytoplasm and central nuclei. Mitotic figures (five to six per 10 high power fields) were seen. Myoepithelial cells were inconspicuous. The stroma was fibrous and unremarkable. Lymphocytes and plasma cells were present in the stroma. There were no areas of haemorrhage or necrosis. At the periphery, the tumour infiltrated into the surrounding smooth muscle of the nipple and underlying breast parenchyma. In the deeper portion, tumour ducts surrounded lactiferous ducts (Fig. 2). The deep resected margin was free of tumour. Staining for epithelial membrane antigen showed positivity limited to the luminal border of epithelial cells. S100 stained tumour-infiltrating Langerhans cells, leaving epithelial cells unstained (Fig. 3). Myoepithelial cells were conspicuously absent. Syringomatous adenoma of the nipple is a rare neoplasm. Its morphological features, namely tadpoleshaped ducts embedded in a fibrous stroma and keratotic cysts, are strikingly similar to syringoma of the skin. However, syringomatous adenoma of the nipple is a locally infiltrating neoplasm, often involving the smooth muscle of the nipple, underlying breast parenchyma and even nerves. Our case showed all the typical morphological features of syringomatous adenoma of the nipple, including origin from overlying epidermis, keratotic cysts and local infiltration. In addition, our case showed uncommon features like epithelial hyperplasia and Fig. 1 Scanner view of tumour showing connection between the tumour and overlying skin. Keratotic cysts are seen in the upper left quadrant (H&E, original magnification, 640).