CARCINOMA OF BREAST AND PAGET'S DISEASE OF NIPPLE
A 79 year old woman gave a history of a lump in the left breast which she first noticed 6 months earlier. The lump had slowly enlarged and there had been an occasional blood-stained discharge from the nipple. On examination the nipple was raised and protuberant, the areola was reddened, crusted and nodular, and deep to the nipple there was a hard, irregular palpable mass. Axillary lymph nodes were not enlarged. A simple mastectomy was performed.
The breast has been sliced vertically through the nipple and both halves mounted to display the external and cut surfaces. The nipple appears distorted and the surface of the areolar is irregular and polypoid. On the cut surface there is a pale brown tumour 40 x 25 mm in diameter which is continuous with the nipple, areola and adjacent skin. The deep margin of the tumour is irregular but well demarcated from the surrounding white breast tissue and orange-yellow adipose tissue. At the margin of the tumour, there is a cyst 8 mm in diameter which is probably a dilated duct. This is an example of a carcinoma of the breast and Paget's disease of the nipple.
Paget's disease of the nipple is due to invasion of the epidermis by malignant cells which have spread to the skin of the nipple and areola from an underlying ductal carcinoma of the breast. The associated carcinoma arises in the main excretory ducts deep to the nipple and may be either intra-ductal or infiltrating. The tumour cells probably reach the epidermis by extension along the walls of the lactiferous ducts. In Paget's disease there are eczematous changes in the skin of the nipple and areola. Affected skin is red, crusted and fissured. Frequently there is no clinically palpable mass deep to the nipple. Approximately one-third of patients with Paget's disease of the nipple have metastases at the time of surgery.