[Adenoma of the nipple with malignant degeneration]

A rare nipple tumor observed in a 75-year-old woman is reported. The tumor was initially diagnosed on morphologic criteria as a nipple adenoma, but detailed examination of a segmental resection specimen revealed areas of malignant change resembling intraduct cancer. The patient underwent amputation of the mammary gland, and examination of the operative specimen demonstrated microfoci of invasive growth into lymphatic clefts.