Adenomyoepithelioma of the breast. A report of three cases and review of the literature.

Three adenomyoepitheliomas of the breast that occurred in elderly women are reported and the features of the six previously reported cases are reviewed. The tumors were characterized by a proliferation of glands lined by a dual population of cells. On the basis of their appearance in rountinely stained sections and their immunohistochemical features, the inner cells were interpreted as epithelial, whereas the cells of the outer layer, which typically had abundant, clear cytoplasm, were interpreted as myoepithelial. One tumor was associated with, and may have arisen from, an adenomyoepithelial type of adenosis. Despite relatively bland cytologic features, one lesion recurred three times over the course of seven years. Follow-up for the other two patients is of short duration. Because of the possibility of local recurrence, wide local excision is recommended.