Spiradenocarcinoma of the breast arising in a long-standing spiradenoma.

The embryologic origin of the breast is related to salivary and sweats glands. Thus, breast neoplasms may show differentiation toward these tissues, although this is a rare event in humans. We report the clinicopathologic and immunohistochemical features of a 57-year-old woman presenting with a spiradenoma that originated in breast tissue and became malignant 40 years later. Some histogenetic concepts relevant to this case are discussed, along with a brief review of this neoplasm.