Mammary carcinoma arising in ectopic breast tissue is an uncommon occurrence. Most reported cases have involved ductal carcinoma, but other types, such as medullary, papillary, and lobular carcinomas, have been described. For pathologists, the diagnosis of mammary carcinoma arising in ectopic breast tissue can be difficult, especially in the axilla, where carcinoma of adnexal origin must be excluded. We describe a 46-year-old woman who developed invasive (juvenile) secretory carcinoma in ectopic right axillary breast tissue and micrometastatic carcinoma in an ipsilateral axillary lymph node. The carcinoma arose in a right axillary mass that had been present for 8 years, from which she had secreted fluid during prior breast-feeding. To our knowledge, this is the first report of secretory carcinoma arising in axillary breast tissue to be documented in the current literature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.