Mixed apocrine/endocrine ductal carcinoma in situ of the breast coexistent with lobular carcinoma in situ

摘要

An unusual mixed form of ductal carci- noma in situ (DCIS) of the breast is described, which exhibits a biphenotypic morphoogy encompassing a range of dif- ferential diagnostic DCIS subtypes. In addition, immnophenotypic and ul- trastructural studies demonstrate neu- roendocrine and aprocrine differentiation, raising questions regarding appropriate classification and biological behaviour. In two cases, coexistence of this mixed form of DCIS with lobular carcinoma in situ (LCS) in the same duct lobular units is an additional unusual feature that might, at least in some cases, indicate a closer real- tion between them.