Mammary endocrine ductal carcinoma in situ: a case report

Endocrine differentiation represents a pathway of neoplastic development available to a range of breast cancers. This pattern occurs in tumors with different morphological appearances as ductal carcinoma in situ (DCIS), mucinous carcinoma, a variant of lobular carcinoma, and low-grade invasive ductal carcinoma. Endocrine ductal carcinoma in situ is an uncommon entity. It occurs in older women with a mean age of 70 years. Histologically it shows expansile intraductal growth forming solid sheets and festoons transversed by delicate fibrovascular septa. Conventional microscopy permits the diagnosis in most cases. Specialized techniques such as immunohistochemistry and electron microscopy can serve as the basis of diagnosis in the absence of the appropriate morphological features. We present a 68-year-old female with a 1.5-cm firm mobile nodule of the left breast. Mammography and ultrasounds showed a 15 x 15-mm circumscribed solid lobulated nodule. The mass was excised and pathology was positive for endocrine DCIS. Although endocrine DCIS has a biologic marker profile similar to that of well-differentiated or noncomedo DCIS it may constitute a different histogenetic pathway of carcinogenesis in the breast. The tumor may exhibit the invasive characteristics of a neuroendocrine neoplasm. Larger studies and longer follow-up are needed for the determination of the clinical behavior.