Primary neuroendocrine carcinoma of male breast: A cytologically diagnosed rare entity.

Primary neuroendocrine (NE) carcinoma of the male breast is very rare. NE breast cancers encompass a heterogeneous group of tumors exhibiting morphological features similar to those of NE tumors of the gut and lung. They express one or more NE markers in at least 50% of the tumor cells. They are rare lesions representing about 2-3% of all breast cancers and more frequently affecting elderly patients. The present case report deals with a NE breast carcinoma in an 80-year-old male who presented with a right breast mass and axillary lymphadenopathy. The cytological features were suggestive of NE carcinoma. A thorough clinical evaluation helped confirm the primary nature of the tumor. The histopathology and immunohistochemistry helped confirm the cytological diagnosis. The histogenesis and prognostic implications of this rare breast tumor with predominant NE differentiation, unusually occurring in a male, is discussed here.