When three negatives equal a positive: Molecular updates of triple-negative breast carcinomas with favorable prognoses.

While triple-negative breast cancer (TNBC) traditionally describes an aggressive group of high-grade cancers, a rare subset of TNBC have more favorable prognoses with emerging therapeutic targets. In this article, we review the clinicopathologic and molecular advancements of select TNBC: salivary gland-type carcinomas (secretory breast carcinoma, adenoid cystic carcinoma, and low-grade mucoepidermoid carcinoma), metaplastic carcinomas (low-grade adenosquamous carcinoma and fibromatosis-like metaplastic carcinoma), and other rare triple-negative breast carcinoma subtypes (tall cell carcinoma with reverse polarity and apocrine carcinoma).