December 2025—Unusual morphologic patterns of breast carcinoma can raise diagnostic consideration for metastasis or special breast cancer subtypes and, thereby, impact clinical management and treatment. The authors conducted a study in which they described rare invasive breast cancers that mimic serous carcinoma of the gynecologic tract (serous-like breast carcinomas, SLBC) and characterized their clinicopathologic, immunophenotypic, and genetic features. The patients evaluated in the study were female (n = 15; median age, 49 years) and did not have a history of gynecologic malignancy. SLBC were characterized histologically by angulated, branched, sometimes anastomosing glands with micropapillary or pseudopapillary luminal projections in desmoplastic stroma. Most SLBC were triple negative (n = 10) or HER2 positive (n = 2) and grade 2 or 3, while some were estrogen receptor low positive/HER2 negative and low grade (n = 3). CK5/6 was positive irrespective of grade or receptor status (10 of 10).