Anatomic pathology selected abstracts
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).