Low-Grade Adenosquamous Carcinoma of the Breast Masquerading as a Fibroepithelial Lesion on Core Biopsy: A Challenging Case.

Abstract

Diagnosing low-grade adenosquamous carcinoma (LGASC) presents significant challenges due to its subtle morphology, variable immunohistochemical expression, and resemblance to benign lesions like radial scar and complex sclerosing lesions. We present a case of a 53-year-old woman with a subareolar mass initially thought to be a fibroepithelial neoplasm on core biopsies. Subsequent wide excision revealed LGASC with oestrogen receptor expression (weak to moderate intensity, 40% of tumour cells). These findings, rarely reported, highlight the difficulty of diagnosing LGASC on small tissue samples.