ABSTRACT Primary Non‐Hodgkin's lymphoma of the breast is rare, accounting for < 0.5% of breast cancers and ~2% of extranodal lymphomas. It often presents as a painless lump, mimicking carcinoma and complicating diagnosis. Case PresentationWe report a 65‐year‐old post‐menopausal, hypertensive, and diabetic woman with a gradually enlarging left breast mass. Imaging revealed a suspicious lesion. Core biopsy suggested poorly differentiated carcinoma, but immunohistochemistry confirmed diffuse large B‐cell lymphoma (DLBCL), activated B‐cell subtype, with high Ki‐67 (~90%). PET/CT showed localized disease. She received six cycles of CHOP chemotherapy, with rituximab added from the second cycle. Treatment was well tolerated. Follow‐up PET/CT and biopsy demonstrated complete metabolic and pathological remission. ConclusionPrimary breast DLBCL is rare and easily misdiagnosed as carcinoma. Immunohistochemistry is therefore crucial for correct diagnosis. R‐CHOP chemoimmunotherapy is the cornerstone of treatment.
Jha et al. (Thu,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: