Potential Association of BRCA Mutation and Lymphocytic Lobulitis

Lymphocytic lobulitis (LL) is a rare fibroinflammatory breast lesion historically associated with long‐standing Type 1 diabetes mellitus and autoimmune conditions. Recent evidence suggests possible links between LL and hereditary breast cancer syndromes, particularly BRCA mutations. We present the case of a BRCA1 mutation carrier who developed bilateral lymphocytic lobulitis with B‐cell predominance, discuss its clinicopathologic features, and review current literature on the intersection of autoimmune, metabolic, and genetic risk pathways.