Diabetic mastopathy: a case report and literature review

Diabetic mastopathy is a rare fibroinflammatory breast disease characterized by lymphocytic lobulitis, ductitis, and perivasculitis with stromal fibrosis. This lesion often presents as a discretely palpable uni- or bilateral mass in long-standing type I diabetes and other autoimmune diseases. We report a case of insulin-dependent diabetic mastopathy, which presented clinically as an indeterminate breast lump suspicious for malignancy. The patient is a 36-year-old woman who had type 1 insulin-dependent diabetes mellitus. Mammography and ultrasonography raised a suspicion of malignancy, and an excisional biopsy was performed. A previous biopsy had shown no evidence of malignancy. Histopathological examination now showed dense keloid-like stromal fibrosis with epithelioid-like and spindly myofibroblasts and a characteristic lymphocytic infiltration around blood vessels in and around lobules and ducts, features consistent with diabetic mastopathy. The literature is briefly reviewed.