Diabetic mastopathy is an unusual fibroinflammatory breast lesion that characteristically presents in premenopausal women with long-standing type 1 diabetes mellitus with multiple microvascular complications. The pathogenesis of this condition is believed to involve an autoimmune reaction to the accumulation of abnormal matrix induced by hyperglycemia. Clinicopathologic features include the development of dense keloidlike breast masses that are often recurrent or bilateral or both. Clinical distinction from a malignancy can be difficult. However, the benign nature of this lesion is easily recognized on histologic examination, and it is not associated with an increased incidence of epithelial or stromal neoplasia.
A constellation of histopathologic and clinical features is necessary to make the diagnosis of diabetic mastopathy. Unnecessary surgery can be avoided in the clinical follow-up of patients with multiple, bilateral, and recurrent lesions.
Patients and Methods
Between December 1993 and December 1998, 5 premenopausal women with type 1 diabetes mellitus of 18 to 23 years' duration presented with nontender, palpable, firm-to-hard breast masses. To date, progression of the tumorlike proliferations has been bilateral and recurrent in 2 patients, bilateral in a third patient, and recurrent in a fourth. The fifth patient has developed neither bilateral nor recurrent lesions. Imaging studies did not in any patient demonstrate a focal lesion. All lesions were treated by either excisional (4 patients) or core (1 patient) biopsy. The resected specimens were examined histopathologically.
Gross examination of the specimens showed firm masses with homogeneous tannish-white cut surfaces. They measured between 3.0 and 6.0 cm in maximum diameter. Microscopic examination showed keloidal fibrosis with ductitis, lobulitis, and vasculitis. The clinical profile in combination with these pathologic features is characteristic of diabetic mastopathy.
Physicians should be aware of the association of long-standing diabetes mellitus with the development of benign fibroinflammatory breast lesions when managing these in premenopausal women. We outline the constellation of findings on clinical examination, medical history, imaging studies, and histopathologic examination that are required to make the diagnosis of diabetic mastopathy. Although these breast masses may be recurrent, they are not premalignant. In the appropriate setting, the diagnosis can be made by core biopsy, avoiding unnecessary surgeries in patients with multiple, bilateral, or recurrent lesions.