Fibrous mastopathy: Clinical, imaging, and histopathologic findings of 31 cases

AIM: The aim of this study was to analyze the cases of patients with a histological diagnosis of fibrous mastopathy, diabetic mastopathy, or lymphocytic mastopathy in association with other autoimmune diseases, and to conduct histological and imaging studies as well as follow up of the lesions. METHODS: Thirty-one patients meeting predetermined histopathological criteria for diabetic mastopathy, fibrous mastopathy, or lymphocytic mastopathy were analyzed for several factors: age at diagnosis; clinical manifestations; parity; breastfeeding; use of sex steroids for hormonal replacement therapy or hormonal contraception; associated diseases; mammographic findings; breast magnetic resonance imaging and ultrasound; histological and cytological diagnosis; immunohistochemical and immunophenotyping identification of T- and B-lymphocytes and macrophages, and alpha-smooth muscle actin; and follow up. RESULTS: Fibrous mastopathy was present among diabetic and non-diabetic patients, patients with autoimmune diseases, and healthy individuals. Relapses were found in one-quarter of the lesions and spontaneous regression was observed in one case. There was a predominance of T-lymphocytes over B-lymphocytes in the fibrous mastopathic lesions (P < 0.001). Macrophages were demonstrated in 95.2% of the lesions. All of the lesions displayed reactivity for alpha-smooth muscle actin, a characteristic of myofibroblasts. CONCLUSIONS: Fibrous mastopathy does not occur in diabetic patients only; fibrous mastopathy may also occur in healthy subjects; the lesion is characterized by a higher number of T-lymphocytes over B-lymphocytes, the presence of absolute lobular lymphocytic infiltrate, reactivity for alpha-smooth muscle actin, and macrophages. Relapses were found in one-quarter of the lesions and spontaneous regression was observed in one case.