Myofibroblastoma of the male breast: incidental diagnosis of a rare entity

Abstract

Myofibroblastoma of the breast is a benign tumor originated from mesenquimal cells with a very low incidence in breast pathology. Only 80 cases were reported until 2018. Eight histological patterns were described and may mimic a number of other breast diseases. A 55-years old male was diagnosed with an incidental left breast nodule. An ultrasonography with biopsy showed a 27 mm nodule compatible with myofibroblastoma. We performed a lumpectomy via modified Benelli technique. Surgery was curative and the only necessary treatment. Myofibroblastoma could be misdiagnosed and clinical differential diagnosis includes other benign and malignant breast lesions. In the setting of a diagnosis, histology may be confusing as myofibroblastoma may exhibit a wide spectrum of histological features that defines 8 variants. These subgroups can mimic malignant lesions in their histological pattern. Definitive diagnosis depends on histopathological and immunochemical results. Physicians must be aware about heterogeneity in morphological and immunochemical aspects of myofibroblastoma and his variants, as they can lead to erroneous management of the lesion. Surgery is important for a definitive and accurate diagnosis, excluding malignancy and relieving the burden of a close image-based surveillance.