Abstract Background Sarcomas account for less than 1% of primary breast cancers, and breast angiosarcomas are responsible for only 0.05% of all breast malignancies. The male breast has the same potential for malignant transformation as the female breast. However, due to anatomical differences in the breast and the low incidence of angiosarcoma, it is difficult to determine how male breasts can be affected by this type of tumor. Case presentation A 36-year-old male patient was admitted to the hospital with a palpable lump in his right breast. Lymphadenopathy was negative. Ultrasonography showed a hypoechoic mass with partially defined contours, measuring 4.0 × 3.0 cm, with muscle infiltration. Histological examination revealed a malignant tumor. Radical mastectomy was then performed with clear surgical margins. The patient began chemotherapy with paclitaxel. Following the second cycle of chemotherapy, he presented with headache and seizures due to a frontal lobe metastasis. Twenty days after the onset of neurological symptoms, the patient died. Conclusions Primary angiosarcomas of the male breast are extremely rare. This is the sixth case published in the literature. It is in agreement with other studies in the literature concerning clinical presentation and poor prognosis. Treatment consists in surgical removal of the tumor with clear margins and without axillary lymphadenectomy.