Abstract
Introduction: Primary malignant fibrous histiocytoma (MFH) of the breast is a rare condition that typically occurs in middle-aged women. Its presentation in older men is extremely rare, and there is very little information about primary MFH of the male breast. Presentation of case: We present the case of a 55-year-old Yemeni man who presented with recurrent MFH of the right breast. Computed tomography revealed a large heterogeneous solid soft tissue mass within the right breast region that measured 6.7 cm x 8.4 cm x 11.9 cm in size, without axillary lymph node involvement. He was treated with radical mastectomy, adjuvant radiotherapy, and chemotherapy. The postoperative histopathological findings were indicative of grade 3 undifferentiated pleomorphic sarcoma of the breast. Discussion: MFH originates from undifferentiated mesenchymal cells. Primary MFH of the breast is rare, and the most common sites are the limbs, trunk, retroperitoneum, bone, head, and neck. It has a high recurrence and metastasis rate, but lymph node involvement is not common. MFH is typically treated with surgery and radio-therapy, and the benefits of chemotherapy and routine axillary dissection are unclear. Conclusion: MFH is an aggressive tumour with a high risk of recurrence and metastasis. Its differential diagnosis is mainly reliant on analysis of the histomorphological features of the tumour. The treatment plan should be based on the size of the tumour. Simple mastectomy with a wide margin and adjuvant radiotherapy is the most common strategy that has been found to be beneficial if no invasion to the muscle.