Abstract
Malignant fibrous histiocytoma is a soft tissue sarcoma that most commonly occurs in the extremities and rarely metastasizes cutaneously. A 79-year-old male patient consulted a dermatologist 11 months after recognizing an intractable ulcer on the right mandible. Punch biopsy revealed eosinophilic tumor cells in the dermal area and proliferation of rich spindle cells. Malignant fibrous histiocytoma or atypical fibroxanthoma was suspected and he was referred to our hospital. Red plaque tumors on the right mandible and right temple were 30 mm and 15 mm in size, respectively. The right mandible lesion was ulcerated. Immunohistochemically, the lesions were positive for CD10, CD74 and alpha-smooth muscle actin. Radiological analysis revealed multiple organ metastases, including bone, liver, lung and skin on the right temple. The patient was diagnosed with malignant fibrous histiocytoma, stage IV and died 8 weeks after the first visit due to respiratory failure. Cutaneous malignant fibrous histiocytoma has a poor prognosis resulting in death.