恶性纤维组织细胞瘤是软组织恶性肿瘤之一。发生在骨内者罕见。我院最近经手术清理证实一例，特报告如下。患者女，35岁，已婚，农民。因左小腿疼痛6年局部肿块2年而入院。患者2年前下蹲时出现左小腿外上方疼痛，热敷后疼痛可缓解，局部无红肿，末初及明显肿块，亦不影响睡眠及 Malignant fibrous histiocytoma is one of the soft tissue malignancies. Occurred in the bone is rare. Our hospital has been confirmed by a surgical cleanup recently. The special report is as follows. Female patient, 35 years old, married, farmer. He was admitted to the hospital because of pain in his left calf for 6 years. The patient experienced pain at the top of the left lower leg 2 years ago. His pain was relieved after the heat application. There was no redness in the area. The end of the patient had a prominent mass and did not affect sleep.