Malignant fibrous histiocytoma: an uncommon sarcoma with pathological fracture of mandible.

Background: Tumors composed of cells differentiating as both fibroblasts and histiocytes have been designated fibrous histiocytomas. Only a small percentage of these lesions behave in a malignant fashion, they are called malignant fibrous histiocytoma (MFH).The occurrence of MFH in membranous bones including the mandible is quite unusual. Involvement of the mandible accounts for only 3 % of all MFH bone lesions. Recent literature revealed only a few (30) cases of MFH involving the mandible but not a single case of MFH associated with pathological fracture of the mandible, probably the first such kind of case to support antecedent trauma as an initial proliferative response for its occurence.

Case Report: A rare case of MFH involving the mandible and submandibular glands with pathological fracture in a 14-year-old boy is presented with special emphasis on the poor prognosis even after prompt therapy, its controversial histogenesis, high malignant potential, high recurrence rate and tendency to metastasise. The patient was regularly followed up for 11 months post-operatively, during which patient complained of pain in the operated region after 8 to 9 months. Though there was no clinically obvious abnormality seen, the young boy died after 11 months. The clinical, surgical, radiographic and pathological features of this lesion are discussed.

Discussion: Malignant fibrous histiocytoma, the most frequent soft tissue sarcoma of adulthood, was first described as a new malignant tumour by O'Brian and Stout in the 1960s and the details of the histopathological features of MFH were first described by Kempson and Kyriakos. Despite the frequency of diagnosis, MFH has remained an enigma as no true cell of origin has ever been identified. Treatment consists of surgical excision and in some cases chemotherapy and radiation. Early and complete surgical removal using wide or radical resection is indicated because of the aggressive nature of the tumor. The combination of infrequent occurrence, varied pathologic features, uncertain histogenesis, numerous subtypes and the many potential sites of presentation makes these tumors a challenge for the diagnostician, surgeon and oncologist. Close follow-up after treatment is important, as local recurrence is common and early metastasis to the lungs is also frequent, which are the reasons for high mortality rate in MFH.