The clinicopathologic findings in 200 cases of malignant fibrous histiocytoma (MFH) with follow-up information are presented. This tumor occurred principally as a mass on an extremity (lower extremity 49%, upper extremity 19%) or in the abdominal cavity or retroperitoneum (16%) of adults (peak incidence 61-70 years of age). It typically involved deep fascia (19%) or skeletal muscle (59%) and only rarely was confined to the subcutis without fascial involvement (7%). The MFH had variable morphologic features and frequently showed transitions from areas having a highly ordered storiform pattern to less differentiated areas having a pleomorphic appearance. The rate of local recurrence of the tumor was 44%, and of metastasis, 42%. Metastasis was most frequently to the lung (82%) and lymph nodes (32%). Factors that influenced the rate of metastasis included depth, size, and inflammatory component of the tumor. Tumors that were small, superficially located, or had a prominent inflammatory component metastasized less frequently than larger, more deeply located tumors. In our experience the MFH is the most common soft tissue sarcoma of late adult life, and many tumors previously diagnosed as pleomorphic variants of liposarcoma, fibrosarcoma, or rhabdomyosarcoma are probably examples of MFH. Although the histogenesis of this neoplasm remains controversial, we feel it is best regarded as a primitive and pleomorphic sarcoma showing partial fibroblastic and histiocytic differentiation, as reflected by collagen production and occasional phagocytosis.

Malignant fibrous histiocytoma: an analysis of 200 cases.

It has been generally recognized that malignant fibrous histiocytoma (MFH) may assume a highly myxoid, hypocellular appearance. Eighty cases of malignant fibrous histiocytoma having varying degrees of myxoid change were reviewed. These tumors typically arose on the extremities (leg, 61%; arm, 21%) of adults (peak age incidence, 60-69 years). They were usually attached to fascia (31%) or involved skeletal muscle (51%) and had a mucoid or translucent appearance. The myxoid areas consisted of widely spaced spindled and pleomorphic cells embedded in a matrix of acid mucopolysaccharides. The cellular areas were indistinguishable from those of the typical pleomorphic MFH. The rate of local recurrence of these tumors was 61%, and of metastasis, 23%, but metastasis was less likely when the tumor was small, superficially located, or had a prominent myxoid component. In fact, the degree of myxoid change was inversely related to the rate of metastasis. Therefore, because of the more favorable prognosis of the myxoid variant, it seems appropriate to separate it from the usual nonmyxoid form of MFH. The myxoid variant must also be clearly distinguished from benign myxoid lesions such as myxoma or nodular fasciitis, with which it is often confused.

Myxoid variant of malignant fibrous histiocytoma.

The probable histiocytic origin of a group of benign and malignant tumors known as histiocytomas or fibrous xanthomas appears to be well established and is based on a combination of conventional light microscopy, tissue culture and ultrastructural studies. Our experience with 23 cases of primary malignant fibrous histiocytoma of bone is presented, together with a review of additional cases documented in the literature. Particular emphasis has been placed on the radiologic aspects of primary malignant fibrous histiocytoma of bone, together with a brief review of its clinical and histologic features. The fact that the skeleton can be involved de novo rather than by direct extension from neighboring soft tissue tumors or by metastatic spread is a relatively new concept.

Primary malignant fibrous histiocytoma (fibrous xanthoma) of bone

Pulmonary Malignant Fibrous Histiocytoma: Light and Electron Microscopic Studies of One Case

Intracranial fibrohistiocytic tumors are rare. This report is concerned with a 24-year-old white male who had an 8 month history of intermittent visual disturbance. Craniotomy revealed a large, completely intradural lesion on the floor of the left anterior cranial fossa without involvement of the leptomeninges or brain parenchyma. Gross and microscopic examination revealed that the fibrogenic portion of the tumor was composed of spindle shaped neoplastic cells arranged in storiform pattern, a hallmark of fibrohistiocytic tumor. In contrast to three previously reported cases of "fibrous xanthomas" involving the leptomeninges and superficial cortex of the brain, the present lesion is clearly originated from mesenchymal stem cell of the dura. The other distinct gross and microscopic feature was the presence of myxoid component which constituted about 40% of the entire lesion. The myxoid component had not been observed in previous 5 reported cases of intracranial fibrohistiocytic lesions. Since there was cellular pleomorphism with extremely rare mitosis, it was felt that the lesion be best designated as atypical fibrous histiocytoma with myxoid stroma.

https://acsjournals.onlinelibrary.wiley.com/doi/pdf/10.1002/1097-0142%28197901%2943%3A1%3C237%3A%3AAID-CNCR2820430135%3E3.0.CO%3B2-K

Atypical fibrous histiocytoma with myxoid stroma. A rare lesion arising from dura mater of the brain

Two patients are presented who had malignant fibrous histiocytomas of the skin and soft tissue These tumors characteristically consist of a solitary mass, 05 cm to 120 cm, which has skin fixation, is circumscribed and firm Microscopically, there is a pattern of histiocytes and bizarre histiocytic giant cells intermingled in a fibrous stroma with fibroblasts arranged in a whirling pattern The lesion is treated with wide excision and skin grafting Local recurrence is common Metastasis is less common, but with metastasis the prognosis is poor

Hughes Jp

Papers

Malignant fibrous histiocytoma.