Pleomorphic Malignant Fibrous Histiocytoma Research Articles

Atypical ‘pseudosarcomatous’ variant of cutaneous benign fibrous histiocytoma: report of eight cases

Eight cases of benign cutaneous fibrous histiocytoma containing scattered, bizarre, pleomorphic cells of multinucleate or histiocyte-like type are described. All arose in adults and four had originally been diagnosed as sarcomas. Lesions of this type are not well-known and merit wider recognition in order to avoid inappropriate treatment. Differential diagnosis principally includes atypical fibroxanthoma and pleomorphic malignant fibrous histiocytoma.

Extraskeletal osteosarcoma. A clinicopathologic review of 26 cases

The clinical records and histopathologic features in 26 cases of extraskeletal osteosarcoma (ESOS) diagnosed at M.D. Anderson Cancer Center (Houston) between 1950 and 1987 were reviewed. Presentation was usually that of an enlarging soft tissue mass. The thigh (11 cases), upper extremity/shoulder girdle (three cases), and retroperitoneum (three cases) were the most common anatomic sites. Tumor size ranged from 2.5 to 30 cm. The predominant histologic pattern was osteoblastic in four cases, chondroblastic in two, fibroblastic or pleomorphic malignant fibrous histiocytoma (MFH)-like in four, giant cell type MFH-like in one, and small cell in one. Various mixtures of these patterns were seen in the remaining 14 tumors. The telangiectatic pattern was not seen as the predominant component in any primary tumor but was observed as a minor component. Thirteen tumors recurred locally and 16 metastasized; five patients had distant metastases at presentation. The lungs, bone, and soft tissue were the most frequent metastatic sites. Sixteen patients died of disease at 2 to 54 months, one patient died of unrelated causes at 61 months, seven patients were alive with no evidence of disease (NED) at 30 to 122 months, and two patients were alive with disease at 28 and 54 months, respectively. Tumor size (less than 5 cm versus greater than or equal to 5 cm) was the main prognostic factor; all patients alive with NED for whom accurate tumor measurements were available (six of seven) had neoplasms measuring less than 5 cm that were amenable to complete surgical excision. Histologic pattern and other clinicopathologic features did not significantly affect outcome.

Malignant fibrous histiocytoma

Malignant fibrous histiocytoma (MFH) was the name proposed for a group of soft tissue sarcomas on the basis of tissue culture studies which suggested the tumour cells were of histiocytic origin.' These sarcomas had been previously classified as poorly differentiated sarcomas of other types (particularly fibrosarcoma). As new histological criteria were established for both MFH and fibrosarcoma, many sarcomas were diagnosed as MFH with the result that MFH is now considered the commonest soft tissue sarcoma.2 Further work, largely by Enzinger and his co-workers at the Armed Forces Institute of Pathology, introduced the sub-types of soft tissue MFH that are recognized today-pleomorphic-storiform, myxoid, inflammatory, giant cell-rich and angiomatoid. The histopathological features of the various subtypes have been well illustrated by Enzinger and Weiss.2 The spectrum of fibrous histiocytic tumours was expanded to include benign tumours of dermis and tendon sheath, such as dermatofibroma and benign synovioma, and soft tissue tumours of intermediate malignancy such as dermatofibrosarcoma protuberans. Bone tumours with a similar histological appearance were included as benign and malignant fibrous histiocytoma of bone.35 With increasing recognition by pathologists of the histological pattern of MFH, tumours with this appearance were diagnosed as MFH at more and more sites other than the soft tissues. Two further cases ofMFH at uncommon sites are reported in this issue.6'7 Grieco and his colleagues report a case ofa 42 year old man with a 3-month history of pyrexia who was found to have a MFH of the sternum.6 The tumour was deemed inoperable and was treated with chemotherapy. Residual tumour could not be found in the sternum at autopsy. MFH is a rare bone tumour; for example, it represents only 0.8% of the 6514 primary bone tumours described from the Mayo Clinic.8 Sixty three per cent of tumours involve the long bones8 and the sternal location of the reported case is most unusual. Like Grieco's case, the majority of osseous MFHs are of the pleomorphic-storiform type.9 The optimal treatment for these tumours is chemotherapy0' followed by surgical excision and, for long bone tumours, prosthetic replacement. Aggarwal and colleagues describe a MFH of the posterior mediastinum in a 16 year old girl who presented with pyrexia.7 The tumour was surgically excised and the pyrexia subsided post-operatively. The mediastinum is another rare site for MFH. Since the initial description of two mediastinal cases by Mills et al.,'2 only single cases have been reported.'3 A further unusual feature of the two cases ofMFH in this issue is the prominent pyrexia. Many neoplasms are associated with pyrexia, notably gastric, pancreatic, hepatic and renal carcinomas and leukaemias and lymphomas. Most cases are due to associated infections or the products of tissue injury. Pyrexia in association with MFH has been noted previously'4 and was present in 2 out of 200 cases of soft tissue MFH.'5 Other occasional associations with MFH have included episodic hypoglycaemia'5 and rapid enlargement of the tumour during pregnancy.'6 Despite the evident attractiveness to pathologists of fibrous histiocytoma as a diagnosis, cracks are beginning to appear in the concept of fibrous histiocytic tumours. The diagnosis of pleomorphic MFH (the commonest sub-type) in particular is coming under strong attack with the question being posed whether it represents a real biological entity or has it become a 'diagnostic dustbin' like the poorly differentiated fibrosarcoma of old. Doubt has been cast on the original tissue culture studies'7 and it now seems probable that the tumours studied were malignant lymphomas. The finding that some cells within MFH stained with the first 'histiocytic' markers used in immunohistochemistry polyclonal antisera against alpha-I antitrypsin, alpha-I antichymotrypsin and lysozyme'89-had been taken to support histiocytic differentiation but this support has been eroded by subsequent studies showing these enzymes to be rather ubiquitous,1,2' and by studies using newer monoclonal antibodies (with greater macrophage specificity) revealing that only a very small number of true histiocytes are present within

A correlative cytologic and histologic study of malignant fibrous histiocytoma: An analysis of 40 cases examined by fine‐needle aspiration cytology

A correlative cytologic and histologic study of 40 cases of histologically highly pleomorphic malignant fibrous histiocytoma (MFH) is presented. The fine-needle aspiration biopsy was performed preoperatively, and a diagnosis of malignant soft-tissue tumor could be established in all cases. The cytologic and histologic features corresponded well with each other. The two main cell types were mono- and multinucleated, large polymorphic, often bizarre, histiocyte-like cells and atypical fibroblast-like cells. For a correct diagnosis of pleomorphic MFH, it is important to recognize atypical large polymorphic tumor cells showing signs of phagocytosis: prominent cytoplasmic vacuolization, cell debris or even well-preserved cells within the tumor cell cytoplasm. Phagocytic activity was easily demonstrated in air-dried and May-Grünwald Giemsa-stained material. The differential diagnosis of MFH as opposed to other soft-tissue sarcomas and pleomorphic carcinomas is discussed.

Ultrastructural distinctions between adult pleomorphic rhabdomyosarcomas, pleomorphic liposarcomas, and pleomorphic malignant fibrous histiocytomas

The ultrastructural features of five pleomorphic rhabdomyosarcomas, five high-grade malignant fibrous histiocytomas, and five pleomorphic liposarcomas were studied. Electron microscopy was found to be consistently useful in distinguishing between these tumors. The rhabdomyosarcomas showed thick and thin filaments in complexes and consistently contained glycogen. The malignant fibrous histiocytomas had numerous lysosomes, often in cells with ruffled borders, and contained cells showing "myofibroblastic" differentiation. The liposarcomas showed abundant and coalescing lipid droplets, sparse stroma with condensation of amorphous granular materials surrounding plasma membranes, and prominent vascularity. Fourteen of the 15 tumors could be identified on the basis of ultrastructure; thus, electron microscopic examination is an important diagnostic tool for pleomorphic tumors.

Malignant pleomorphic fibrous histiocytoma of the larynx: (Further observations)

An exceptional case of pleomorphic malignant fibrous histiocytoma of the larynx occurring in a 68-year-old male patient is reported. A significant histological documentation is given. Problems connected with histogenesis, treatment and prognosis are dealt with. Stress is laid on the need to establish differential diagnosis from other neoplasms, in particular liposarcoma and spindle-cell carcinoma.

Myxoid variant of malignant fibrous histiocytoma

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.