Ultrastructure of a fibroxanthosarcoma (malignant fibroxanthoma)

Malignant fibrous histiocytoma of the floor of mouth: a case report and review of the literature

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma in late adulthood and usually occurs in the limbs, trunk, and peritoneum. Less than 10% of MFH cases occur in the head and neck region. The clinical manifestations and pathological features of MFH are atypical, and it is difficult to make a clinical diagnosis. We describe a rare case of MFH of the floor of mouth and provide our diagnosis and treatment experiences. Through this review, we also evaluate the origin, World Health Organization (WHO) classification, clinical presentations, pathological features, treatment methods, and prognosis of MFH. MFH may originate from fibroblasts or primitive mesenchymal cells. MFH was defined as undifferentiated pleomorphic sarcoma in the 2002 WHO classification of bone and soft tissue tumors. The most common manifestation of MFH is a painless enlarging nodule, often without overlying epidermal ulcers. Jaw lesions are usually found after displays of swelling, pain, paresthesia, and loose teeth. MFH is composed of pleomorphic spindle cells, usually with hemorrhage, necrosis, and lymphocyte infiltration. The main treatment method is surgical resection. Moreover, radiotherapy and chemotherapy have certain auxiliary effects. The local recurrence and distant metastasis of MFH are common, and the prognosis is poor. Therefore, determining the histopathological features of MFH and conducting appropriate immunohistochemical examinations are crucial in establishing the correct diagnosis. In-depth study is required in order to have a better understanding of head and neck MFH.

The Ultrastructure of Malignant Fibrous Histiocytoma (Case Report)

A soft tissue malignant fibrous histiocytoma was studied by light and electron microscopy. The presence of fibroblast-like cells, histiocyte-like cells, undifferentiated stem cells, and xanthomatous cells was confirmed. Fibroblast- and histiocyte-like multinucleated giant cells were also observed. The observation of lysosomes in some fibroblast-like cells, the features of undifferentiated stem cells, and the presence of cells with intermediate characteristics common to xanthomatous, histiocytic, and stem cells suggest a strict relationship among these cellular types.

Is radical oncosurgery justified for the treatment of primary malignant fibrous histiocytoma of the urinary bladder? Report of two cases and analyses of disease-specific survival rates based on a review of the literature

Disease-specific survival (DSS) rates were evaluated in 20 patients with primary malignant fibrous histiocytoma (MFH) of the bladder. The most common pathologic finding was the pleomorphic subtype of MFH (55%) with a mean tumor size of 6.8 cm. 10 patients underwent surgery without and 6 patients with adjuvant therapy. Local and systemic rates of progression were 30 and 60% after surgery only compared with 16.7 and 50% after surgery with adjuvant therapy. Although none of the patients showed metastatic dissemination at the time of diagnosis, overall 1- and 2-year DSS rates of only 47.8 and 31.9% were observed. Hence, after the onset of clinical symptoms, the disease runs a very aggressive course regardless of the therapeutic options employed. Although distant dissemination seems to be rare at the time of diagnosis, the prognostic outcome is dismal. The rarity and inconsistency of the currently available case reports on MFH of the bladder hampers the development of therapeutic guidelines. Advanced studies enrolling a larger number of patients with appropriate clinical and pathological data are needed to compare the beneficial effects of various treatment options.

The Rise and Fall of Malignant Fibrous Histiocytoma

The term malignant fibrous histiocytoma was coined by Stout and associates in the 1960s to encompass pleomorphic soft tissue sarcomas presumably derived from histiocytes that are capable of fibroblastic transformation. The concept was reaffirmed in the following 2 decades and malignant fibrous histiocytoma thus was regarded as the most common soft tissue tumor in older adults. However, recent more critical clinicopathologic, ultrastructural, and immunohistochemical studies have shown that malignant fibrous histiocytomas are not derived from histiocytic "facultative fibroblasts" and many neoplasms so diagnosed actually are pleomorphic subtypes of other sarcomas. Meticulous electron microscopic and immunohistochemical investigations also found that the more common storiform-pleomorphic, myxoid, and perhaps the giant cell subtypes are composed of variable mixtures of fibroblasts and phenotypically modulated fibroblastic cells, notably myofibroblasts and histiofibroblasts. On the basis of these findings, we propose a new classification for the above subtypes of so-called malignant fibrous histiocytoma, the majority of which are variants of pleomorphic fibrosarcoma.

Cerebellar malignant fibrous histiocytoma: case report and literature review

OBJECTIVE AND IMPORTANCE

Malignant fibrous histiocytoma in the central nervous system is uncommon. Fewer than 70 cases have been documented and, to the best of our knowledge, this is the first case arising from the cerebellum.

CLINICAL PRESENTATION

A 44-year-old woman presented with headaches, vomiting, and dizziness. A neurological examination revealed right cerebellar syndrome. Brain computed tomographic scans revealed an isodense tumor in the right cerebellar hemisphere. The breast ultrasonographic, bone scintigraphic, and thoracoabdominal computed tomographic findings were normal.

INTERVENTION

The patient was surgically treated. The tumor recurred 1.5 months later, demonstrating hemorrhagic characteristics on brain computed tomographic scans. The patient underwent a second operation, followed by radiotherapy.

CONCLUSION

Malignant fibrous histiocytoma is still a controversial entity, and the lack of specific criteria means that it must be diagnosed via the process of elimination. With currently available therapy, our review can provide only a very poor prognosis. The median survival time was 27 months. In attempts to develop better therapeutic strategies, total excision and radiotherapy seem to represent the best treatment approach.

Case report: malignant fibrous histiocytoma following radiation therapy of fibrous dysplasia

Malignant fibrous histiocytoma commonly occurs spontaneously. In some cases it follows previous therapeutic or incidental irradiation, or miscellaneous pre-existing osseous conditions. Recently, it has been associated with total hip arthroplasty. We report a case of malignant fibrous histiocytoma following radiation therapy of fibrous dysplasia and review the relevant literature.

Brain metastases from primary lung malignant fibrous histiocytoma: a case report

Primary malignant fibrous histiocytomas are rare. The authors report on a 56-year-old man who presented with neurological symptoms due to cerebral metastasis of a primary malignant fibrous histiocytoma of the lung.

Head and Neck Malignant Fibrous Histiocytomas

Malignant fibrous histiocytoma of the head and neck is a rare tumor with less than 50 total cases reported in the literature. Its rarity and complex histopathology combine to make it a difficult diagnosis. Two cases are described. Pathology characteristics are discussed. The traditional treatment of choice is wide surgical excision. Radiation therapy is usually reserved for recurrent, unresectable, or extremely aggressive tumors.

Malignant fibrous histiocytoma of the maxilla--a report of two cases

Two cases of malignant fibrous histiocytoma of the maxilla are reported. The tumours were excised via a combined temporal and intra-oral approach in order to gain adequate surgical access and minimise the aesthetic deformity. One patient required orbital exenteration.

Intracerebral malignant fibrous histiocytoma: case report and review of the literature

A 50-year-old woman developed an intracerebral malignant fibrous histiocytoma at the site of a previously clipped aneurysm in the right temporal lobe. This tumor rarely originates within the brain. Review of the literature suggests that postoperative and/or postirradiation effects may contribute to the growth of this particular tumor.

Malignant fibrous histiocytoma of the liver--a case report

A case of surgically confirmed primary malignant fibrous histiocytoma of the liver is presented. A 35-year-old man was admitted to hospital with an epigastric mass. No abnormal laboratory findings, including tumor markers, were detected. Ultrasound and computed tomography showed the main tumor in the left lateral segment and a daughter nodule in the posterior segment of the liver. Arteriography demonstrated a slightly hypervascular mass in the left lateral segment. Histological examination of the resected tumor showed bundles of spindle cells with a focal storiform pattern, which were intermingled with bizarre giant cells, therefore a diagnosis of malignant fibrous histiocytoma was made.

Recurrent malignant fibrous histiocytoma with expression of cytokeratin

A case of locally recurrent malignant fibrous histiocytoma was documented in a 70-year-old man. He first noticed a subcutaneous nodule forty years previously. The tumor was surgically removed four times during the last four years with local recurrence on every occasion. In the recurrent tumors, the tumor cells almost completely replaced the whole dermis and invaded skeletal muscles. They were composed of pleomorphic spindle cells arranged in a storiform pattern and bizarre histiocytic cells, which were present principally in the deeper portions of the tumor. Both types of tumor cells showed marked nuclear atypicality. In the primary tumor, surrounding a large necrotic area, spindle-shaped cells were arranged in a storiform pattern. These tumor cells exhibited only mild nuclear atypia. The recurrent tumor was strongly positive for vimentin and alpha-1-antichymotrypsin. Most tumor cells were also weakly positive for KL1, a monoclonal antibody for keratin. A Western-blot analysis revealed the presence of two bands (62 and 69 Kd) reacting with KL1 in the fractions which were obtained from the tumor according to the method for keratin extraction.

Myxoid malignant fibrous histiocytoma of the bladder

Although the most common soft tissue sarcoma of adulthood, malignant fibrous histiocytoma (MFH) is an extremely rare tumor of the urinary bladder. Only three well-documented cases have been reported in the world literature. The patient presented in this report represents the first case of the myxoid variant to develop in the urinary bladder. Whereas all previous patients with MFH of the bladder had intermittent hematuria, this patient's chief complaint was bladder outlet obstruction due to extension of the tumor into the prostate. He was managed with radical cystoprostatectomy, postoperative radiation therapy to the tumor bed, and adjuvant chemotherapy using doxorubicin. The patient tolerated the therapy well and was disease-free at the 3-year follow-up visit. The histogenesis, clinical features, pathologic characteristics, and treatment considerations of this rare bladder tumor are discussed in detail.

[Malignant fibrous histiocytoma of soft tissue: atypical presentations. Value of combined surgery and chemotherapy]

The authors report five cases of malignant fibrous histiocytoma of the soft tissues, some of them with atypical presentation (necrotizing tumor, hypereosinophilic syndrome, dermatomyositis). This is the first case of polymyositis associated with malignant fibrous histiocytoma. The tumor occurs between the fifth and the seventh decade, principally as a mass on the proximal lower limb. Local recurrence and metastasis occurs in 50% of patients. Prognosis is dependent on both the surgical possibilities and the characteristics of the tumor (site, size, histologic grade). Surgery alone is inadequate. Adjuvant chemotherapy improves the 5-year survival.

Osteoclasts are present in the giant cell variant of malignant fibrous histiocytoma

We assessed the osteoclast-like giant cells in a giant cell-rich variant of malignant fibrous histiocytoma (MFH) for characteristics which are specific for osteoclasts, including excavation of bone and binding of osteoclast-specific monoclonal antibodies. Excavations characteristic of osteoclastic activity were found when the bone slices were inspected in the scanning electron microscope after incubation. Two monoclonal antibodies which bind specifically to osteoclasts showed strong membrane reactivity. These results provide strong evidence for the osteoclastic nature of the giant cells in this variant of the MFH. Osteoblasts are known to control the function of the osteoclast, and since there is bone formation present in at least half of the giant cell-rich variant of MFH it may be that it is the cells with properties peculiar to osteoblasts within the tumour which are responsible for the recruitment of the osteoclasts.

The annulate lamellae--from obscurity to spotlight

This review aims to provide a comprehensive and in-depth survey of a cell organelle, the annulate lamellae, that is widely distributed and especially prevalent in both female and male sex cells as well as tumor and cancer cells. The organelle is also present in many somatic cells and plant cells. Emphasis is placed on the contributions that electron microscopy and associated experimental approaches have made in providing information about the distribution, ultrastructure, morphogenesis and relationships of annulate lamellae to other cellular organelles, especially the nuclear envelope and endoplasmic reticulum, as well as cell product. An increasing number of experimental manipulations have recently been shown to alter, either increase or decrease, the amount of annulate lamellae and these studies are explored in depth. Information about the origin and morphogenesis of annulate lamellae in different cells is summarized and extensive coverage is given to several hypotheses about possible annulate lamellae function. A detailed bibliography provides a thorough compilation of research dealing with annulate lamellae. A major goal of this extensive review is to generate increased awareness of, and interest in, this cell organelle for students and investigators of the cell who, by bringing current techniques in cell and molecular biology to bear, might focus and intensify studies on the function of an organelle whose precise role in the cell is presently enigmatic.

Malignant fibrous histiocytoma: a report of two cases arising in sites of previous irradiation

This report illustrates two cases of malignant fibrous histiocytoma of the maxilla arising in sites which had been irradiated. The prognosis for such tumours in the jaws appears to be very poor.

Malignant fibrous histiocytoma of the lung

Malignant fibrous histiocytoma (MFH) is among the most common soft tissue sarcomas of adult life, but rarely occurs elsewhere. We report an example of primary MFH of the lung and review 15 previously reported acceptable cases with current follow-up information. Histologically, the tumor in our case was pleomorphic with storiform and fascicular areas. Tumor cells showed positive immunostaining for alpha 1-antitrypsin, alpha 1-antichymotrypsin, and vimentin. Stains for desmin, cytokeratin, myoglobin, epithelial membrane antigen, S-100 protein, and lysozyme were negative. Electron microscopic study showed histiocyte-like, fibroblast-like, intermediate, and undifferentiated tumor cells. A variety of methods were used to treat these patients. Two patients survived for 5 or more years, two were alive and well at 8 and 12 months, respectively, two were alive with metastatic tumor at 3 and 18 months, respectively, and ten patients died of tumor, with an average survival of 1 year.

Cellular junctions in a spectrum of human malignant tumors

Cellular junctions in tumors are often considered a hallmark of epithelial differentiation. However, junctions are also seen in tumors having a different differentiation. This observation prompted us to study cellular junctions in malignant nonepithelial tumors. We found a variety of cellular junctions in such tumors, although the majority were poorly formed. This observation is of importance for diagnostic purposes. We have also tried to clarify the nomenclature of cellular junctions as applied in tumor diagnosis by proposing a systematic categorization of terms in everyday use by pathologists and by referring more extensively to the term paired subplasmalemmal densities (PSD) for non-well-formed junctions.

An immunohistochemical study of differentiation in malignant fibrous histiocytoma

Immunohistochemistry was used to examine 10 cases of malignant fibrous histiocytoma. Malignant cells in all cases expressed vimentin and in eight there was co-expression of either desmin or neurofilament, both of these being present in four cases. In addition, cytokeratin was found in one case. In each tumour, a population of small cells was identified which had the staining characteristics of benign macrophages, and this was distinct from the tumour cells. This study supports the concept that malignant fibrous histiocytoma is a tumour of mesenchymal cells rather than of histiocytes and emphasizes the diversity of its cytostructure.

Malignant fibrous histiocytoma induced by intra-articular injection of 9,10-dimethyl-1,2-benzanthracene in the rat. Pathological and enzyme histochemical studies

Malignant fibrous histiocytoma (MFH) was produced by injection of 9,10-dimethyl-1,2-benzanthracene (DMBA) into the rat knee joint. The tumor was observed in or around the knee in nearly all the animals 13 to 36 weeks after the initial DMBA administration. Histologically, these lesions were of the storiform-pleomorphic type (39/58, 67.2%), myxoid type (9/58, 15.5%), or giant cell type (8/58, 13.8%). Six cell types reported in human MFH were confirmed and phagocytosis of 0.81-micron latex particles by histiocyte-like cells was noted by electron microscopic examination. Acid phosphatase, beta-glucuronidase, and alpha-naphthyl acetate esterase were positive in enzyme histochemical examinations. Acid phosphatase activity was electron microscopically noted primarily in the lysosomes and the Golgi apparatus of the histiocyte-like cells. Cells from the storiform-pleomorphic (M1) and myxoid (M2) type tumors were serially transplanted subcutaneously in the back of the rats, and are now at the thirtieth and fortieth passage, respectively. They also were studied by enzyme histochemical and electron microscopic techniques. Our observations suggested an undifferentiated mesenchymal cell origin of MFH. Transplantable MFH can be produced in rats by intra-articular injection of DMBA, and lesions thus produced are a useful experimental model for the investigation of the histogenesis and the effect of chemotherapy of MFH.

Malignant intracranial fibrous histiocytomas. Histologic, ultrastructural and immunohistochemical studies of two cases

Two cases of malignant intracranial fibrous histiocytoma are presented. In Case 1 the tumour arose from the meninges and showed a disseminated spread throughout the neuroaxis. In the second case the tumour appeared to arise from within the brain substance. In this case surgical intervention and radiotherapy appeared to have achieved a cure, since no residual tumour was found at autopsy. The tumours were examined using ultrastructural and immunohistochemical techniques, which appeared advantageous in delineating this rare tumour from other intracranial neoplasms.

Malignant fibrous histiocytoma with widespread metastasis and pulmonary cancer

An autopsy case of malignant fibrous histiocytoma (MFH) with widespread metastases and lung carcinoma in a 64-year-old Japanese woman is reported. The initial signs were cough and sputum, followed by hemosputum. A chest X-ray photo showed a right pleural tumor, which could not be identified from a biopsy specimen, but was identified as MFH by light and electron microscopic studies on biopsy specimens of tongue tumors. Autopsy examination revealed metastases of the MFH to the brain, lung, liver, kidney, adrenal, pancreas, retroperitoneum, and some bones, and pulmonary adenocarcinoma.

Congenital fibrosarcoma: a congenital fibrous histiocytoma

Using immunoperoxidase PAP technique in 2 cases of congenital fibrosarcoma, a great number of cells showed positive stain for alpha-1-antitrypsin (A1AT) and alpha-1-antichymotrypsin (A1ACT), both considered to be good histiocytic markers. The ultrastructure in 1 case also provides evidence of histiocytic differentiation. These findings suggest that congenital fibrosarcomas are actually congenital fibrous histiocytomas and may explain the presence of inflammatory infiltrates as in some malignant fibrous histiocytomas.

Malignant fibrous histiocytoma of the liver

A 59-yr-old man was admitted to the hospital for evaluation of right upper quadrant pain, anorexia, weight loss, and low-grade fever of 2-mo duration. During his evaluation, an abnormal liver ultrasound and computed tomography scan demonstrated what proved to be an avascular hepatic lesion. At surgery, the diagnosis of malignant fibrous histiocytoma was established. We present herein our findings of what we believe to be the first reported study of malignant fibrous histiocytoma of the liver.

Annulate lamellae observed in human prostatic carcinoma

Annulate lamellae (AL) were observed in only three out of 40 cases of human prostatic carcinoma, but not in 20 cases of benign prostatic hyperplasia and 11 cases of presumably normal prostatic tissues. AL showed the continuity with the rough endoplasmic reticulum and seemingly the nuclear membrane consisting of lamellar or concentric arrangement of stacked membranes and occasionally annular structures. In addition, annuli were detected in the rough endoplasmic reticulum near the stacked membranes which were devoid of ribosomal attachment. These results disclosed that in human prostatic tissues, AL could be only rarely detected in actively dividing cancer cells, and were seemingly the temporary transitional structures transforming from the nuclear membrane to the rough endoplasmic reticulum.

Malignant fibrous histiocytoma of the maxilla. Case report and review of the literature

A case of malignant fibrous histiocytoma (MFH) occurring in the maxilla is presented. Although MFH is now recognised as the most common soft tissue sarcoma of late adult life, it rarely occurs in bone and then more usually in the long bones. Presentation affecting the facial bones and skull is extremely rare, but should be considered in the differential diagnosis of bone tumours affecting the maxilla. Skeletal lesions appear more aggressive than those in soft tissues. Early radical excision is the treatment of choice although radiotherapy for inoperable tumours may lead to regression, as in the case presented here.

A histological and immunoenzymatic study on the histogenesis of "giant cell tumor of bones"

We carried out a prospective histologic and immunoenzymatic study, using lysozyme and AI-antichymotrypsin, of 15 well documented cases of giant cell tumors of bones. The histologic appearance of the majority of the tumors was characterized by great pleomorphism. The predominant histologic patterns could be classified as either fibroblastic or histiocytic. Mitoses were seen exclusively on stromal mononuclear cells. All tumors showed positive marking with both lysozyme and AI-antichymotrypsin. The enzymatic activity was more pronounced in areas of conventional histology and appeared as coarse orange-brown granules in the cytoplasm of many mononuclear and multinucleated giant cells. Enzyme-positive cells were less frequently found in fibroblastic areas of the tumor and especially in areas with minimal differentiation. The results indicate that giant cell tumor of bones may result from the neoplastic proliferation of mononuclear cells which in many areas of the tumor differentiate to either fibroblasts or histiocytes. Thus, giant cell tumor of bones may be analogous to fibrohistiocytic tumors of soft tissues.

Nitrosamide-induced sarcomas in the gastric pylorus of hamsters. A histological and ultrastructural survey on the histogenesis

A histological and ultrastructural survey on the histogenesis of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric sarcomas in hamsters was attempted. Within 3 months after the beginning of oral administration of MNNG, simple spindle cell proliferation in the submucosal zone of the pyloric region of the glandular stomach was evident. By 5-6 months, the cells had acquired a sarcomatous appearance. Ultrastructurally, the spindle cells in the early stage, were divided into 3 types, i.e., angiogenic cells, fibroblastic cells, and primitive mesenchymal cells. Similarly, those in the late-appearing sarcomatous tumors were also classified into different types of angiogenic, fibroblastic, histiocytic and miscellaneous cells. Among the cell population of the 2 major groups, angiogenic cells were the most predominant cell type. Some morphological transition appeared to occur between the corresponding cell types at the early and late stages. DNA content of cell nuclei of the representative forms of the nitrosamide-induced sarcomas was higher than that of early appearing spindle cells. Thus, the evidence suggests that the early appearing spindle cells are precursors for the gastric sarcomas.

Malignant fibrous histiocytoma of the breast. A case report and review of the literature

The clinicopathologic features of a malignant fibrous histiocytoma arising in a female breast are presented. Seven cases have been previously reported. These may be divided into three subgroups based on history and pathologic findings. Three of the seven occurred in women without a history of other tumors or previous irradiation. One appeared with a cystosarcoma phyllodes, and three arose following radiation for carcinoma of the breast. The patient in this study had received no radiation. Treatment has been based on surgical resection; the roles of chemotherapy and radiation are uncertain. Although resection alone in the first subgroup has lead to no reported mortality, the small number of cases and the relatively short follow-up does not allow a meaningful assessment of the prognosis in this disease.

Fibrous histiocytomas of the oral and maxillofacial regions

Fibrous histiocytomas of the oral and maxillofacial regions are rare. The present study analyzes a sample of 63 cases from the literature together with 7 personally observed cases. Age, sex, site, size, clinical behaviour, treatment and survival were evaluated and related to a histological classification based on that of Rosai (1981). Lesions were assessed for histological criteria which would place them in one of 2 groups: fibrous histiocytoma (FH) or pleomorphic fibrous histiocytoma (PFH). Within these 2 histological groups the cases were subdivided into clinically benign, aggressive or malignant lesions. Thirty-nine cases (56.0%) were classified as FH and 31 cases (44.0%) as PFH. The mean age of male patients with PFH was significantly higher than female patients with FH (t = 3.05; d.f. 37; p less than 0.0025). Lesions in the PFH group involved bone more frequently than those in the FH group (Yate's Chi2 = 16.66; d.f. 1; p less than 0.00025). Lesions involving bone for both histological groups were more likely to be aggressive or malignant than soft-tissue lesions (Yate's Chi2 = 29.9; d.f. 1; p less than 0.00025). Soft-tissue lesions were usually less than 5 cm in greatest diameter. Radiographic features of malignancy for lesions with bone involvement is of prognostic importance regardless of the histological appearance of the lesion. The majority of the lesions under study were from the deep tissues of the oral and maxillofacial regions.

Kidney fibroxanthoma (malignant fibrous xanthoma): a rare tumor and an unusual cause of retroperitoneal hemorrhage

A case of kidney fibroxanthoma (malignant fibrous xanthoma, malignant variant of xanthogranuloma), a rare malignant neoplasm of kidney, is described. In addition to the typical histologic features of retroperitoneal xanthogranuloma, this tumor showed obvious pleomorphism and mitotic activity of the histiocytes. We present this case in view of the rarity of this neoplasm and the unusual presentation as massive retroperitoneal hemorrhage.

Primary malignant fibrous histiocytoma of the lung. A clinicopathologic and ultrastructural study of five cases

Primary sarcomas of the lung are rare malignant neoplasms which have usually been classified as fibrosarcomas or as leiomyosarcomas. Only five cases of primary malignant fibrous histiocytoma (MFH) of the lung have previously been reported in the literature. The authors reviewed 10 cases of primary pulmonary sarcoma of the lung seen at their institution during the last 12 years, and five of these cases met the morphologic criteria for the diagnosis of MFH. The morphology in these cases is identical to MFH of other body locations, and shows a combination of fibroblast-like and histiocyte-like cells at both the light and electron microscopic level. By electron microscopic examination there was no evidence for anaplastic carcinoma, rhabdomyosarcoma, or leiomyosarcoma. Of the three patients with adequate follow-up, one patient is alive without evidence of disease at 10 years, one died at 5 years without evidence of recurrent sarcoma, and one died at 7 months with liver metastasis. Two other patients are alive without recurrence at 8 months and 1 year, respectively, following surgery. Because MFH is primarily a tumor of the soft tissues of the extremities, patients with MFH of the lung must be carefully evaluated to rule out a metastatic origin. The reported prognosis in patients with primary MFH of the lung is poor, but early surgical resection does offer the possibility of a cure.

Malignant fibrous histiocytoma arising in previous surgical sites. Report of two cases

Two patients who developed malignant fibrous histiocytoma in previous surgical sites are reported. One patient developed malignant fibrous histiocytoma in an amputation site, and the other patient developed it in a previous hernioplasty scar. Both patients presented with a mass, clinically interpreted as a subcutaneous abscess. The light microscopic and fine structural features of these tumors are described. A possible causal relationship between previous surgery and malignant fibrous histiocytoma is discussed in view of other reported cases arising in various conditions following chronic reparative reactions.

Malignant fibrohistiocytoma (MFH) of the breast. Primary and postirradiation variants - an ultrastructural study

Two cases of malignant fibrohistiocytoma (MFH) of the mammary gland are presented. Patient No. 1 had been previously locally irradiated for an infiltrating duct carcinoma (5600 rads) 5 years earlier. Prognosis of postirradiation MFH was poor and the patient died within the first year after diagnosis of the second malignancy. The primary MFH (Case No. 2) is free of disease after a 5-year follow-up period, having been submitted to a radical mastectomy. Histological appearance is in accordance with previously published cases. No marked differences existed between both cases at optical level. Lysozyme (PAP technique) was observed within isolated histiocytes. Electron microscopy distinguished up to 4 different cell types within the neoplasm: fibroblasts, histiocytes, mixed cells of fibro-histiocytic appearance, and more immature blastemal cells. Transitional forms existed among them.

Primary laryngeal malignant fibrous histiocytoma: review of the literature and report of seven cases

After describing 4 new cases of malignant fibrous histiocytoma of the larynx (3 cases had been recently published), the authors review the literature, from which it appears that 16 such lesions of the larynx have been reported (including their 7 cases). Malignant fibrous histiocytoma usually occurs in the soft tissues, tendons and joints of the upper and lower extremities, and is uncommon in the head and neck--though not exceptional. The lesion is a mesenchymal tumor probably of histiocytic origin and may be divided into 6 subtypes, i.e., pleomorphic, fibrous, giant cell, angiomatoid, myxoid and inflammatory, to be distinguished on the basis of the predominant feature. The tumor has an aggressive biologic behavior as it tends to recur and to metastasize to distant organs. The treatment of choice is surgery and adjuvant combination chemotherapy which at times may improve the survival rate.

Malignant fibrous histiocytoma: an ultrastructural study of eleven cases

Eleven cases of malignant fibrous histiocytoma were examined electron microscopically. In six of seven cases with storiform-fascicular histologic features and in two cases with a myxoid pattern, no malignant-appearing histiocyte-like cells were identified. The neoplastic cells were fibroblasts and myofibroblasts, occasionally admixed with lymphocytes and benign-appearing histiocytes. Only in the other three cases (two pleomorphic sarcomas and one tumor with a storiform-fascicular pattern) were malignant cells with the features of histiocytes identified. The authors propose that some neoplasms with a storiform-fascicular pattern would be more accurately classified as fibrosarcomas than as histiocytomas and speculate on the possible histogenesis of those tumors that do contain histiocyte-type cells.

Lymphocytosis in a patient with malignant fibrous histiocytoma

Malignant fibrous histiocytoma is an uncommon soft-tissue sarcoma. Patients with malignant fibrous histiocytoma may present with unusual clinical findings and an apparent association with malignant hematopoietic disease has been reported. We describe a patient in whom a diagnosis of chronic lymphocytic leukemia was made simultaneously with discovery of a large, retroperitoneal malignant fibrous histiocytoma. Following surgical debulking of the tumor, the patient's blood and bone marrow findings returned to normal.

Benign fibrous histiocytoma of the skin. A morphologic study of 290 cases

Two hundred and ninety cases of benign fibrous histiocytoma of the skin are reviewed. Their frequency, distribution according to age, sex and sites, and the architectural and cytological features of the tumors are analyzed. Ninety two cases (31,7%) were male and 198 cases (68,3%) were female. The tumors were most frequently found between second and fourth decades and located mainly in the extremities. Twenty three cases were clinically diagnosed as malignant tumors. Five cytological patterns of benign fibrous histiocytoma of the skin are described: fibrous, vascular, xanthomatous, pleomorphic and giant cell histiocytoma. Their probable histogenesis and the spectrum of morphological variants are discussed.