Palisading subcutaneous fibrous histiocytoma

A case of palisading subcutaneous fibrous histiocytoma, a very rare variant of fibrous histiocytoma (dermatofibroma), arising in the wrist of a 41-year-old man is presented. An unencapsulated subcutaneous tumor measuring 0.8 x 0.8 x 0.7 cm was histologically characterized by predominant nuclear palisading and a peripheral area with a pattern quite characteristic of conventional fibrous histiocytoma. Immunohistochemically, the tumor cells were strongly positive for vimentin, alpha-smooth muscle, and muscle actin, but negative for S-100 protein, indicating a fibroblastic or myofibroblastic nature. The patient has been well without recurrence for 6 years and 8 months after the excision. This neoplasm should be differentiated from benign and malignant skin or soft tissue tumors with a palisading pattern. Pathologists and clinicians should know of the existence of this type of fibrous histiocytoma and should avoid overdiagnosis and overtreatment.     

Inflammatory fibrous histiocytoma of the penis

A 62-year-old man presented with a penile mass which was diagnosed histologically as an inflammatory fibrous histiocytoma. The predominant inflammatory cells in the tumour were eosinophils. The tumour regressed after radiotherapy but recurred eight months later, when it showed very few inflammatory cells. At no time did this patient have an elevated white cell count. This tumour has not previously been reported on the penis, nor have eosinophils been described as the principal inflammatory cell in these tumours.     

Angiomatoid malignant fibrous histiocytoma

Summary A case of an angiomatoid malignant fibrous histiocytoma is presented. The electron microscopic findings demonstrate the presence of a variety of tumor cell types including smooth and striated muscle cells. This indicates that malignant fibrous histiocytoma originates from a pluripotent primitive mesenchymal cell.     

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.     

Malignant fibrous histiocytoma of the pancreas

An extremely rare case of malignant fibrous histiocytoma In the pancreas Is reported. A 70-year-old man complained of upper abdominal discomfort. A tumor in the head of the pancreas was demonstrated by ultrasonography and computed tomography. The surgical specimen revealed a relatively well demarcated tumor, 9 × 7 × 6.5cm in size. Microscopically, fibroblastic, histiocytic, and muitinucleated giant tumor cells were observed in the myxoid area, but some tumor cells had proliferated in a storiform-pleomorphlc pattern. Immunohtstochemically, some tumor cells were positive for lysozyme, α-1-antitrypsin, α-1-antichymotrypsin, and vimentin. Electron microscopically, tumor cells showed a combination of fibroblastic and histiocytic features. The patient Is currently well with no evidence of recurrence or metastasis 22 months after operation.     

Malignant fibrous histiocytoma of the lung

Summary A case of malignant fibrous histiocytoma of the lung is reported. The tumour margin was well circumscribed, showing an expanding border and no capsule. The main part of the tumour was composed of spindle-shaped fibroblast-like cells arranged in broad fascicles with a partially storiform pattern. Other parts of the tumour were arranged in a haphazard pattern, containing many mononucleated and multinucleated giant cells. Ultrastructurally six differnt cell types were encountered. The dominant type was a fibroblast-like cell; also present were many giant cells and some histiocyte-like cells, together with their intermediate forms, and few undifferentiated mesenchymal cells. We consider this tumour to have developed from the peribronchial connective tissue; it has the same cellular composition as the malignant counterpart arising in soft tissues.     

Malignant fibrous histiocytoma of the esophagus

A 78-year-old man presented with an esophageal polyp that was confirmed by Immunohistochemistry and electron microscopy to be malignant fibrous histiocytoma. The tumor was comprised of a proliferation of spindle-shaped cells admixed with bizarre giant cells. These tumor cells were immunoreactive for smooth muscle actin, vimentin, α-1-arrti-chymotrypsin and CD68. Electron microscopic examination revealed the myoflbroblastic and histtocytic features of the tumor cells. No elements of epithelial or myogenic differentiation were found in the tumor. Malignant fibrous histiocytoma of the esophagus is extremely rare, with 10 cases being documented so far in the literature. The differential diagnosis of pteomorphic tumors of the esophagus is discussed.     

Malignant fibrous histiocytoma

Summary The ultrastructural findings in 17 cases of malignant fibrous histiocytoma (MFH) are described. The tumors consisted of fibroblast-like cells and histiocyte-like cells in different proportions in different cases. Intermediate, undifferentiated, xanthomatous and multinucleated giant cells were also identified. In 12 of 17 cases myofibroblasts were evident. Acid phosphatase activity was detected cytochemically in the Golgi zone, endoplasmic reticulum and lysosomes (GERL) mainly within histiocyte-like cells, in three cases. These observations indicate that the GERL of the tumor cells are engaged in the formation of lysosomes. The polymorphic cellular composition, including undifferentiated cells, lends support to the concept that the MFH originates from a primitive multipotent undifferentiated mesenchymal cell.Supported by Grants-in-aid for Cancer Research from the Ministry of Health and Welfare (52-1), and from the Ministry of Education, Science and Culture (401057) of Japan and by a Grant from the Fukuoka-ken Anti-Cancer Association. 1976Presented at the 69th Annual Meeting of the Japanese Pathological Society on June 26, 1980, Sapporo     

Osteosarcoma with features mimicking malignant fibrous histiocytoma

Summary Three osteosarcomas (OS) with features resembling malignant fibrous histiocytoma (MFH) were selected and investigated to identify any clinico-pathological similarities. In all cases there was no significant difference from conventional OS on the radiography and laboratory data. The appearance of MFH-like features within the whole tumour tissue varied from 7% to 55%. It was composed of spindle-shaped cells arranged in short irregular fascicles and a storiform pattern admixed with osteoclast-like giant cells, but devoid of neoplastic osteoid. Such spindle-shaped cells had a poorly developed rough endoplasmic reticulum and expressed a strong alkaline phosphatase activity as well as vimentin. A series of allografts to athymic mice using the MFH-like tissues also showed histologically a proliferation of plump spindle-shaped cells with a storiform pattern lacking osteoclast-like giant cells, and intensely positive for alkaline phosphatase. These findings indicate that the MFH-like features are identified as modulated OS. The constituting cells are most likely to be poorly developed with possible phenotypic alteration in the maturation stage of osteoblastic cell lineage, but different from conventional MFH of bone as regards their distinct histochemical pattern.     

Inflammatory malignant fibrous histiocytoma of kidney: a case report

Among the renal sarcomas, inflammatory malignant fibrous histiocytoma (MFH) is an extremely rare presentation. A 45-year-old woman presented with acute retention urine following an episode of gross hematuria. Computerized tomography showed a solid mass at the lower pole of the left kidney. The patient underwent left nephrectomy. Histologically and immunohistochemically, the tumor was diagnosed as an inflammatory subtype of MFH. Histological appearances of inflammatory MFH vary widely and frequently overlap with benign reactive conditions such as Xanthogranulomatous pyelonephritis (XGPN) and malignant lesions, e.g. malignant lymphoma and, less frequently, a sarcomatoid variant of renal cell carcinoma. It is important, though difficult, to differentiate inflammatory MFH from these lesions. Careful morphological examination and immunohistochemical findings of the lesion are of great value, in particular in excluding it from its mimics. We discuss the pathological features and challenges involved in differentiating inflammatory MFH from its masquerader.     

Angiomatoid malignant fibrous histiocytoma

Summary The results of an histological, immunocytochemical and electron microscopic study of an angiomatoid malignant fibrous histiocytoma are reported. Our results support an histiocytic, rather than an endothelial origin for the tumor cells.     

Malignant fibrous histiocytoma of chest wall

Primary malignant fibrous histiocytoma (MFH) of the chest wall is rare. We report a case of primary MFH arising from the chest wall, which was thought to be a metastasis or myeloma. The imaging study revealed a single mass of the chest wall involving a rib. Resection and chest wall reconstruction was done. The histologic diagnosis was storiform-pleomorphic primary MFH. Although MFH of the chest wall is an uncommon pathology, it should be considered in the differentiation of a single bony destructive lesion involving the rib with a soft tissue component.     

An ultrastructural study of malignant fibrous histiocytoma of the larynx

Malignant fibrous histiocytoma (MFH) of the vocal cord occurring in a 46-year-old male was studied immunohistochemically and ultrastructurally. The tumor consisted of the two main areas, pleomorphic and storiform. Immunohistochemical staining was strongly positive for α1-antitrypsin and α1-antichymotrypsin, and negative for desmin, keratin, myoglobin, actin, carcinoembryonic antigen, and S100 protein. Ultrastructurally, this MFH consisted of four different types of cells which were either fibroblast-like, histiocyte-like, myofibroblast-like, or with features of both the fibroblast and histiocyte types. Transition forms between the four types of cells were also found. This suggests that cells of MFH are derived from the same undifferentiated stem cells.     

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.     

Primary pleomorphic malignant fibrous histiocytoma of the heart

Primary pleomorphic malignant fibrous histiocytoma of the heart is rare. The present study was performed to study the clinical and pathological features of the disease. We describe two rare cases of primary cardiac malignant fibrous histiocytoma and review the published individual data of the patients. Both patients complained of dyspnea, and underwent palliative tumor resection. However, they died several months after surgery. A thorough literature review with clinical presentations, diagnostic features, treatment, and outcomes was done. We have for the first time analyzed the factors related to the survival of malignant fibrous histiocytoma. It is usually difficult to make an appropriate preoperative diagnosis. Despite complete surgical resection and aggressive chemotherapy and radiotherapy, the prognosis is still poor.     

Primary malignant fibrous histiocytoma of the spleen: an ultrastructural study

A primary malignant fibrous histiocytoma of the spleen was studied by light and electron microscopy and is believed to be the first reported. The neoplasm was predominantly fibroblastic, with a characteristic storiform pattern, and included histiocyte-like cells, giant and foam cells confirmed by ultrastructural studies. Additionally, undifferentiated cells, intermediate cells and myofibroblasts were seen. The differential diagnosis from other sarcomas and the histogenesis of this tumour are discussed.