A case of esophageal sarcomatoid carcinoma with molecular evidence of a monoclonal origin

A case of polypoid tumor of the esophagus consisting of a sarcomatous tumor partly covered with superficial squamous cell carcinoma is described. The sarcomatous component consisted of anaplastic spindle and pleomorphic tumor cells that mimicked malignant fibrous histiocytoma (MFH). Both the sarcomatous and carcinomatous components were positive for p53 immunohistochemically. Further molecular analysis revealed that the two components had the same somatic mutation in the p53 gene. These results suggest a monoclonal origin of this biphasic tumor.     

Atypical fibrous histiocytoma of the scrotum

Atypical fibrous histiocytoma is a rare neoplasm. A scrotal location for this tumor is even more unusual. We report a case of a 90-year-old man with scrotal atypical fibrous histiocytoma. Our case had histologic features consistent with those cases previously reported in the literature. The tumor consists of cells with large hyperchromatic irregular nuclei, bizarre multinucleated cells (monster cells), and xanthomatous cells with large prominent nuclei set in a background of classic fibrous histiocytoma. Rare mitotic figures are identified. Immunohistochemical studies showed the tumor cells to be positive for vimentin, smooth muscle actin, desmin, KP-1, factor XIIIa, and MIB-1 (less than 10%). In addition to the expected immunohistochemical studies, the tumor stained diffusely positive for CD117. To our knowledge, this is the first report of atypical fibrous histiocytoma of the scrotum.     

Malignant fibrous histiocytoma of bone and osteosarcoma. A comparative light and electron microscopic study.

Malignant fibrous histiocytomas are well-described tumors of the soft tissues. Recent investigations have shown that malignant histiocytoma may also occur as a primary bone tumor. However, difficulties may arise to distinguish malignant histiocytoma of bone from other malignant bone tumors, such as osteosarcoma. In the present study, the ultrastructure of five cases of malignant fibrous histiocytoma of bone is compared with that of osteosarcoma. The results show that malignant fibrous histiocytoma is composed mainly of histiocytic cells and fibroblastic cells. In addition, xanthomatous cells, undifferentiated cells, and giant cells may be observed. By contrast, the predominant cell type in osteosarcoma is the neoplastic osteoblast, characterized by abundant rough endoplasmic reticulum. Signs of matrix calcification in the intercellular matrix between the collagen fibrils are regularly observed in osteosarcoma, but not in malignant histiocytoma. From these results it is concluded that the ultrastructure of malignant fibrous histiocytoma arising in bone is morphologically identical with the soft tissue counterpart of this tumor. The components of the tumor are derived from neoplastic histiocytes. This cytogenesis differs from that of osteosarcoma, which is derived from neoplastic osteoblasts. Therefore, from the ultrastructural point of view, malignant fibrous histiocytoma of bone should be accepted as a distinct histologic entity among bone tumors.     

Malignant fibrous histiocytoma arising in a recurrent chordoma

Summary We present the case of a sacrococcygeal chordoma which recurred 15 years after the radical removal as a soft tissue tumor in the gluteal musculature. This tumor consisted of two parts: a chordoma without symptoms of aggressive cellular proliferation and a malignant fibrous histiocytoma. During the following 4 years several local recurrences of the malignant fibrous histiocytoma occurred in the gluteal musculature. The patient finally died of lung metastases. No chordoma tumor tissue was found in the lungs, in the gluteal musculature or in the sacrococcygeal bone area. Histology including electron microscopy revealed no proof of a transition of chordoma into malignant fibrous histiocytoma. It must be assumed that the secondary soft tissue tumor originated from residual chordoma cells which were implanted during the operation of the primary tumor. It remains unclear whether the malignant fibrous histiocytoma arose from mesenchymal stromal cells within the chordoma or directly from primitive neuroectodermal chorda cells which possess the ability to differentiate into a variety of cell types including mesenchymal cells.     

Experimental approach to fibrous histiocytoma

A transplantable tumor was produced in syngeneic mice inoculated with transformed bone marrow macrophages (28-12- and L-18 cell lines). The tumor composed of proliferative spindle cells was arranged in a storiform pattern, and was similar to that of human fibrous histiocytoma. Electron microscopically, the tumorous spindle cells had fibroblastic characteristics, while functionally, the tumor cells had histiocytic characteristics, and consisted of a transitional form between histiocytes and fibroblasts. We consider the spindle cells to be facultative fibroblasts. This finding is compatible with the hypothesis that fibrous histiocytoma is derived from histiocytes.     

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.     

Acute Myopathy Associated with Chronic Licorice Ingestion: Reversible Loss of Myoadenylate Deaminase Activity

A case of recurrent soft part sarcoma with focal areas showing epithelial differentiation in the right thigh in a 78-year-old woman is reported. The primary tumor consisted of myxoid areas and solid areas, in which relatively uniform epithelioid tumor cells were arranged in sheets, whereas pleomor-phism and a storiform pattern appeared in the recurrent tumors. Thus this tumor was suspected to be a malignant fibrous histiocytoma. However, further studies showed unexpected ultrastructural and immunohistochemical features. Cytokeratin immu-noreactivity and tonofilamentlike structures probably indicated epithelial differentiation of some tumor cells. From the clinical and histological findings, this tumor should be identified as a malignant fibrous histiocytoma with phenotypic expressions of epithelial cell.     

Malignant Fibrous Histiocytoma with Epithelial Differentiation?

A case of recurrent soft part sarcoma with focal areas showing epithelial differentiation in the right thigh in a 78-year-old woman is reported. The primary tumor consisted of myxoid areas and solid areas, in which relatively uniform epithelioid tumor cells were arranged in sheets, whereas pleomor-phism and a storiform pattern appeared in the recurrent tumors. Thus this tumor was suspected to be a malignant fibrous histiocytoma. However, further studies showed unexpected ultrastructural and immunohistochemical features. Cytokeratin immu-noreactivity and tonofilamentlike structures probably indicated epithelial differentiation of some tumor cells. From the clinical and histological findings, this tumor should be identified as a malignant fibrous histiocytoma with phenotypic expressions of epithelial cell.     

Ultrastructural Heterogeneity in Malignant Fibrous Histiocytoma of Soft Tissue

Five soft tissue sarcomas with histological features of malignant fibrous histiocytoma were selected to illustrate their ultrastructural heterogeneity. One case displayed the mixture of fibroblastic and histiocytic cells characteristic of the majority of malignant fibrous histiocytomas. In 1 case the tumor was composed entirely of primitive mesenchymal cells. The other 3 cases showed lipogenic, neurogenic, and “granular-cell” differentiation, respectively. These findings emphasize the important role of electron microscopy in the precise diagnosis and classification of malignant fibrous histiocytoma.     

Ultrastructural Heterogeneity in Malignant Fibrous Histiocytoma of Soft Tissue

Five soft tissue sarcomas with histological features of malignant fibrous histiocytoma were selected to illustrate their ultrastructural heterogeneity. One case displayed the mixture of fibroblastic and histiocytic cells characteristic of the majority of malignant fibrous histiocytomas. In 1 case the tumor was composed entirely of primitive mesenchymal cells. The other 3 cases showed lipogenic, neurogenic, and “granular-cell” differentiation, respectively. These findings emphasize the important role of electron microscopy in the precise diagnosis and classification of malignant fibrous histiocytoma.     

Benign fibrous histiocytoma of the renal capsule.

The first case of benign fibrous histiocytoma of the renal capsule is reported in a male aged 44 years. The tumor had its point of origin in the renal capsule. Histologically, the tumor was composed of intersecting fascicles of fibroblastic cells forming a loose crisscross or "storiform" pattern. Electron microscopic studies of tumor cells revealed intermediate filaments and membrane-bound collagen fibers which continued to extracellular collagen bundles. This deep seated fibrous histiocytoma had a more prominent storiform pattern and fewer secondary elements such as xanthoma cells than cutaneous ones.     

Disseminated malignant fibrous histiocytoma (giant cell rich): a case report

Giant cell rich malignant fibrous histiocytoma accounts for 3 -15% of all malignant fibrous histiocytomas. Currently, the nomenclature giant cell malignant fibrous histiocytoma is reserved for undifferentiated pleomorphic sarcomas with prominent osteoclastic giant cells. It is considered to be synonymous with malignant giant cell tumor of soft parts. We report a case of disseminated giant cell malignant fibrous histiocytoma involving the scalp, cervical node, lungs, spine, abdominal wall, base of penis, gluteal cleft, paraspinal region and back. The diagnosis was established after staining for a panel of immunohistochemical markers namely cytokeratin, vimentin, S100, desmin, CD68 and smooth muscle actin. CD68 positivity in tumor cells helped in arriving at the final diagnosis. It is essential to recognize this tumor as a giant cell rich distinct entity and differentiate from other giant cell rich pleomorphic sarcomas since therapeutic and prognostic differences are being appreciated currently.     

Ultrastructural heterogeneity in malignant fibrous histiocytoma of soft tissue

Five soft tissue sarcomas with histological features of malignant fibrous histiocytoma were selected to illustrate their ultrastructural heterogeneity. One case displayed the mixture of fibroblastic and histiocytic cells characteristic of the majority of malignant fibrous histiocytomas. In 1 case the tumor was composed entirely of primitive mesenchymal cells. The other 3 cases showed lipogenic, neurogenic, and "granular-cell" differentiation, respectively. These findings emphasize the important role of electron microscopy in the precise diagnosis and classification of malignant fibrous histiocytoma.     

Experimental tumors of myxoid malignant fibrous histiocytoma and hyaluronic acid production

Using B-10 tumor cells originated from mouse peritoneal macrophages transformed by simian virus 40, we succeeded in producing tumors in an ascitic form similar to human myxoid malignant fibrous histiocytoma. The tumor cells possessed Fc and C3 receptors, immunophagocytic activity, and lysosomal enzymes. They showed pseudopodic extensions of the cytoplasm containing lysosomes. Therefore, they maintained the functional and morphological characteristics of macrophages. On cellulose acetate electrophoresis with or without enzymatic degradation, the ascitic fluid contained a single component of glycosaminoglycans; hyaluronic acid. Electron microscopy utilizing dialyzed iron demonstrated electron-dense reaction products on the cell surfaces. Thus, the histiocytic origin of malignant fibrous histiocytoma was suggested and possibility was expressed, concerning the histogenesis of myxoid malignant fibrous histiocytoma, that the transformed tumor cells could synthesize hyaluronic acid on the cell surface and release it into the stroma.     

Benign Fibrous Histiocytoma of the Renal Capsule

The first case of benign fibrous histiocytoma of the renal capsule is reported in a male aged 44 years. The tumor had its point of origin in the renal capsule. Histologically, the tumor was composed of intersecting fascicles of fibro-blastic cells forming a loose crisscross or "storiform" pattern. Electron microscopic studies of tumor cells revealed intermediate filaments and membrane-bound collagen fibers which continued to extracellular collagen bundles. This deep-seated fibrous histiocytoma had a more prominent storiform pattern and fewer secondary elements such as xanthoma cells than cutaneous ones. Acta Pathol Jpn 42: 217 220, 1992.     

Intracranial benign fibrous histiocytoma mimicking parasagittal meningioma: report of two cases and review of literature

Primary benign fibrous histiocytoma involving the central nervous system is an exceedingly rare tumor with most cases originating from the dura or parenchymal tissue. Diagnosis of primary benign fibrous histiocytoma is difficult due to its confusing histopathological characteristics. Two cases of primary intracranial benign fibrous histiocytoma mimicking parasagittal meningioma are presented in this report. Both tumors were gross totally resected and the patients showed no evidence of recurrence at follow-up of 12 months. The clinical features and prognosis of this rare tumor that were reported previously in the literature were also reviewed. Histopathological examination coupled with immunohistochemical staining is proved to be the convincing diagnostic method for the primary benign fibrous histiocytoma. Surgical resection is the recommendation for the therapy of the tumor.     

Chemically induced transplantable malignant fibrous histiocytoma of the rat. Analyses with immunohistochemistry, immunoelectron microscopy and [3H]thymidine autoradiography

Malignant fibrous histiocytoma was produced in rats by injection of 9,10-dimethyl-1,2-benzanthracene into their knee joints. The original tumors consisted mainly of fibroblast-like cells and histiocyte-like cells, often intermixed with bizarre giant cells, and they frequently showed the storiform-pleomorphic pattern. By immunohistochemistry, anti-rat macrophage monoclonal antibodies, TRPM-3, RM-1, and Ki-M2R, and anti-rat leukocyte common antigen reacted to the histiocyte-like cells but not to the fibroblast-like cells. By the single cell cloning method, we established six tumor cell lines, none of which reacted with the anti-rat macrophage monoclonal antibodies, possessed any Fc receptors, or conducted immune phagocytosis and Latex particle phagocytosis. The ultrastructure of the cloned tumor cells resembled that of long-term cultured dermal fibroblasts. Collagen production by the tumor cells was demonstrated immunohistochemically with a monoclonal antibody for type I collagen. Inoculation of the cloned tumor cells into rats produced tumors with the histology of malignant fibrous histiocytoma and induced prominent macrophage infiltration. In the rat tumors produced by the inoculation of [3H]thymidine labeled cells, no reactivity of tumor cells with the anti-rat macrophage monoclonal antibodies was observed. Transplantation of the cultured rat tumor cells into nude mice produced tumors similar in histology to the original rat malignant fibrous histiocytoma. Tumor cells in nude mice induced marked macrophage infiltration as detected by immunohistochemistry with the anti-mouse macrophage monoclonal antibody F4/80. No differentiation of tumor cells into macrophages was detected, since no cells were stained with biotinylated anti-rat macrophage monoclonal antibody TRPM-3. By the flash labeling method with [3H]thymidine, infiltrating macrophages in the nude mouse tumors were proved to derive from the bone marrow of the host animals. These results indicate a possible experimental reproduction of malignant fibrous histiocytoma by proliferation of malignant fibroblasts or their related cells in combination with macrophage infiltration.     

Aneurysmal (angiomatoid) fibrous histiocytoma of the skin: an unusual variant of dermatofibroma

We present a rare case of aneurysmal (angiomatoid) fibrous histiocytoma (AAFH) of the skin on the back of a 40-year-old Japanese man. Histologically, the tumor was characterized by massive proliferation of fibroblastic and histiocytic cells, prominent aggregation of hemosiderin pigment, and the presence of blood-filled tissue spaces devoid of an endothelial lining within a capillaryrich stroma. Immunohistochemically the tumor cells were immunoreactive for vimentin and for Factor XIIIa or Mac387. Ultrastructural study revealed that the tumor was composed mainly of fibroblast-like cells intermingled with histiocyte-like cells and intermediate cells with combined features of the two types of cells. These findings support the fibrohistiocytic origin of aneurysmal (angiomatoid) fibrous histiocytoma. In addition, ultrastructural examination seems quite useful to differentiate from other cutaneous neoplasms with architectural and cytological similarities to this tumor.     

Malignant fibrous histiocytoma of bone. Clinical pathology and histological diagnosis

Malignant fibrous histiocytoma of bone is a histologically well-defined tumor. Our aim is to describe five own cases and to analyze the published cases in order to demonstrate, the controversial aspects of clinical pathology. The essential histological criteria are the storiform tissue pattern and the presence of fibroblastic and histiocytic cells and giant cells. Inclusive of our cases, the total number reported stands at 196. There are features of malignant fibrous histiocytoma of bone about which there is almost general agreement: 1. The tumor occurs at all ages with an average onset from the age of 10 to the age of 50. 2. The tumor occurs in both the long and flat bones, but the main sites are the distal femur and the proximal tibia. 3. The tumor lacks any initial distinctive features in its clinical phase, but with respect to its biological behaviour, malignant fibrous histiocytoma of bone can be distinguished from osteosarcoma.