glycogen and Histiocytoma--Benign-Fibrous

Topics: Biomarkers, Tumor; Cytoplasm; Female; Glycogen; Histiocytoma, Benign Fibrous; Humans; Immunohistochemistry; Leg; Microscopy, Electron; Middle Aged; Soft Tissue Neoplasms; Terminology as Topic

Light and electron microscopic observations were made on eosinophilic globule (EG) cells found in 27 subcutaneous malignant fibrous histiocytoma (MFH)-like sarcomas in aged ICR mice. These tumors, which were composed of fibroblast-like cells as the major component, with small numbers of histiocyte-like cells and undifferentiated cells, showed one or more of five growth patterns: storiform, pleomorphic, fascicular, myxoid, and hemangiopericytoma-like. EG cells were interspersed among the tumor cells and were also present in metastatic lesions. They were pleomorphic in shape and contained various numbers of cytoplasmic globules, which were positive with the periodic acid-Schiff reaction and resistant to diastase digestion. Electron microscopic observation revealed that these cells had small finger-like and pseudopodia-like projections, and contained varied numbers of characteristic osmiophilic globules and glycogen particles in the cytoplasm which seemed to become more abundant as the cells differentiated. The osmiophilic globules consisted of a dense homogeneous core and a marginal area rich in small vesicular membranous structures. A small population of EG cells exhibited features suggesting differentiation to fibroblasts; these were characterized by an increased amount of rough endoplasmic reticulum. It is suggested that the EG cell is a neoplastic cell, perhaps derived from a primitive mesenchymal cell, although an inflammatory cell origin is also possible.

Topics: Animals; Cell Differentiation; Cytoplasm; Endoplasmic Reticulum; Female; Fibroblasts; Glycogen; Histiocytes; Histiocytoma, Benign Fibrous; Histocytochemistry; Male; Mice; Mice, Inbred ICR; Microscopy, Electron; Necrosis; Periodic Acid-Schiff Reaction; Sarcoma, Experimental

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.

Topics: Cytoskeleton; Endoplasmic Reticulum; Glycogen; Histiocytes; Histiocytoma, Benign Fibrous; Humans; Liposarcoma; Microscopy, Electron; Rhabdomyosarcoma; Soft Tissue Neoplasms

An ultrastructural comparison of 7 examples of myxoid malignant fibrous histiocytoma (myxoid MFH) with 6 of myxoid liposarcoma is described. Despite certain histological differences between the two, electron microscopy was more valuable in differentiating MFH from liposarcoma. Electron microscopically, MFH contained a variety of cell types including histiocyte-like, fibroblast-like, intermediate-type, xanthomatous, multinucleated tumor giant cells and undifferentiated cells. Liposarcoma was composed mainly of lipoblasts at various stages of differentiation with a minority of undifferentiated cells and fibroblast-like cells. In contrast to the component cells of the MFH, these lipoblasts were characterized by abundant cytoplasmic glycogen, numerous pinocytotic vesicles and a discontinuous basal lamina in addition to large lipid droplets.

Topics: Adult; Aged; Arm; Female; Fibroblasts; Glycogen; Histiocytes; Histiocytoma, Benign Fibrous; Humans; Liposarcoma; Male; Microscopy, Electron; Middle Aged; Pinocytosis; Thigh

A malignant fibrous histiocytoma (MFH) arising in the lungs of a 51-year-old man was studied by light and electron microscopy. Features observed were identical to those of MFHs which occur in the skin and subcutaneous tissue and less commonly in other deep locations. By light microscopy, a storiform pattern with admixture of fibroblasts and histiocytes, as well as xanthomatous and giant cells, was noted. Undifferentiated tumor cells along with fibroblasts and histiocytes in different degrees of differentiation were identified ultrastructurally. These findings lend support to the concept that MFH is a sarcoma of primitive mesenchymal cell origin. The addition of the lung as another primary site for the development of this tumor is consistent with the view that MFHs may potentially arise in any part of the body.

Topics: Cytoplasm; Endoplasmic Reticulum; Fibroblasts; Glycogen; Histiocytes; Histiocytoma, Benign Fibrous; Humans; Lung Neoplasms; Lysosomes; Male; Microscopy, Electron; Middle Aged; Necrosis