Biomaterial Database

Malignant schwannomas presenting as malignant fibrous histiocytomas. 1982

G A Herrera, and B E Reimann, and J A Salinas, and E A Turbat

Two soft tissue neoplasms considered to represent malignant fibrous histiocytomas by light microscopy showed typical findings indicative of Schwann cell origin when examined by electron microscopy. These findings included the presence of cells exhibiting long interdigitating cytoplasmic processes, which frequently contained collections of microtubules and were surrounded by thin, frequently interrupted, basal lamina material. In addition, pinocytotic activity at the cell surfaces and immature junctions joining apposing cellular membranes were identified. No evidence of fibroblastic, fibrohistiocytic, or myofibroblastic differentiation was identified ultrastructurally in the neoplastic cells. Our findings stress the need for ultrastructural examination to adequately classify soft tissue sarcomas. The 2 cases presented illustrate that there are some schwannomas that may be inaccurately classified as malignant fibrous histiocytomas if only light microscopy is used. It seems that only by ultrastructural means is it possible to accurately classify these peculiar neoplasms.

UI	MeSH Term	Description	Entries
D007365	Intercellular Junctions	Direct contact of a cell with a neighboring cell. Most such junctions are too small to be resolved by light microscopy, but they can be visualized by conventional or freeze-fracture electron microscopy, both of which show that the interacting CELL MEMBRANE and often the underlying CYTOPLASM and the intervening EXTRACELLULAR SPACE are highly specialized in these regions. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p792)	Cell Junctions,Cell Junction,Intercellular Junction,Junction, Cell,Junction, Intercellular,Junctions, Cell,Junctions, Intercellular
D008297	Male		Males
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008870	Microtubules	Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.	Microtubule
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D009442	Neurilemmoma	A neoplasm that arises from SCHWANN CELLS of the cranial, peripheral, and autonomic nerves. Clinically, these tumors may present as a cranial neuropathy, abdominal or soft tissue mass, intracranial lesion, or with spinal cord compression. Histologically, these tumors are encapsulated, highly vascular, and composed of a homogenous pattern of biphasic fusiform-shaped cells that may have a palisaded appearance. (From DeVita Jr et al., Cancer: Principles and Practice of Oncology, 5th ed, pp964-5)	Neurinoma,Schwannoma,Schwannomatosis, Plexiform,Neurilemoma,Neurilemmomas,Neurilemomas,Neurinomas,Plexiform Schwannomatoses,Plexiform Schwannomatosis,Schwannomas
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D003593	Cytoplasm	The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Protoplasm,Cytoplasms,Protoplasms
D003937	Diagnosis, Differential	Determination of which one of two or more diseases or conditions a patient is suffering from by systematically comparing and contrasting results of diagnostic measures.	Diagnoses, Differential,Differential Diagnoses,Differential Diagnosis