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Results for “myxoid matrix”

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8 recordsLinked to original sources

PubMed1977

Atypical fibrous histiocytoma of the humerus: a light and electron microscopic study.

A unique osseous tumor, which arose in the humerus of a 44-year-old white man, is reported. The lesion was designated atypical fibrous histiocytoma because of the absence of atypical mitoses despite prominent nuclear pleomorphism of tumor cells. The tumor was composed mainly of spindle cells, tightly packed in a storiform pattern. Clear histiocytes and tumor giant cells were occasionally seen. Toward the proximal and distal ends, the tumor showed increasing fibrogenesis, and the ends were composed of areas of packed clear histiocytes and acellular myxoid matrix with focal calcification. Ultrastructurally, five cell types comprised the tumor, but fibroblast-like cells predominated. Histiocyte-like, xanthomatous, giant and undifferentiated cells were observed only occasionally. The patient has been followed for five years after disarticulation without developing evidence of distant metastasis.

Adult↗

PubMed1979

An unusual neoplasm of adipose tissue in a rat.

The light microscopic features of a spontaneous neoplasm of adipose tissue from a rat were suggestive of a mixed liposarcoma with a myxoid matrix. However, ultrastructurally, the cell characteristics were those of a hibernoma. These characteristics included cells containing lipid droplets of variable size, numberous pleomorphic mitochondria and close apposition to blood vessels. Lipofuscin granules and subplasmalemmal condensations were not observed ultrastructurally.

Adipose Tissue↗

PubMed2026

Primary Cerebral Pleomorphic-Myxoid Sarcoma With Many Hyaline Globules.

A case of primary sarcoma that arose in the right temporal lobe of a 59-year-old man is reported. The patient had a history of resection of a "pituitary tumor" and postoperative radiotherapy about 40 years earlier. The cerebral tumor consisted of loose and diffuse proliferation of large pleomorphic cells in a matrix showing a markedly myxoid change and containing a variable amount of delicate collagen fibers. Some tumor cells had a large intracytoplasmic vacuole containing acid mucopolysaccharide, thus featuring "pseudolipoblasts." Differentiation along other specific mesenchymal lineages was not found. Many tumor cells contained densely eosinophilic hyaline globules in the cytoplasm. Tumor cells showed a loss of the nuclear expression of H3K27me3. Although cerebral sarcomas showing similar histopathological features have not been previously reported, a markedly myxoid change of the stroma admixed with delicate collagen fibers and "pseudolipoblasts" suggests a close pathological kinship to myxofibrosarcoma. Another notable finding was the appearance of many hyaline globules, which has been considered a characteristic finding of primary intracranial sarcoma, DICER1-mutant. In the cytogenetic study of the present case, however, no DICER1 gene mutations were demonstrated.

Humans↗

PubMed1977

Myxoid variant of malignant fibrous histiocytoma.

It has been generally recognized that malignant fibrous histiocytoma (MFH) may assume a highly myxoid, hypocellular appearance. Eighty cases of malignant fibrous histiocytoma having varying degrees of myxoid change were reviewed. These tumors typically arose on the extremities (leg, 61%; arm, 21%) of adults (peak age incidence, 60-69 years). They were usually attached to fascia (31%) or involved skeletal muscle (51%) and had a mucoid or translucent appearance. The myxoid areas consisted of widely spaced spindled and pleomorphic cells embedded in a matrix of acid mucopolysaccharides. The cellular areas were indistinguishable from those of the typical pleomorphic MFH. The rate of local recurrence of these tumors was 61%, and of metastasis, 23%, but metastasis was less likely when the tumor was small, superficially located, or had a prominent myxoid component. In fact, the degree of myxoid change was inversely related to the rate of metastasis. Therefore, because of the more favorable prognosis of the myxoid variant, it seems appropriate to separate it from the usual nonmyxoid form of MFH. The myxoid variant must also be clearly distinguished from benign myxoid lesions such as myxoma or nodular fasciitis, with which it is often confused.

Adult↗

PubMed1976

Types of mesenchymal reactions in the carcinoma of uterine cervix.

In the cervical cancer stroma three essential types of mesenchymal reaction: myxoid, fibrogenic with angioplasia and fibroblastic low-differentiated were disclosed. The border membrane of cancer foci is composed of fibroblast layer and ground substance abundant in Ac-MPS of the hyaluronic acid type. This substance is the basal immunosuppressive factor of cancer cells in situ (TIS). Similar activity is exhibited by the pathologic mesenchymal proteins of fibrynoid and hyaline type. The level of chemical differentiation of the mesenchyma, changes according to the maturity of cellular factor in connective tissue. Ac-MPS of the hyaluronic acid type prevail in the ground substance of the myxoid and fibroblastic mesenchyma, while the substances containing sulfuric groups predominate in the tissue matrix exhibiting fibrogenic tendencies.

Adenocarcinoma↗

PubMed1978

Carcinoma of the breast with metaplasia to chondrosarcoma: a light and electron microscopic study.

Two carcinomas of the breast containing large areas of sarcomatous tissue were studied by light and electron microscopy. In one of these, the sarcomatous element was frankly cartilaginous and in the other, predominantly myxoid but with small cartilaginous-looking foci. By light microscopy, a highly suggestive metaplastic transition could be traced from cells within the epithelial nests to those within the sarcomatous lobules. Ultrastructurally, cells in the former region showed epithelial characteristics and those in the latter region, mesenchymal and/or cartilaginous features. The carcinomatous cells contained desmosomes and formed intercellular spaces lined by microvilli; a few cells showed prominent profiles of rough endoplasmic reticulum. In the first case, the cells in the immediate vicinity of the epithelial nests and those in the fully developed cartilaginous regions showed a progressive dilatation of their endoplasmic reticulum to form large sac-like structures filled with a finely granular and floccular material. The intercellular matrix was electron lucent and contained scattered dense particles, fibrillo-granular material and collagen fibres. Condensation of this material at some distance from the cell resulted in the formation of lacunae. In the second case, the cells in the myxoid areas also showed prominent dilatation of endoplasmic reticulum.

Breast Neoplasms↗

PubMed1976

Ultrastructure of the so-called "chordoid sarcoma". Evidence supporting cartilagenous differentiation.

A rare, distinctive neoplasm occurring in the soft tissue of the extremities and resembling chordoma has been recently described and variously termed "chordoid sarcoma," "chordoid tumor," and "parachordoma." An example of this tumor occurring in the flank is presented. The tumor lacks the ultrastructural features associated with chordomas. Moreover, the tumor appears to be elaborating an abundant matrix of sulfated acid mucopolysaccharide interspersed with collagen fibers in varying stages of maturation. These features suggest that the tumor is exhibiting chondroid, rather than chordoid, differentiation. Previous reports of extraskeletal myxoid chondrosarcoma bear a striking light microscopic and electron microscopic similarity to the "chordoid sarcoma," suggesting that the latter is a variant of extraskeletal myxoid chondrosarcoma.

Cells↗

PubMed1979

A comparative study including ultrastructure of intramuscular myxoma and myxoid liposarcoma.

The clinicopathological data of ten intramuscular myxomas (IMM) and three myxoid liposarcomas (MLS) are presented with emphasis on their ultrastructure. Electron microscopy of three of the IMM demonstrated the principal cell of the IMM to be similar to a fibroblast with prominent R.E.R., well-developed Golgi apparatus and cytoplasmic filaments. Intracytoplasmic lipid droplets were very rare. The matrix was composed of finely granular material, collagen fibers, fibrils and few capillaries. In contrast with the IMM, the cytoplasm of the MLS contained extensive lipid droplets. Capillaries were very abundant and in close proximity to the lipoblasts. The distinction between an IMM and MLS is usually clear-cut by light microscopy. Dissimilar ultrastructural features provide additional data to separate these two tumors. Ultrastructure confirmed Enzinger's impression that the cell of origin of the IMM is similar to a fibroblast with features that support the hypothesis that these cells are the source of production of the excessive amount of mucopolysaccharides in the matrix.

Adult↗