From Big Medical Encyclopedia

LIPOSARCOMA (liposarcoma, grech, lipos fat + sarcoma) — the malignant tumor developing from fatty tissue .

On a structure of L. can remind embryonal, fetalis or mature fatty tissue. L. from embryonal fabric has the thin semi-translucent capsule, a student invisible consistence, grayish color with dark red streaks; other H.p. badly expressed capsule, more dense consistence, yellowish color, from tyazha of connecting fabric, the centers of a necrosis and hemorrhages.

Microscopic picture of various options of a liposarcoma. Fig. 1. High-differentiated: among lipoblasts growths of fibrous fabric with single atypical cells are visible (are specified by shooters); x 200.
Microscopic picture of various options of a liposarcoma. Fig. 2. Myxomatous: accumulation of otrostchaty lipoblasts (1) around capillaries, single cricoid cells are visible (2); x 100.
Microscopic picture of various options of a liposarcoma. Fig. 3. Kruglokletochny: lipoblasts with one or several vacuoles in cytoplasm are visible (are specified by shooters); X 200.
Microscopic picture of various options of a liposarcoma. Fig. 4. Polymorphic: polymorphic cells with huge kernels of a bizzare shape (1) and fatty vacuoles in cytoplasm (2) are visible; X 200.

Microscopically L. consist of the cells which are at various stages of a differentiation of a lipoblast: usual lipoblasts; small otrostchaty and oval with monomorphic kernels, containing a glycogen in cytoplasm; large polymorphic cells with big kernels of the bizzare shape and cytoplasm containing single fatty vacuoles and deprived of a glycogen. Figures of a mitosis in fabric L. meet seldom.

Large tumor cells lie usually closely to each other; cells like lipoblasts, especially otrostchaty and extended, are located rykhlo in loops of a capillary network and in the myxomatous basis rich hyaluronic to - that. Growths of connecting fabric in L. meet in the form of uneven layers and wide fields. At gistokhy. a research in fabric L. small activity of esterase, an acid and alkaline phosphatase is defined.

It agrees gistol, WHO classifications of 1969, distinguish high-differentiated by L. (synonym: a polymorphonuclear lipoma, a polymorphonuclear fibrolipoma, sclerosing a lipoma), myxomatous L. (synonym embryonal lipoma), kruglokletochny L. (synonym: adenoid lipoma, lipoma infiltrative and fetalis and cellular, lipoblastichesky sarcoma) and polymorphic L. (synonym: true L., lipotsitarny sarcoma) (fig. 1 — 4).

L. can be multiple and meet in various areas of a body, however it is noticed that the favourite localization high-differentiated by L. retroperitoneal cellulose is, myxomatous L. — intermuscular fatty tissue of a hip and shin. L. usually slowly grow and seldom metastasize; cases of hematogenous innidiation in lungs, a liver, marrow at myxomatous and polymorphic types L are described.

Treatment operational or combined (removal of L. in combination with radiation therapy).

Forecast to thicket adverse, after treatment there comes a recurrence.

Bibliography: Vikhert A. M., and l and Oglou G. A. l iporoshin K. K. Tumors of soft tissues, page 34, 43, M., 1969; Lavnikova G. A. Some histochemical data on embryonal lipomas, Arkh. patol., t. 28, No. 5, page 30, 1966; The International histologic classification of tumors, No. 3 — Entsinger F. M. Histologic classification of tumors of soft tissues, M., WHO, 1974; The Guide to pathoanatomical diagnosis of tumors of the person, under the editorship of N. A. Krayevsky and A. V. Smolyannikov, page 37, M., 1976, bibliogr.

G. A. Lavnikova.