From Big Medical Encyclopedia


bile - j-stear, steatos fat, fat - j - oma; synonym: an epidermoid cyst,

epidermoid, a pearl tumor) — the heterotopic tumor of dizontogenetiche-Skye coming from the rudiments of epidermis displaced in a head cavity or the vertebral channel in the early period of embryonic development.

Intracranial and spinal cholesteatomas should be distinguished from false or secondary cholesteatomas, to-rye develop as a result of growth of epidermis on average to fish soup at a long inflammation (see the X olesteatom of an ear). Also nostgkhunktsionny cholesteatomas of a spinal cord which developed as a result of the shift of epidermis during repeated spinal punctures are described.

Cholesteatomas of a brain meet more often at men aged from 20 up to 40 years. The cholesteatoma of a spinal cord is observed preferential at children, sometimes in combination with malformations of a nervous system. Intracranial cholesteatomas preferential in the field of a mostomozzhechkovy corner, the Turkish saddle and hiazmalny area are localized; much less often cholesteatomas are located in one of side ventricles or in a cavity of the fourth ventricle, is even more rare in bones of a skull, growing in nek-ry cases into a head cavity. Sometimes the intracranial cholesteatoma destroys an internal plate of a bone. The vertebral channel of a cholesteatoma can be located in an epidural space, in a soft cover of a spinal cord and extremely seldom intrame-dullyarno. Cholesteatomas of a head and spinal cord most often proceed from a soft meninx (see the Meninx), and in cases of intra ventricular localization — from a stroma of a vascular texture of a ventricle (see. Vascular textures).

The cholesteatoma usually has an appearance of a single node of incorrectly rounded shape with an uneven chicken skin. Seldom the tumor consisting of two and more nodes meets. Color of a tumor white, with characteristic nacreous,-nominayushchim on pearls, gloss, to-ry quickly disappears iod influence of air. Macroscopically it is single-chamber, the multichamber cyst with the white lamellar brittle contents consisting of the keratosic epithelial cells and crystals of cholesterol giving to weight a grease look is more rare.

Microscopically the capsule of a cholesteatoma consists of two layers: outside, formed by a thin coat of fibrous connecting fabric, and internal — thin layer of a multilayer flat epithelium. The periblast is usually densely soldered to adjacent marrow and sometimes contains infiltrates from lymphocytes and plasmocytes. The inner layer corresponds to the reduced structure of the epidermis consisting of one-two rows of cells of rostkovy, granular and horn layers. When the keratosic masses directly prilezhat to a periblast, in it the chronic productive inflammation develops.

The wedge, a picture of a cholesteatoma depends on its localization. Cholesteatomas grow slowly, fill subarachnoid tanks of a brain or are pressed into substance of a brain, densely growing together with it. At intra ventricular localization the cholesteatoma grows together with walls of ventricles. The productive inflammation developing around a cholesteatoma can sometimes lead to fusion of a silviyev of a water supply system (see the Brain). The cholesteatoma of a mostomozzhechkovy corner is shown by the trunk and cerebellar disturbances more expressed on the party of a tumor (see the Mostomozzhechkovy corner). Often the disease is followed by intracranial hypertensia of occlusal character. At a cholesteatoma of a spinal cord symptoms of irritation and a prelum of a spinal cord (see), characteristic for ekstramedullyarno the located tumors are observed.

At cholesteatomas the course of process slow, high-quality, its duration is quite often estimated many years. Isolated cases of development of planocellular cancer from a cholesteatoma are described. Treatment operational. During incomplete removal the recurrence of a cholesteatoma is possible. Development after the operational aseptic pia-arachnitis caused by toxic influence of contents of a cholesteatoma is possible.

Bibliography: The multivolume guide to pathological anatomy, under the editorship of.

A. I. Strukova, t. 2, page 376, M., 1962;

Janisch W., Guthert H. u. Schreiber D. Pathologie der Tumo-ren des Zentralnervensystems, S. 246, 304, Jena, 1976; Russell D. Rubinstein L. J. Pathology of tumors of the nervous system, p. 30, 220, L., 1977.

S.Yu. Kasumova.