. The elements of pathological histology with special reference to practical methods . cts the uppersegment of the tympanic cavity (into which the epidermis can passthrough apertures in Shrapnels membrane), and the mastoid inflanmiation occur, whether it be acute or chronic, this dermiswill shed lamellae of epithelium, which become encased one inside theother like the scales of an onion, and may at last completely fill upthe tympanic cavity, including its upper segment, and the antrum.^ ^ The supposition (which is certainly authorised) may also be borne in mindhere, that the adva
. The elements of pathological histology with special reference to practical methods . cts the uppersegment of the tympanic cavity (into which the epidermis can passthrough apertures in Shrapnels membrane), and the mastoid inflanmiation occur, whether it be acute or chronic, this dermiswill shed lamellae of epithelium, which become encased one inside theother like the scales of an onion, and may at last completely fill upthe tympanic cavity, including its upper segment, and the antrum.^ ^ The supposition (which is certainly authorised) may also be borne in mindhere, that the advance of the epidermis to the tympanic mucous membrane maygive the first impulse to the formation of primary carcinoma of the tympaniccavity. CHOLESTEA TOM A 429 In such a manner are formed collections to which the namecholesteatoma has been given. They consist principally of polygonalcells, partly nucleated and partly non-nucleated, which far surpassthe cells of the epidermis in size, and between which are found fat-droplets. In addition to these they are partly composed of embedded. Fig. 216.—Frontal Vertical Section through the Internal Wall of the Tym-panum IN THE Region of the Aqueduct of Fallopius, in tubercular inflammation ofthe Middle Ear, x 25. (Hsematoxylin and eosin.) a, Mucous membrane of the internalwall of the tympanum, transformed into caseating granulation tissue ; 6, Bone ; c, Facialnerve, infiltrated with round cells ; d, Very greatly thickened sheath of the facial nerve,broken through by round-celled tissue in places. cholestearin crystals, and sometimes elongated giant cells of irregularshape and extraordinary size, having many large nuclei, are containedin them. In the central parts, which are usually broken downinto crumbling masses, there can in most cases be recognised, besidesthe formed constituents mentioned, detritus, micro-organisms, crystalsof margaric acid, or, though but very rarely, pus-corpuscles. Thecones of epidermis which often push into the
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectpatholo, bookyear1895
