Keloid

Keloid (from Greek chele-claw of a crab and eidos-resembling), a variety of skin scar, the peculiarity of which is that the total amount of scar tissue formed here is greater than usual, so that the scar sometimes takes on the character of a tumor of the desmoid type or a dense fibroma (see). Such scars rise above the level of the surrounding skin, have a whitish, somewhat shiny appearance and are very dense to the touch. Sometimes a fine vascular network is visible on their surface. Upon microscopic examination of fresh, unripe (pinkish) K., one finds abundant development of young connective tissue, in which the abundant number of young, protoplasm-rich fibroblasts attracts attention; their close proximity and parallel arrangement at first glance resemble spindle cell sarcoma; later the number and richness of cells decrease, considerable disorder appears in their arrangement, and cell strands form a kind of braid; finally, among the cells, hyaline masses appear either in nodules (nodular keloidosis) or in strands (diffuse keloidosis). In conclusion, the mass of K. appears under the microscope as a close interweaving of dense hyaline beams or nests, among which are located strongly compressed, barely noticeable, as if naked cell nuclei. A feature of K., both formed and immature, is its extreme poverty in blood vessels; the amount of elastic tissue is also negligible. At the border with healthy tissues, a fan-like divergence of the hyaline strands of K. is noted. The usual site of development of K. is the skin at the site of former furuncles, acne, at the site of various wounds, burns and even after treatment with tincture of iodine. Similar K. formations are apparently also observed in internal organs: thus, Schridde describes K. in the lungs and bronchial glands in pneumoconioses (in Ruhr stonecutters) on the basis of developing indurative-sclerotic changes here. Considerable similarity and even identity with K. can be found in the edges of chronic gastric ulcers (ulcus callosum; Schridde suggests calling such cases ulcus keloidosum), scars of the vermiform appendix during its inflammation, etc. Ceteris paribus K. develops only in some individuals predisposed to keloidosis (Schridde); thus, out of thousands of examined lungs of Ruhr miners, Schridde found keloid scars of the lungs and lymph glands only in individual cases. - In addition to the described scar (secondary) K., there are also so-called true K., which arise on the skin completely independently of any previous damage or defects in it; however, some authors dispute this. Resembling scar K. in appearance and consistency, true K. may be either single or multiple and may be located on any part of the body, but more often appear on the chest. Sometimes these are limited, sharply protruding nodules of round or band-like shape, the color of the skin or more pink-red in color, sometimes large flat tumors with a crimson hue, showing a tendency to merge, thereby acquiring bizarre, branching, crab-claw-like outlines. Hair and openings of sebaceous and sweat glands are preserved. True K. never ulcerates and shows moderate growth. As a rule, K. does not cause subjective sensations, but occasionally there can be severe, neuralgic pains. The cause is unknown. In some cases, the history reveals congenital syphilis. In the black race, true K. occurs more frequently. - T r e a t m e n t. Previously, K. was treated surgically (excision), but it should be borne in mind that removed K. almost always recur, which forced the search for other methods, of which many have been proposed: thermocautery, injection into the thickness of K. of a 20% solution of creosote oil, 5-10% solution of thionamine (very painful), etc. In recent times, iodine ionization has also been used with some success.