Elastofibroma Dorsi

Abstract

Two unusual tumors of the subscapular soft tissues were encountered in elderly Japanese women. These were composed of fibrous tissue and fibers having the tinctorial characteristics of elastic fibers. They seemed to be identical with 5 similar tumors recently described by Jarvi and Saxen, who gave them the name elastofibroma dorsi to indicate their constituents and site of origin. Histochemical studies suggest that the fibers in these tumors which take the elastic tissue stain have 2 constituents. One of these is a matrix composed of reticulin fibers which resists elastase digestion. This matrix surrounds a central space. Both the matrix and the space are impregnated with a material which stains as elastin and which is sensitive to elastase digestion. The study did not reveal the etiology of the tumors but did suggest that they might result from elastotic degeneration of collagen.