[Frequency and pathogenesis of epitheloid cell granuloma in Crohn's disease (author's transl)].

12% of the rectal biopsies (19% of the patients) showed epitheloid cell granulomas in clinically definite Crohn's disease. In colonic biopsies such granulomata were visible in 14% (22% of the patients). Granulomata were scarcely seen in normal or slightly inflamed mucosa. They were mostly found together with crypt abscesses and/or erosions and ulcers. The combination of local inflammation around crypts and crypt abscesses is rather characteristic for Crohn's disease. The inflammatory colonic alterations, visible in crohon's disease, may have the following pathogenetic sequence: Local colitis-crypt abscess--destruction of the crypt with proliferation of enlarged histiocytes--transformation histiocytes to epitheloid cells and Langhans cells--epitheloid cell granuloma.