[Aphthous ulcers--an early radiological sign of Crohn's disease? (author's transl)].

Thirty-eight patients with histologically confirmed Crohn's disease are described. Eleven of these showed so-called aphthous ulcers. These were most common in the colon (five patients) and terminal ileum (four patients). Aphthous ulcers are small mucous membrane erosions on the surface of hypertrophic lymph follicles with surrounding oedema. From our material and from the literature we conclude that aphthous ulcers are occasional radiological signs and not invariable early signs of Crohn's disease. Their specificity has not been proved. Differentiation from gastric erosions in cases of gastro-duodenal involvement is discussed.