The diagnosis of gastroduodenal Crohn's disease by endoscopic biopsy.

Forceps endoscopic biopsy under direct vision is a useful tool in the diagnosis of gastroduodenal Crohn's disease. The presence of the characteristic microgranuloma is conclusive for diagnosis and was found in 33.3% of the cases. Biopsies should be taken from endoscopically pathologic and normal mucosa. The value of repeated endoscopic biopsy and serial sections in increasing the yield of granuloma is still uncertain. In the absence of granuloma the constellation of histopathologic changes such as mucosal oedema, inflammation, crypt abscess, erosion, ulceration, attenuated deformed duodenal villi and lymphangiectasia should be consistent with the diagnosis of Crohn's disease.