[Whipple disease with negative duodenal histology--a case report and review of the literature].

The arthritis of Morbus Whipple is an early clinical manifestation of this rare disease. As the arthritis precedes the gastrointestinal symptoms, very often it is an important early diagnostic clue in this potentially fatal disease. The classical method in establishing the diagnosis is to show the characteristic histologic features in the affected tissues or in small bowel biopsy. Employed in the latter are usually multiple directed biopsies during duodenal endoscopy. This case report gives an example that the duodenum may be spared during active Whipple's disease and even affected tissues must not show the characteristic features of Morbus Whipple.