Diagnostic utility of the polymerase chain reaction in 2 cases of suspected Whipple disease.

We describe 2 patients with a diagnosis of Whipple disease in whom the usual antibiotic therapy failed. A polymerase chain reaction-based test was used to identify the recently described Whipple bacillus, Tropheryma whippelii. In one case, the diagnosis was confirmed, whereas in the second case, which had been histologically diagnosed as Whipple disease of the brain, the process was identified as a monocyte-derived histiocytosis. In conclusion, Whipple disease can be distinguished from other diseases with similar histological features with the use of a polymerase chain reaction-based test.