[Submucosal presentation of Whipple's disease: a variant that is easily missed].

Whipple's disease is a multisystem, and often chronic, disease caused by infection with the bacterium Tropheryma whipplei, and mainly occurs in middle-aged Caucasian men. In most cases, histological detection of large numbers of bacteria-laden macrophages in the mucosa of the small intestine confirms the diagnosis. Less commonly, these macrophages may be sparse and predominantly located beneath the mucosa. In these submucosally presenting cases, endoscopic and classic histological clues are absent and, therefore, the diagnosis can be missed. As a result, further periodic acid-Schiff (PAS) staining and PCR analysis are of great importance in arriving at the correct diagnosis.