Epithelioid cell granulomata in the mucosa of the small intestine in Whipple's disease.

This report is the first description of sarcoid-like epithelioid cell granulomata in the mucosa of the small intestine in a case of Whipple's disease. The epithelioid cells do not contain PAS-positive material or products of bacterial degradation. Their ultrastructural features characterize them as histiocytes which have become secretory rather than phagocytic. These sarcoid-like lesions are considered to be a morphological manifestation of an immunological process in Whipple's disease and not to represent evidence of sarcoidosis as a concomitant or associated disorder.