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

Abstract

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.

Hepatic, Splenic, and Gastrointestinal Involvement with Sarcoidosis

“…[121][122][123] The differential diagnosis of small-intestinal granulomas includes tuberculosis, leprosy, Whipple's disease, fungal infection, lymphoma, and Crohn's disease. 123,124 The main difficulty in establishing the diagnosis is differentiation from Crohn's disease, which may also display granulomas on small bowel biopsy. The presence of granulomas outside of the gastrointestinal tract strongly supports the diagnosis of sarcoidosis.…”

PCR analysis in the pathological diagnosis of Whipple's disease: emphasis on extraintestinal involvement or atypical morphological features

“…Vacuolated macrophages are found in the vast majority of such cases, but the existence of atypical features such as non-caseating sarcoid granulomas may be misleading. [9][10][11][12] This is particularly important when the patient does not suffer from the typical clinical symptoms of the disease, or when extraintestinal manifestations occur in the absence of a histologically established involvement of the small bowel. With the method described, we have shown that PCR analysis of the specific DNA from extraintestinal sites may lead to the correct diagnosis.…”

“…Such a granulomatous reaction, regarded as an early manifestation of the disease, may lead to the incorrect diagnosis of sarcoidosis. [9][10][11][12] The detection of the specific bacterial ribosomal RNA (rRNA) gene of Tropheryma whippelii by polymerase chain reaction (PCR) can be used to confirm the diagnosis of WD. [13][14][15][16][17] In this article, we have assessed the value of PCR analysis in the pathological diagnosis of WD in a number of intestinal and extraintestinal surgical pathology specimens.…”

Chronic interstitial nephritis in Whipple's disease

“…On the basis of 20,000 autopsies performed at the Institute of Pathology of Basel, we calculated that this chance association may happen once in 108 autopsies. Therefore, we interpret the granulomas as a result of an immunologic reaction to bacterial degradation products in Whipple's disease [12,14,17]. The immunofluorescent findings do not indicate that streptococci are the causative agent because by electron microscopy it was bacilli and not cocci that were found.…”

“…We were unable to demonstrate SPC cells either with special stains or by immunofluorescence of streptococcal antigens within the granulomas. Granulomas in Whipple's disease were interpreted either as the result of a chance coincidence with sarcoidosis [13] or as a reaction to degradation products of the bacteria in Whipple's disease [12,14,15]. The latter interpretation is favored by the presence of SPC cells partly within and partly in the surroundings of granulomas [14].…”