Pathology of intestinal tuberculosis and its distinction from Crohn's disease.

Intestinal lesions of 212 cases presenting with symptoms of intestinal obstruction were studied. Of these, 159 cases were diagnosed as tuberculosis and 10 as Crohn's disease. Forty-three cases could not be classified into any of these entities and are excluded from this account. The amount of chemotherapeutic drugs received by each patient preoperatively was recorded. Cases proved as tuberculosis at the first operation were put on antituberculosis chemotherapy. Thirteen of these cases were operated on a second time, and tissue reactions under the influence of chemotherapy were studied. Fresh diseased tissue was studied for acid-fast organisms by culture and animal inoculation.Morphological features of the tuberculosis group are described in detail. Although the cases were broadly classified into the ulcerative and ulcerohypertrophic varieties, a distinction was not always sharp and the two types of lesions were at times found to coexist. The macroscopic features presented a very wide range, and at times distinction from Crohn's disease, especially in the ulcerohypertrophic variety, was difficult. Microscopically, however, they could be distinguished without much difficulty. Caseation, although a characteristic feature of tuberculous granulomas may, albeit rarely, be absent. Granulomas which are characteristically confluent may be present only in the mesenteric lymph nodes. Acid-fast organisms are not grown consistently from diseased tissues; where grown, they are of human type. Reparative changes during chemotherapy are described in detail; these follow a non-specific pattern. In the group of Crohn's disease, transmural cracks and fissures were consistently observed in all cases. Distinguishing features between the two diseases are discussed in detail.