Disseminated Tuberculosis Presenting With a Nodo-Colonic Fistula in a Newly Diagnosed HIV-Positive Patient: A Case Report From Tanzania

We present the case of a 35-year-old male with no known comorbidities who presented with chronic gastrointestinal (GI) and constitutional symptoms and was empirically treated with several antibiotics during multiple clinic visits at different health facilities. The laboratory test sent included a stool GeneXpert, which was positive for Mycobacterium tuberculosis (MTB). CT imaging revealed multiple necrotic abdominal and retroperitoneal lymph nodes, hypoenhancing splenic lesions, a nodo-colonic fistula between the necrotic retroperitoneal lymph nodes and the adjacent colon, and a mild left-sided pleural effusion. Colonoscopy demonstrated caseating discharge from the fistulous tract 40 cm from the anal verge, and histology showed abundant neutrophils and histiocytes with areas of caseous-like necrosis. The patient was diagnosed with disseminated tuberculosis (TB) with newly diagnosed HIV stage 4. Antituberculous therapy was initiated, followed by antiretroviral therapy (ART) two weeks later in accordance with World Health Organization and national treatment guidelines. This case highlights the need for a thorough evaluation of a patient with a history of chronic GI symptoms and the importance of maintaining a high index of suspicion when diagnosing disseminated TB. In TB-endemic regions, a differential diagnosis of TB should be sought in patients presenting with GI and constitutional symptoms, and such symptoms should prompt an HIV test. Imaging plays a pivotal role in identifying key features such as lymphadenopathy and fistulous tracts, and colonoscopy can show a caseating discharge, which should raise suspicion for chronic infectious or granulomatous diseases, including TB. Although rare, nodo-colonic fistula formation can occur as a complication of abdominal TB. Conservative management can be effective in stable patients, potentially avoiding the morbidity of surgical intervention, as demonstrated in this case. Comprehensive management, including prompt initiation of anti-TB therapy, timely ART, prophylaxis for opportunistic infections, and nutritional support, is crucial to optimize outcomes in such complex presentations.