Isolated biliary tuberculosis: a rare case report and diagnostic challenges

Introduction and importance Biliary tuberculosis is a rare form of Mycobacterium tuberculosis infection, accounting for only 0.0-0.1% of all TB cases in certain settings. Its preoperative diagnosis is difficult due to nonspecific symptoms and the lack of specific imaging criteria. Often, it mimics other diseases like cancers and infections, complicating early detection. Case presentation A 51-year-old female with a past medical history of diabetes mellitus, hypothyroidism, and a biliary stricture following stent placement presented with nausea, vomiting, loss of appetite, and weight loss for 4 months. A CT scan revealed an indwelling common bile duct (CBD) stent, mild intrahepatic biliary ductal dilatation, and pneumobilia. An endoscopic retrograde cholangiopancreatography (ERCP) procedure was performed with stent exchange. Initial CBD biopsy showed chronic inflammation, but both biopsy and fine-needle aspiration (FNA) were negative for malignancy. A subsequent ERCP with additional biopsies also returned negative results for malignancy, though CBD brushing tested positive for M. tuberculosis . Clinical discussion The diagnosis of biliary tuberculosis is challenging due to its nonspecific presentation. In this case, the positive result for M. tuberculosis in the CBD brushing led to the diagnosis, even after negative biopsy and FNA results. Early recognition of hepatobiliary tuberculosis is crucial as it enables conservative management with stents and anti-tuberculosis therapy (ATT). Conclusion Biliary tuberculosis, although rare, should be considered in patients with unexplained biliary symptoms. Timely diagnosis through appropriate diagnostic procedures can lead to effective treatment with ATT and stenting, improving patient outcomes, and preventing more invasive treatments.