S3570 Imposter Posing a Difficult Difficulty: The Great Masquerader of Pancreatic Tuberculosis

Introduction: Pancreatic Tuberculosis is a rare clinical entity. It represents a diagnostic challenge as it can be easily confused with malignancy or pancreatitis on imaging. This could result in unnecessary surgery. As this is a treatable disease it is imperative to diagnose this condition pre-operatively. Case Description/Methods: A 50-year-old man with hypertension and hypothyroidism, recently diagnosed with AML, presented with a 1-month history of high-grade fever. There were no gastrointestinal symptoms, weight loss, or night sweats. Examination was notable only for fever (38.7°C). Labs revealed pancytopenia: hemoglobin 8.4 g/dL, WBC 1.2 × 10⁹/L, platelets 42 × 10⁹/L, and ANC 200/µL. Febrile neutropenia was confirmed, and empiric broad-spectrum antibiotics were started. Due to persistent fever, further workup was performed. Serum and BAL galactomannan were positive, suggesting invasive aspergillosis; liposomal amphotericin B was initiated. Abdominal ultrasound revealed a bulky pancreas with heterogeneous echotexture. Computed tomography showed a 2 × 3 cm heterogeneously enhancing lesion in the pancreatic tail. CA 19-9 was normal. Endoscopic ultrasound (EUS) demonstrated a hypoechoic pancreatic lesion. Differentials included leukemic infiltration, pancreatic malignancy, invasive fungal infection, and pancreatic tuberculosis. FNAC revealed granulomatous inflammation with caseous necrosis. GeneXpert MTB/RIF was positive for Mycobacterium tuberculosis. ATT was initiated, and fever resolved within 10 days. Follow-up imaging at 3 months showed complete resolution. He completed 6 months of ATT uneventfully. The presence of a pancreatic mass without GI symptoms complicated diagnosis. EUS-FNAC with GeneXpert was key to confirming TB and avoiding unnecessary surgery. Discussion: Pancreatic tuberculosis (TB) is a rare form of extrapulmonary TB, comprising <5% of abdominal cases. It often affects younger or immunocompromised individuals, including those with HIV or malignancy. Symptoms are non-specific—fever, abdominal pain, weight loss, and night sweats. Jaundice may occur with biliary involvement. Imaging often mimics pancreatic cancer or pancreatitis, showing solid or cystic lesions. EUS with fine needle aspiration enables high-resolution imaging and tissue sampling. Cytology may reveal granulomas, but definitive diagnosis requires AFB detection, culture, or PCR (e.g., GeneXpert). Early diagnosis and ATT can lead to full recovery and avoid unnecessary surgery.