Brainstem Tuberculous Abscess in a 63‐Year‐Old Adult With Unrepaired Tetralogy of Fallot

Background Tetralogy of Fallot (TOF) is a congenital heart anomaly usually corrected surgically in childhood. Reports of adults with unrepaired TOF indicate that they are at high risk of endocardial infections and sequelae such as distant abscesses. Case Presentation A 63‐year‐old man born and raised in Vietnam presented with unrepaired TOF and 5 days of dizziness, dysarthria, and left‐sided weakness. Magnetic resonance imaging (MRI) of the brain demonstrated a 2.9‐cm rim‐enhancing pontine lesion with associated edema and a punctate acute infarct in the right cerebellum. Echocardiogram of the heart revealed right‐to‐left shunting, while chest computerized tomography (CT) showed a left apical cavitary mass. Initial studies were negative for bacteremia and endocarditis. Due to clinical suspicion and a positive QuantiFERON Gold tuberculosis (TB) test, antituberculous therapy was initiated. Biopsy of the central nervous system (CNS) lesion was deferred due to risk, and therapy was continued with antituberculous agents and steroids. The patient improved with a final diagnosis of tuberculous brainstem abscess. Conclusion This case highlights early recognition and awareness of potential complications associated with untreated TOF as well as suspicion for TB in the proper clinical setting. Complex cases involving rare diagnoses should be approached systematically, evaluating possible diagnoses in order of urgency and basing invasive procedures on patient risk–benefit.