Overcoming Anchoring Bias: Granulomatosis With Polyangiitis in a Patient From a Tuberculosis-Endemic Region

The differential diagnosis of a patient presenting with constitutional symptoms and pulmonary cavitary lesions on chest X-ray is broad, including pulmonary tuberculosis (TB) and vasculitic lung disease. Clinicians may consider sociodemographic factors in sequencing their differential, which should be verified with diagnostic tests according to appropriate pretest probability. Here, we present a case of misdiagnosing granulomatosis with polyangiitis as pulmonary TB. Although native to an endemic country, this patient had multiple negative TB tests and did not respond to rifampin, isoniazid, pyrazinamide, and ethambutol therapy. We consider anchoring implicit bias as a contributing factor for this patient's misdiagnosis and make recommendations for clinicians.