Title : A fatal diagnostic pitfall: Disseminated TB presenting as malignancy in a healthcare worker

Abstract:

Introduction:
Disseminated tuberculosis (TB) is uncommon in developed countries but can mimic metastatic malignancy, particularly in immunosuppressed individuals. Early diagnosis is essential to prevent irreversible complications.

Case Description:
A 64-year-old male healthcare worker with a history of polymyalgia rheumatica (on prior infliximab), colon cancer status post-resection (2010), and hypertension presented with three weeks of fevers and weight loss. Imaging showed intra-abdominal lymphadenopathy, terminal ileum thickening, and a spiculated left lung nodule which suggests metastatic cancer. PET scan supported concern for malignancy. He was referred for colonoscopy but presented to the ED with fever (38.6°C) and tachycardia. Initial workup including blood cultures, urinalysis, and respiratory viral panel was negative.

He underwent colonoscopy and endobronchial ultrasound (EBUS), both of which revealed acidfast bacilli (AFB), confirmed by PCR. Disseminated TB was diagnosed. Anti-TB therapy was started but modified due to hepatotoxicity. His hospital course rapidly deteriorated:
supraventricular tachycardia, hypotension, respiratory failure, and cardiac arrest requiring intubation, chest tube, and continuous renal replacement therapy.
Despite full supportive care, he developed persistent encephalopathy. Brain MRI showed global ischemic injury. The patient never regained neurologic function. After family discussions, lifesustaining interventions were withdrawn, and he was transitioned to inpatient hospice.

Discussion:
This case underscores the diagnostic complexity of TB in immunocompromised individuals, especially when presenting like malignancy. Immunosuppression likely facilitated TB reactivation. Biopsy and molecular diagnostics were key to diagnosis. Early suspicion of TB in atypical presentations is crucial to avoid fatal delays.