Reactivation of pulmonary tuberculosis mimicking disease progression during immune checkpoint inhibitor therapy

A man in his late 60s, with no comorbidities, with a prior smoking and alcohol intake history, was evaluated for a swelling in the left upper neck. Histopathology and PET-CT (positron emission CT) were suggestive of a poorly differentiated squamous cell carcinoma of the left pyriform fossa, cT2N2(p16-) with bilateral pulmonary nodules and mediastinal lymphadenopathy ( figure 1A,D). A biopsy of the pulmonary nodule showed tuberculosis (TB). He received radical chemoradiation with weekly carboplatin and nimotuzumab and completed the course of antitubercular therapy (ATT) (2-month intensive phase (IP) ATT with isoniazid, rifampicin, pyrazinamide and ethambutol, followed by 4-month continuation phase isoniazid, rifampicin and ethambutol) for 6 months. After 3 months, the review PET-CT showed a complete radiological response. On follow-up, he developed a nodal recurrence at 1 year (figure 1B), confirmed by histopathology.