A rapidly progressive case of tuberculous pleurisy and pericarditis in a patient with non-small cell lung cancer that developed one month after receiving pembrolizumab monotherapy.

We report a rapidly progressive case of tuberculous pleurisy and pericarditis. A 59-year-old, male patient with non-small-cell lung cancer commenced pembrolizumab monotherapy one month before but soon thereafter had fevers and dyspnea. Radiography revealed increased right pleural effusion, novel left pleural effusion and cardiomegaly, which had been absent 10 days earlier when a reduction in the target lesion was confirmed. Computed tomography revealed the presence of pericardial fluid. Analysis of the pleural effusion didn't detect malignancy; however, the culture was positive for tuberculosis. It suggests that pembrolizumab may have induced severe inflammation leading to the rapid progression of the disease.