Abstract
Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL). DLBCL presents with pleural involvement at an advanced stage; however, primary pleural lymphomas without any other site of involvement are rare, and the possibility of misdiagnosis is high, particularly in developing countries, where tuberculosis or other severe pulmonary infections remain a major health concern. Furthermore, lymphoma and tuberculosis share a number of common clinical characteristics, such as fever, night sweats, feeling of satiety after a small meal, fatigue and unexplained weight loss, among others. We herein describe a case of misdiagnosis of primary pleural lymphoma as tuberculosis in a 49-year-old male patient who presented with pleural effusion and high adenosine deaminase (ADA) level in the pleural fluid. Anti-tuberculosis treatment was administered for 1 month, but the patient's condition deteriorated. A surgical biopsy was performed and was diagnostic of DLBCL. CHOP chemotherapy was administered with a significant delay due to the misdiagnosis, and it was not efficient, as rituximab was not added to the regimen. The therapeutic efficacy was monitored by computed tomography scans, which revealed that the lesion had shrunk slightly. The overall survival of the patient was ~1 year and he eventually succumbed to severe thoracic infection and pleural effusion. Suspicion should be raised when a patient presents with pleural effusion and extremely high ADA levels, as ADA activity of >250 U/L should raise the suspicion of empyema or lymphoma rather than tuberculosis.