Lung cancer is the leading cause of cancer-associated mortality, with a 5-year survival of 19% for all types of lung cancer. Lymphoidmalignancies of the lung have a significantly better prognosis, with 5-year survival approaching 90%, making it very important to identifythese patients. As the signs and symptoms, laboratory investigations, and radiological features are non-specific and vague and the histological confirmation is invasive, they are usually either not diagnosed or diagnosed very late. We present a case of an elderly male whowas treated for months with antituberculosis treatment (ATT) before being properly evaluated and diagnosed with primary pulmonarymarginal cell lymphoma. This case was unique for having gross pleural effusion as a presenting feature and having been diagnosed withthe help of radial endobronchial ultrasound (EBUS).