Extramedullary plasmacytoma originating from the bronchus is a very rare condition, and the radiological diagnostic criteria for this disease are not well established due to its rarity. It often appears as a tumor with smooth margins and very rarely invades the surrounding structures. A computed tomography scan and a positron emission tomography/computed tomography scan were performed on a 71-year-old male patient who was admitted for hemoptysis. A solid mass with irregular margins infiltrating the surrounding vasculature and mediastinum was observed, and a presumptive diagnosis of lung cancer was made. However, bronchoscopy with transbronchial biopsy and immunohistochemical staining confirmed the diagnosis of extramedullary plasmacytoma. We herein present a rare case of extramedullary plasmacytoma which mimiked lung cancer.