Solitary extramedullary plasmacytomas are plasma cell tumors that tend to develop in mucosa-associated lymphoid tissues including the sinonasal or nasopharyngeal regions. Primary plasmacytoma of the lung is exceedingly rare and often presents as a solitary mass or nodule in mid-lung or hilar areas and diagnosed after resection. Herein, we report a case of primary pulmonary plasmacytoma that presented with diffuse alveolar consolidation and diagnosed by transbronchial lung biopsy.