We report two cases of solitary plasmacytoma of the lung. Computed tomographic scan disclosed in case A a solid tissue formation in a cystic pulmonary lesion and in case B a solitary nodule. Suggesting aspergilloma in A and pulmonary malignancy in B diagnostic thoracotomies were performed and the respective findings were resected. In both cases a diagnosis of plasmacytoma was made. Postoperatively multiple myeloma was ruled out. Solitary pulmonary plasmacytoma is a very rare condition and to the best of our knowledge plasmacytoma within a cystic lung lesion has not been described so far. After curative resection treatment the prognosis of these circumscript lesions should be excellent.