Four cases of well differentiated lymphocytic lymphoma with or without plasmacytoid differentiation of the lung are described. Two cases were single and the others were multiple. Histologic pictures of the lesion showed mass with perivascular, interstitial and alveolar extension in three cases and only interstitial and perivascular involvement in one. Histologically three cases were lymphoplasmacytic lymphoma and one was small lymphocytic lymphoma. Dutcher bodies, granulomas and germinal centers were also found in tumors. Immunohistochemical study revealed monoclonal lymphocytic proliferation in all cases in fresh frozen sections and in three in paraffin sections. Treatment is surgical resection. Chemotherapy is used for residual disease after surgery.