Non-Hodgkin's lymphomas of the lung. A study of 19 cases emphasizing the utility of frozen section immunologic studies in differential diagnosis.

Nineteen cases of possible non-Hodgkin's lymphoma of the lung were studied by conventional morphologic methods and by immunohistochemical methods employing monoclonal antibodies applied to frozen tissue sections. In five of the 19 cases, the original histologic diagnoses were revised after review of the immunologic findings. Problem areas clarified by immunodiagnosis included the differential diagnoses of pseudolymphoma versus small lymphocytic lymphoma (two cases), Hodgkin's disease versus non-Hodgkin's lymphoma (two cases) and non-Hodgkin's lymphoma versus lymphomatoid granulomatosis (one case). Of the seven lymphomas presenting exclusively in the lung without a prior history of lymphoma, three were small lymphocytic, one was diffuse mixed small cleaved and large cell, and three were diffuse large-cell lymphomas. Four of these lymphomas typed as B-cell, two typed as T-cell, and one was of undefined phenotype.