Primary lymphoma of lung.

Five cases of primary lymphocytic lymphoma of the lung are described. One patient died 14 years after diagnosis, with spread of the tumour to the opposite lung. The remaining four patients were alive and well 18 months to 25 years after diagnosis. The pathological features of these five cases are described and the nature, diagnosis, therapy, and prognosis are considered in relation to experience in the literature. The tumor is rare. It is important because of its good prognosis and diagnostic difficulty.