Chronic lymphocytic leukemia (CLL) can be characterized by the accumulation of small mature lymphocytes in the peripheral blood, bone marrow and other lymphoid tissues. It is well known that the risk of secondary malignancy is high in patients with CLL. A secondary malignancy in a patient with CLL may influence the prognosis as well as the treatment of CLL. As CLL is a rare disease in Korea, there have been only a few reported Korean cases of CLL with secondary malignancy. We experienced the case of a 73-year-old man who suffered from CLL with basal cell carcinoma of the skin and non-small cell lung cancer. At first, he presented with excessive lymphocytosis (＞100,000/mm³), anemia, thrombocytopenia and splenomegaly, and he was diagnosed with CLL according to the bone marrow biopsy. Simultaneously he had basal cell carcinoma on his face. Seven months later, he began to feel chest discomfort and his chest X-ray showed a mass like lesion on the left upper lung. It was proven to be non-small cell lung cancer by bronchoscopic biopsy. (Korean J Hematol 2009;44:133-138.)

Keywords: Chronic lymphocytic leukemia, Basal cell carcinoma, Lung cancer