The Risk of Misdiagnosing the Primary Site Responsible for Bone Metastases in Patients With Chronic Lymphocytic Leukemia and a Second Primary Carcinoma.

Chronic lymphocytic leukemia (CLL) is a common malignancy which may coexist with other primary cancers. CLL is rarely the cause of solitary bone lesions; such lesions in the context of CLL are believed to result from either Richter's transformation or metastasis from another primary malignancy. Renal cell carcinoma (RCC), on the other hand, is a malignancy which frequently metastasizes to bone and may cause an osteolytic solitary bone lesion.