To explore the clinical characteristics, diagnosis, and treatment of chronic lymphocytic leukemia with secondary pancytopenia. Here, a case of pancytopenia secondary to chronic lymphocytic leukemia is reported. Additionally, a review of relevant chronic lymphocytic leukemia literature was conducted to summarize its diagnosis, clinical characteristics, treatment history, and experience. After treatment with cyclosporine A, the patient's chronic lymphocytic leukemia continued to resolve, and hematopoiesis returned to normal. Cyclosporine A therapy resulted in improved patient outcomes. However, the mechanism by which cyclosporine A rebuilds the immune microenvironment and its antileukemia effect in the body remains to be studied. [ABSTRACT FROM AUTHOR]