A 73 year old woman has lymphadenopathy and splenomegaly. She feels well but has had recurrent chest infections recently. Choose the single most likely blood film findings?

The key is B. Excess of mature lymphocytes. [Diagnosis is CLL. Chronic lymphocytic leukemia is a type of cancer in which the bone marrow makes too many lymphocytes which looks mature but with defective function. Age of patient is usually above 50 yrs. There is lymhadenopathy and splenomegaly. Repeated chest infection points towards abnormal function of lymphocytes against infection. This is a blood and bone marrow disease that usually gets worse slowly. Therefore survival rates for chronic lymphocytic leukemia are good compared to many other cancers].