The most common physical finding in a patient with hairy cell leukemia (HCL) is:
A. Massive splenomegalyHairy cell leukemia (HCL) is an uncommon blood disorder, representing only 2% of all adult leukemias. HCL is characterized by splenomegaly, pancytopenia, and large numbers of abnormal lymphocytes in the bone marrow. These lymphocytes contain irregular hair-like cytoplasmic projections identifiable on the peripheral smear. Most patients seek medical attention because of symptoms related to anemia, neutropenia, thrombocytopenia, or splenomegaly. The most common physical finding is splenomegaly, which occurs in 80% of patients with HCL and the spleen is often palpable 5 em below the costal margin. Many patients with HCL have few symptoms and require no specific therapy. Treatment is indicated for those with moderate to severe symptoms related to cytopenias, such as repeated infections or bleeding episodes, or to splenomegaly, such as pain or early satiety. Splenectomy does not correct the underlying disorder, but does return cell counts to normal in 40 to 70% of patients and alleviates pain and early satiety. Newer chemotherapeutic agents (the purine analogues 2' -deoxycoformycin [2' -DCF] and 2-chlorodeoxyadenosine [2-CdA] ) are able to induce durable complete remission in most patients.