A 65 year old man presents to the clinic complaining of weakness and recurrent infections for 6 months. He has no significant medical, surgical or family history. Physical examination reveals multiple enlarged lymph nodes. Histopathology reveals excessive mature B cells that mark strongly with CD5 and CD23 and weekly with CD22. They also have weak expression of kappa chains on the plasma membrane. What is the most likely diagnosis? A- Acute lymphatic leukemia B- Chronic lymphocytic leukemia C- Chronic myeloid leukemia D- Hairy cell leukemia E- Sezary syndrome Answer
