<prompt> All of the following NHL involve the white pulp of spleen ExceptHairy cell leukemiaBurkitt lymphomaFollicular lymphomaMantle cell lymphoma  <response>: Hairy cell leukemia is a rare, slow-growing cancer of the blood in which your bone marrow makes too many B cells lymphocytes, a type of white blood cell that fights infection. These excess B cells are abnormal and look hairy under a microscope. 