[Hairy cell leukemia revealed by an isolated neutropenia]

Hairy cell leukemia is a rare lymphoproliferative disorder which affect predominantly older males. Typical presentation includes pancytopenia, splenomegaly, presence of malignant cells with hairy projections, and some difficulty to perform a bone marrow aspiration. Reported is a 78 year - old female patient, who presented only neutropenia. There was no splenomegaly and the bone marrow aspiration was easy. Diagnosis was based on the presence of characteristic cells in a second bone marrow aspiration, whereas a treatment by recombinant human G-CSF was introduced for a suspicion of an idiopathic neutropenia. Confirmation was done with immunostaining by DBA 44 monoclonal antibody. This is the first case of hairy cell leukemia reported in Dakar, and with an uncommon clinical presentation making it difficult to be recognized.