<prompt> All of the following statements about Hairy cell leukaemia are true except:Splenomegaly is conspicuousResults from an expansion of neoplastic T lymphocytesCells are positive for Tarate Resistant Acid phosphataseThe cells express CD25 consistently  <response>: Answer is B Results from an expansion of Neoplastic T lymphocytes Hairy cell leukemia ica B cell neoplasm and is characterked by expansion of neoplasticB cells not T lymphocytes Hairy cell leukemia: Hairy cell leukemia is a rare but distinctive form of chronic B cell leukemia that derives its name from the appearance of fine hair like projectionsdeg on the leukaemic cells large B cells Characteristic cytochemical feature: Presence of tarate resistant acid phosphatase TRAP 0 in neoplastic B cells Cellular features Markers Hairy cells express the pan B cell markers CD 19 and CD 20 and monocyte associated antigen CD 11 Plasma cell associated antigen PCA-1 is also present - Robbins Expression of CD 25, IL2 and specific adhesion molecules - Harrison 14th695 Clinical features Present predominantly in the older age group 40 yearsdeg result largely from infiltration of bone Massive splenomegalydeg hepatomegaly is less common marrow liver and spleen Lymphadenopathy PancytopeniaQ Recurrent infections Treatment Q Current treatment of choice is with purine analogues - Cladribinedeg Other drugs used - Pentostotindeg - Interferon c0 Splenectomy used to be the standard treatment earlier 