[Novelties in the diagnostics and therapy of hairy cell leukemia]

Differential diagnosis of hairy cell leukemia (HCL) and related disorders (hairy cell leukemia variant and splenic marginal zone lymphoma) is of utmost importance since the treatment and prognosis of these lymphomas differ. Since 2011 diagnosis of hairy cell leukemia has been easier because of discovery of the disease defining somatic mutation BRAF V600E mutation, which has been also known as driver mutation in malignant melanoma. The presence of this mutation enabled targeted molecular therapy in HCL as well. As first line therapy purine nucleoside analogues are the gold standard, but refractory/relapsed patient are candidates for targeted BRAF-inhibitor therapy. This manuscript serves as guidance in making diagnosis and standard treatment of HCL, and summarizes newest data about molecular therapy, including our single center experience collected from 75 patients.