Chronic neutrophilic leukemia (CNL) is a rare BCR-ABL1-negative myeloid malignancy that is characterized by mature granulocytosis without dysgranulopoiesis.
JAK2V617F mutation screening is indicated for the evaluation of erythrocytosis, thrombocytosis, splanchnic vein thrombosis, and otherwise unexplained BCR-ABL1-negative granulocytosis.