From primary myelofibrosis to chronic myeloid leukemia, BCR::ABL1+ B-Lymphoblastic leukemia, and back to primary myelofibrosis: An illustration of dynamic clonal evolution.

The simultaneous detection of BCR::ABL1 and JAK2 V617F was rarely reported and their clonal relationship and dynamic clonal shift were not characterized. Here, we described a unique case with the initial presentation as JAK2 V617F+ primary myelofibrosis, followed by the emergence of BCR::ABL1+ chronic myeloid leukemia. The patient then developed BCR::ABL1+ B-lymphoblastic leukemia. Treatment for B-lymphoblastic leukemia prompted a regression to the state of primary myelofibrosis. In light of these observations, we proposed a clonal evolution model for this case.