Co-occurrence of JAK2 V617F-mutated essential thrombocythemia and chronic lymphocytic leukemia harboring der(8;17)(q10;q10).

BACKGROUND AND CASE: We herein present a case of the co-occurrence of JAK2-mutated essential thrombocythemia (ET) with chronic lymphocytic leukemia (CLL) harboring the recurrent and rare whole-arm translocation, der(8;17)(q10;q10). The co-existence of lymphoproliferative neoplasms and myeloproliferative neoplasms is suggested to be a rare event. Under this condition, the lymphoproliferative disorder presents a clinically indolent course with a low-risk biological profile. However, the present case showed aggressive disease progression, reflecting a poor prognostic factor; that is, the loss of 17p caused by the whole-arm der(8;17)(q10;q10) translocation.

CONCLUSION: The present case report emphasizes the importance of considering the involvement of a genetically poor prognostic factor, regardless of the co-occurrence of CLL and ET.