Tumor Lysis Syndrome after the Administration of Ruxolitinib in a Patient with Post-polycythemia Vera Myelofibrosis.

The development of tumor lysis syndrome (TLS) in association with treatment for myeloproliferative neoplasms (MPNs) is relatively rare. We herein present the case of a post-polycythemia vera (PV) myelofibrosis patient with massive splenomegaly who developed laboratory TLS after treatment with ruxolitinib, a potent JAK1/JAK2 inhibitor. She also exhibited a rapid reduction of spleen volume. Our present case suggests the potential risk of TLS development after ruxolitinib treatment, particularly in patients with massive splenomegaly.