Coexistence of Prefibrotic Myelofibrosis with Monoclonal Gammopathy of Undetermined Significance: A Case Report.

The coexistence of dual hematological neoplasms is an unusual and challenging presentation due to the different combination of etiopathology. The presentation of synchronous dual hematological malignancies can be one of the 3 types: myeloid + lymphoid or dual lymphoid or dual myeloid. Here, we are reporting a case of a 53-year-old male with simultaneous presence of JAK2 V617F-positive myeloproliferative neoplasm with features favoring prefibrotic phase of primary myelofibrosis (pre-PMF) in combination with monoclonal gammopathy of undetermined significance (MGUS). In such cases of simultaneous existence of dual hematological neoplasm management, it is recommended to treat the more aggressive one. Currently, our management plan is focusing on treating the pre-PMF and observation of MGUS with regular monitoring for transformation to MM.