Romiplostim therapy induces megakaryocyte hyperplasia similar in morphology to a myeloproliferative neoplasm

Abstract

The thrombopoietin analogue romiplostim was recently approved as a therapy for chronic immune thrombocytopenic purpura. It has showed good efficacy in stimulating a transient or sustained increase in platelet count in a majority of patients. Romiplostim's effect on bone marrow morphology has not been fully described, and we report on two patients on romiplostim therapy who underwent bone marrow biopsies. In both marrows, increased numbers of megakaryocytes with hyperplastic morphology, similar to that seen in myeloproliferative neoplasms, were identified. This morphologic finding could create a diagnostic dilemma or pitfall without appropriate clinical information.