Extramedullary Hematopoiesis in Myelodysplastic Syndromes: A Systematic Literature Review

Abstract

Extramedullary hematopoiesis is rarely seen in patients with myelodysplastic syndromes, and its clinical characterizations are not well-defined. Here, we systematically reviewed the published literature to summarize the clinical manifestations, treatments, and long-term outcomes of biopsy-proven extramedullary hematopoiesis in patients with myelodysplastic syndromes. We included 41 patients, and ring sideroblasts were the most common myelodysplastic subtype (30.6%). Extramedullary hematopoiesis was typically symptomatic on presentation due to local compression, frequently involving the liver or spleen (36.6%), or the paravertebral region (24.4%). Notably, ring sideroblasts were predominantly seen in patients with non-hepatosplenic involvement (38.5 vs. 6.7%, p = 0.034). Interventions, when required, usually included surgery (36.8%) or radiation (13.2%), which led to symptomatic improvement in 55.5% of patients. The median overall survival of the current cohort was 7 months. The current study confirms the rarity of extramedullary hematopoiesis as a complication of myelodysplastic syndromes; however, its outcomes in response to systemic modern therapies require further investigation.