Effects of extensive splenomegaly in patients with myelofibrosis undergoing a reduced intensity allogeneic stem cell transplantation.

Changes in spleen size postallogeneic haematopoietic stem cell transplantation (HSCT) in patients with primary myelofibrosis have been poorly characterized. We analysed 10 patients with myelofibrosis and splenomegaly following a reduced-intensity allogeneic HSCT. All patients fully engrafted donor cells including five patients with extensive splenomegaly. Extensive splenomegaly was associated with a prolonged time to neutrophil and platelet recovery. In all 10 patients, a progressive reduction of splenomegaly was documented within 12 months post-transplant and paralleled the reduction of marrow fibrosis. These findings suggest that myelofibrosis patients with extensive splenomegaly may proceed with allogeneic HSCT without prior splenectomy.