Syngeneic stem cell transplant for spent-phase polycythaemia vera: eradication of myelofibrosis and restoration of normal haematopoiesis.

We report a patient with spent-phase polycythaemia vera (S-PV) and massive splenomegaly who failed to engraft after a syngeneic granulocyte colony-stimulating factor-primed peripheral blood stem cell transplant (SCT), but later engrafted after splenectomy. Bone marrow (BM) showed resolution of myelofibrosis (MF) and absent endogenous erythroid colonies. This case demonstrated that (1) normal haematopoiesis can be restored after syngeneic SCT despite extensive MF, and (2) fibrosis can regress following a total body irradiation-containing regimen and syngeneic SCT. As a graft-versus-BM stroma effect is non-existent in syngeneic transplants, there may be a role for autologous SCT to obliterate MF in S-PV.