Primary myelofibrosis terminated in basophilic leukemia and successful allogeneic bone marrow transplantation.

Transformation of primary myelofibrosis (PMF) to basophilic leukemia is very rare. We report the case of a 44-year-old man who had had PMF for 6 years. His hematopoiesis deteriorated with marked splenomegaly, requiring multiple red blood cell and platelet transfusions. Soon after splenectomy, progressive basophilia (32.3 x 10(9)/L) developed, infiltrating the skin as well as the bone marrow. The patient underwent allogeneic bone marrow transplantation with cells from an HLA-matched sibling. Despite the presence of hyperhistaminemia (99.1 ng/mL) after conditioning with cyclophosphamide, the pregrafting and post-grafting periods were uneventful. Prophylactic administration of both H1 and H2 receptor antagonists and sufficient hydration appeared to be important.