Myelofibrosis successfully treated with prednisolone in a patient with pachydermoperiostosis.

Pachydermoperiostosis (PDP) is a rare disorder of bone and connective tissue growth. A 21-year-old man was referred to our hospital with anemia. He showed characteristics of PDP. Bone marrow biopsy showed myelofibrosis. Chromosomal abnormalities or JAK2 mutation were not found. Anemia gradually progressed, and he became transfusion-dependent. Oral prednisolone was initiated; it gradually improved his anemia and rendered the patient free of transfusion. However, other clinical symptoms such as clubbed fingers and skin hypertrophy remained unimproved. In this case, the serum concentration of vascular endothelial growth factor and transforming growth factor-β levels were increased. Further investigation will be necessary to establish appropriate treatment strategies for this disease.