Intraosseous pseudotumour in a child with mild hemophilia B: report of a rare case and brief review of literature.

Hemophilic pseudotumor is a rare, but well-known, complication of hemophilia occurring in 1-2 % of individuals with a severe factor VIII or IX deficiency. The hemophilic pseudotumor is defined as an encapsulated hematoma that increases of volume progressively by episodes of recurrent hemorrhage; usually originate in soft tissues or in subperiosteal or intraosseous areas. Very seldom, patient with mild form of hemophilia present with intraosseous pseudotumor. This report describe an 11-year-old boy with mild factor IX deficiency (17 % of normal factor IX activity), who developed a pseudotumor of the femur.