Hemophilic pseudotumor is a rare complication of hemophilia occurring
in 1 % to 2 % of individuals with a severe factor VIII or IX deficienc
y. This pseudotumor has been defined as a progressive cystic swelling
involving muscle that is produced by recurrent hemorrhage and may be a
ccompanied by roentgenographic evidence of bone involvement. The case
is presented of a 12-month-old child with mild factor VIII deficiency
(10% of normal factor VIII activity), who developed a pseudotumor of t
he skull.