A 46-year-old man with factor VIII deficiency presented with a rare case of 
hemophilic pseudotumor in the temporal bone manifesting as severe conductive 
hearing loss and external ear bleeding. The pseudotumor expanded and destroyed 
the temporal bone and skin of the external ear over the course of 8 years. The 
pseudotumor was surgically excised, and the patient's symptoms improved. 
Histological examination of a specimen collected from inside the pseudotumor 
demonstrated blood products in various stages of evolution and showed that the 
outer membrane consisted of a collagen layer. Hemophilic pseudotumors are rare 
complications occurring in 1-2% of patients with mild or severe hemophilia. 
Pseudotumors are chronic, slowly expanding, encapsulated cystic masses, and most 
are located in the long bones and pelvis. The present case suggests that cranial 
pseudotumor should be considered in the differential diagnosis of cranial lesion 
in a patient with hemophilia.