Background: Hemophilic pseudotumor is an unusual complication occurring in only 1% to 2% of patients with severe factor VIII or IX deficiency, and manifests as a progressive enlargement of hematoma by recurrent hemorrhage, often resulting in bone destruction or resorption due to the chronic pressure of osseous hemorrhage. Cranial hemophilic pseudotumors are extremely rare, with only 4 previous cases associated with mild or moderate factor XIII deficiency.
Case description: A 24-year-old man with moderate deficiency of factor IX developed a cranial pseudotumor as a swelling in the frontal scalp. Blood coagulation profile revealed extended activated partial thromboplastin time (58.2 seconds). Factor IX analysis showed 3% of normal activity. Computed tomography and magnetic resonance imaging demonstrated an extra-axial lesion with bone destruction, enhanced rim, and signal changes consistent with chronic hemorrhage. Surgical removal was performed. Histologic examination disclosed old blood coagulum.
Conclusions: This case of cranial hemophilic pseudotumor in a patient with moderate factor IX deficiency suggests that cranial pseudotumor should be considered in the differential diagnosis of cranial lesion in a patient with hemophilia, and adequate replacement therapy in the perioperative period is essential to achieve safe surgical removal.