Case report. The authors present a rare case of ossified chronic epidural hematoma. A 13-year-old female patient presented with an ossified chronic epidural hematoma. She had sustained a head injury about 10 weeks previously and had received conservative care for a delayed-onset epidural hematoma at a local hospital. Ossification was identified about 4 weeks after the head injury and then progressed rapidly. A chronic epidural hematoma with a thick collagenous capsule and newly formed bone was removed 73 days after the head injury.
Conclusion. An epidural hematoma with mild symptoms can be treated conservatively. When, however, the hematoma is observed not to be naturally absorbed during serial follow-up examinations, surgical removal must be considered, even if the patient's condition is good, because this entity carries the risk of bone calcification and ossification.