Unusual intradiploic hematoma.

This 58-year-old man presented with a left frontal bone lesion that had been growing over a 2-year period. The lesion increased in size, resulting in proptosis that affected the patient's visual acuity and eyeball movement. On computerized tomography and x-ray studies, a huge lesion located between the widened frontal diploic bone and involving the orbital roof and paranasal sinuses was noted. The entire lesion was radically resected. The authors unexpectedly found that an intradiploic organized hematoma had caused the swelling.