[Aneurysmal bone cyst of the skull -a case report- (author's transl)].

Aneurysmal bone cyst of the skull is rarely seen. There are 29 reported cases in the literatures as far as we could collect. We reported an additional case of aneurysmal bone cyst of the skull which originated from the right parietal bone of 4-year-old boy. We have summarized these 29 cases. The age incidence in this series is from 14 month-old to 31 year-old. There are 11 cases under the age of 10. In most cases clinical symptoms are palpable mass or headache and exophthalmos. Eyeball displacement and proptosis are also the symptoms when this disease occurs at the orbital roof. According to the characteristic radiographic appearance, it is "blown-out pattern with a shell of periosteal new bone over the mass or soap-bubble appearance". However in our case the radiological finding was osteolytic. It is possible to remove totally when this lesion occurs in the cranial vault, but only curettage may be performed when the skull base is involved. Total removal is the best treatment. Radiation therapy is usually done in the recurrent cases. It is necessary to follow up for at least 4 years because of the rarity of recurrence beyond 4 years after the initial treatment. We also described the other differential diseases and pathogenesis of this disease.