[Case of aneurysmal bone cyst of the skull].

A case of aneurysmal bone cyst of the right temporal bone was reported. The patient was a 36-year-old male who was admitted to our hospital with complaints of decreased right hearing and transient impairment of the right vision. A large tumor was palpated on the right temporal bone. Neurological examinations revealed right auditory loss, along with right facial weakness of peripheral type, and minimal pyramidal signs on the right side. The results of the laboratory examination proved to be normal. Neuroradiological examinations tended to be quite impressive. Plain x-ray films of the skull showed a blow out appearance of the right temporal bone and a bone decay in the right middle fossa, the right anterior clinoid process, and the posterior half of the right zygomatic arch. Angiograms revealed a right temporal extradural mass lesion without vascularity. CT scans showed a moderately enhanced mass lesion of soap bubble appearance in the right middle fossa. Surgical treatment was done under the diagnosis of extradural bone tumor. The operative findings disclosed many cysts containing bloody fluid and xanthochromic fluid. Numerous multinucleated giant cells, spindle cells, and foam cells were found in the microscopic examination. On the basis of macroscopic and microscopic findings, the patient was diagnosed as having an aneurysmal bone cyst. The aneurysmal bone cyst of the skull is very rare and sixteen cases have been reported in detail. This case had two interesting points, one was the transient impairment of visual acuity and the other was the CT findings.(ABSTRACT TRUNCATED AT 250 WORDS)