[Aneurysmal bone cyst of the frontal bone (author's transl)].

A six year-old boy. He complained of a swelling of the left forehead since October of 1971, the region of his upper eyelid has then been gradually swollen. He was admitted to our institute on the 24th of February, 1973, without the past history of head trauma. We found that the swollen region had a diameter of about 4 centimeters covered from the left upper eyelid to the forehead with a slight tenderness on pressure. We had no neurological findings. According to the results of skull X rays, the superior margin of left orbit and zygomatic process of frontal bone were swollen and like honey combs. An irregular, long and narrow osteolytic legion was found, which was about 4 centimeters long and 5 centimeters wide. According to the results of the left selective external carotid angiography, after injection of 60% Urografin, for more than 2.5- 10 seconds, at the left frontal bone an abnormal shadow (patchy contrast filling) was noted, which was about 4 centimeters long and 5 centimeters wide. After the direct injection of Urografid into the lesion, the cyst of one centimeter long and 3 centimeters wide was observed at the zygomatic process of the frontal bone. Operation was performed to excise the outer plate of the swollen bone and to curette the lesion after the ligature of the left external carotid artery. Histological examination showed many blood lakes and some multinuclear giant cells in the specimens and we diagnosed it was an aneurysmall bone cyst. This case is the first one of aneurysmall bone cyst confirmed by the selective external carotid angiography and the direct puncture of lesion.