抄録
Dermoid cysts, or congenital inclusion cysts, of the anterior fontanel have been found in various races. However, the occurrence of such cysts seems to be rare in Japanese. This is the seventh reported case from Japan.
This 10-month-old Japanese girl was the product of a normal pregnancy and delivery. At the age of 3 months, a small mass was noted over the vertex of the head which gradually increased in size. She was referred for surgical treatment. There was a round, soft, non-tender mass located over the anterior fontanel, measuring 2.3×2.3×0.5 cm. It was covered with intact skin and was transilluminating. Neurological examination revealed no abnormality. Skull roentgenograms showed a soft tissue mass over the widely opened anterior fontanel. Computerized tomography scan demonstrated an extracranial cystic lesion of heterogeneous density, which was not enhanced by intravenous contrast medium. No intracranial extension was revealed.
The lesion was removed radically through a curvilinear incision from beneath the periosteum. There was no intracranial connection. The cyst contained approximately 0.8 ml of clear and colorless fluid and caseous material. On histological examination, the wall was composed of stratified squamous epithelium supported by collageneous tissue. Hair follicles, and sebaceous and sweat glands were identified. There was no evidence of malignancy.
