A survey of tumours of the jawbones in Hong Kong Chinese: 1963-1982.

A total of 114 tumours of the jawbones was confirmed in a survey of 204,583 surgical specimens in Chinese in the University Department of Pathology, Hong Kong from 1963-1982. Odontogenic tumours totalled 82 of which 62 per cent were ameloblastomas. Thus, odontogenic tumours, in particular ameloblastomas, are relatively common in Chinese. In the 51 cases of ameloblastoma, the mean age at presentation in females was significantly younger than in males. Pathological analysis of the ameloblastomas showed the following: (1) connection of tumour epithelium with oral mucosal epithelium suggests a better prognosis; (2) basaloid pattern in the tumour may prognostically indicate a more aggressive biological behaviour; (3) neoplastic infiltration of the grossly normal bone surrounding the tumour mass was frequent; (4) ameloblastomas not uncommonly contained cysts lined by innocuous-looking epithelium; (5) a significant proportion of ameloblastomas appeared grossly as thin-walled unilocular cysts. The implications of these findings in the diagnosis and treatment of ameloblastoma are emphasized.