Thirteen cases of odontogenic keratocysts were studied clinically, histopathologically and immunohistochemically to clarify the features and to investigate the mechanism of recurrence.
The patient group consisted of 8 males and 5 females. They ranged in age from 17 to 76, with a mean of 49.4 years. The lesions of 13 cases occurred in the mandible, and especially 4 cases in the third molar area of the mandible. radiographic examination showed 7 multi-locular and 6 unilocular appearance.
Enucliation followed by peripheral osteotomy with a rotary instrument was carried out for all cases. Recurrence was observed only for one case so far.
The epithelium for all cases was keratinized histopathologically. The cyst wall of 7 cases was a thin, band-like lining of stratified squamous epithelium without rete rigde. No satellite cyst was observed for all cases.
The localization of cytokeratin 10/13, 8, 10, 18, 19 and 20 were studied immunohistochemically on 6 cases. The positive reactivity for cytokeratin 10/13 was detected in the cyst wall lining on 2 cases of 6, cytokeratin 8 on 3 of 6, cytokeratin 10 on 2 of 5, cytokeratin 18 on 4 of 6, and cytokeratin 19 on 2 of 6, respectively. But, no reactivity for cytokeratin 20 was observed in that of 5 cases investigated.
There thought to be a tendency that cytokeratin 18 might be found in the cyst wall of younger patients immunohistochemically, while cytokeratin 10 in that of elderly ones.
The lining epithelium was also evaluated immunohistochemically for Ki-67, EGF, bcl-2, and c-myc without any of those positive reactivity in all cases investigated, except one positive reaction for c-myc protein.