Dedifferentiation of odontogenic keratocyst epithelium after cyst decompression

Cytokeratin-10 expression by cystic epithelium has been shown in the suprabasilar layers of odontogenic keratocyts (OKCs) but not in dentigerous cysts. Cyst decompression and irrigation result in the loss of keratinization. In this study, we used cytokeratin-10 antibody staining to evaluate changes in OKC epithelium to determine if decompression/irrigation treatment results in an epithelial modulation that may be associated with lower long-term recurrence.

Fourteen OKCs were exteriorized by removal of mucosa and bone. An irrigation port was placed into the cyst for twice-daily irrigations. At 3-month intervals, panoramic radiographs were obtained and cyst-lining cells were sampled and stained for cytokeratin-10. Residual cystectomy was performed when necessary based on clinical and radiographic criteria, and the lining was evaluated by histologic and immunohistochemical examination.

There were 6 males and 8 females with a mean age of 32 years. Ten cysts were mandibular, and 4 were maxillary. Average duration of irrigation was 8.4 months (range, 6 to 12 months), and the mean shrinkage of the radiolucency was 65% (range, 5% to 91%). All cytologic samples obtained at 3 and 6 months contained cytokeratin-10-positive epithelial cells. At the time of cystectomy, 9 of 14 cases were cytokeratin-10 negative and no longer showed histologic features of OKCs. Specimens from the remaining 5 patients were histologically consistent with OKC and were cytokeratin-10 positive. Mean treatment time of the cytokeratin-10-positive group was 7 months, and that of the cytokeratin-10-negative group was 9 months.

Epithelial dedifferentiation and loss of cytokeratin-10 production were observed in 64% of patients treated by cyst decompression/irrigation after a 9-month average treatment time. Longitudinal follow-up of these patients will determine whether this change is associated with lower rates of recurrence than alternative OKC therapy.