Characteristics of calcifying odontogenic cyst in Taiwanese

Calcifying odontogenic cyst (COC) is a rare type of odontogenic cyst. This retrospective study analyzed the clinical, radiographic, and histopathologic features of COC in Taiwanese.

Ten cases of COC in 2 male and 8 female patients with a mean age of 29 years (range, 11 to 48 years) treated from January 1985 to December 2002 were included. Microscopic slides, clinical histories, and radiographic features of these 10 COC cases were reviewed and analyzed.

COCs occurred in the maxilla in 3 cases and in the mandible in 7 cases. COCs were associated with impacted teeth in 6 cases and with odontomas in 3 cases. All COCs appeared as either unilocular (9 cases) or multilocular (1 case) radiolucencies. In 7 cases, spotty radiopaque materials were scattered throughout the radiolucency. Histologically, all of the lesions were at least partially lined by epithelium with cuboidal to columnar basal cells and stellate reticulum-like suprabasal cells. Variable numbers of ghost cells, some of which were calcified, were observed in the lining epithelium or in the fibrous connective tissue wall of all 10 cases. Juxta-epithelial dentinoid was also found in all cases. However, proliferation of ameloblastoma-like tumor nests was observed in only 1 case. Based on the above histologic findings, 6 COC lesions were classified as simple unicystic type, 3 as unicystic odontoma-producing type, and 1 as unicystic ameloblastomatous proliferating type.

COC occurs frequently in the second and third decades and is commonly associated with an impacted tooth or an odontoma. It usually appears as a mixed radiolucent and radiopaque lesion radiographically. Simple unicystic type is the most common type of COC. No recurrences were found after conservative surgical removal in this series.