[Adenomatoid odontogenic tumor in calcifying odontogenic cyst].

BACKGROUND: Adenomatoid odontogenic tumors (AOT) and calcifying odontogenic cysts (COC, Gorlin's cyst) are rare benign specificities of odontogenic tumors. Most odontogenic tumors are lesions of embryonic odontogenic tissue. Radiographically, odontogenic tumors may mimic an odontogenic follicular cyst. CASE REPORT: This paper describes the case of an 11-year-old female patient with a remarkable combination of these two entities. The lesions were found at the site of a retained first premolar and a persistent deciduous tooth 84 of the right lower jaw. Without clinical symptoms the tumor had expanded the vestibular cortical bone of the premolar region. Radiographically, the lesion appeared as a typical follicular cyst. During the operation, excochleation of the cyst was performed and the premolar was extracted. Finally, the epithelium of the cyst was treated by curettage. The histologic specimen revealed the diagnosis of an adenomatoid odontogenic tumor (AOT) in a calcifying odontogenic cyst (COC). DISCUSSION: The described case shows that symptoms of odontogenic tumors are usually nonspecific. For that reason one should always take a biopsy for histological investigation when patients present atypical cysts of the jaw. In rare cases even malignant odontogenic neoplasms could occur.