Histopathological analysis of 30 specimens of glandular odontogenic cyst.

Glandular odontogenic cysts (GOC) are relatively rare, and require differentiation from radicular cysts, dentigerous cysts, and central mucoepidermoid carcinoma of jawbone. We conducted clinical, histopathological, and immunohistochemical analysis to elucidate the relationship between the clinical behavior and histopathological features, as well as the origin of tissues and factors related to the development of GOC. Thirty specimens from 29 patients (19 males, 11 females; mean age 51.8, range 18-85 years) diagnosed histopathologically with GOC were studied. By location site, mandibular molar region was most common (17 cysts), followed by maxillary anterior region (5), maxillary molar region (4), and mandibular anterior region (4). All cases were clinically asymptomatic and were detected incidentally on X-ray examination. In the X-ray findings, all cases showed unilocular, well-defined radiolucencies, with a long diameter ranging from 9 to 36 mm. Histopathologically, eosinophilic cuboidal cells and microcysts were found in all cases, apocrine snouting was observed in 27 (90%), clear cells in 28 (93.3%), variable thickness of epithelial lining in 29 (96.7%), and mucous cells (both PAS and d-PAS positive) in 29 (96.7%). These six histopathological features were useful for histopathological diagnosis. There was one case of multiple metachronous bilateral mandibular lesions and one case of a locally aggressive type. Immunohistochemical staining showed CK19 positivity and BRAF positivity in all cases, and CK18 positivity in 24 (80%). Ki-67 was positive in the lining epithelium of a locally aggressive case, but positive cells were rare in other cases. CK19 positivity in all cases indicate that GOCs were derived from odontogenic epithelium; and BRAF positivity suggests involvement of this gene mutation in GOC development. Ki-67 positivity may indicate locally aggressive type, which warrants further study.