The use of molecular markers as an aid in the diagnosis of glandular odontogenic cyst

(1) To investigate the use of p53, Ki67, and PCNA as an aid in the diagnosis of glandular odontogenic cyst (GOC); (2) To compare the expression of these markers in GOC, low-grade mucoepidermoid carcinoma (MEPCa), and radicular cyst with mucous metaplasia (RCM) as an aid in the differential diagnosis; (3) To establish guidelines for the diagnosis of GOC. Study group: 35 patients: 10 GOC, 15 RCM, 9 MEPCa. Immunostaining of archival specimens for p53, Ki67, PCNA. Twenty-nine articles (1987-2004) with detailed histopathological descriptions of GOC, analyzed for frequency of histopathological characteristics. Mean p53 labeling index (LI) was higher in GOC (3.0 ± 4.3%) and MEPCa (4.9 ± 7.4%) than in RCM (0.4 ± 1.2%, p = 0.048). Ki67 LI was higher in GOC (4.4 ± 4.7%) and RCM (3.7 ± 6.7%) than in MEPCa (0.7 ± 1.6%, p = 0.03). There were no significant differences in the expression of PCNA. In the literature, the most consistent histopathological characteristics of GOC included epithelial spherules/"knobs"/whorls (82.8%), cuboidal eosinophilic cells (65.5%), goblet cells (65.5%), intraepithelial glandular/microcystic ducts (58.6%), variations in lining width (55.2%), ciliated cells (51.7%) and mucous pools/mucous-lined crypts (41.4%). These histopathological features were divided into major and minor signs. The diagnosis of GOC should be based on at least the focal presence of the major signs. Measurement of p53 and Ki67 may aid in the differential diagnosis of GOC.