Abstract
AIM: The present study aimed to contribute to the biological characterization of odontogenic ghost cell lesions (OGCL). MATERIALS AND METHODS: Sixty-nine OGCL consisting of 60 calcifying odontogenic cysts (COC) and nine dentinogenic ghost cell tumors (DGCT) were collected from a single center over a period of 63 years. The clinical, radiographic, and histopathological features were re-evaluated. Histochemical and immunohistochemical studies were performed in 37 COC and three DGCT. Molecular studies were performed in 17 COC to identify possible CTNNB1 gene mutations. RESULTS: COC was more frequent in women, in the second decade of life, involved the anterior region of both jaws, and manifested mainly as a unilocular radiolucency. DGCT was more frequent in women, in the ninth decade of life, involved the anterior region of mandible, and manifested as irregular mixed lesions. The ameloblastic/ameloblastomatous epithelium and ghost cells stained positive for AE1-AE3 (40/40), amelogenin (40/40), β-catenin (40/40), E-cadherin (40/40), S100 (22/40), and vimentin (15/40) in both the studied entities. TOM-20 (40/40), BCL-2 (40/40), BRAF V600E (4/40), and p63 (1/40) were only positive in the ameloblastic/ameloblastomatous epithelium, and lysozyme (40/40) and CD68 (35/40) were positive in the ghost cells. No single-nucleotide variants were detected in CTNNB1, except for a change at codon 38. CONCLUSIONS: The protein immuno-expression observed in ghost cells confirms an epithelial origin and suggests that these cells result from a degenerative process involving an increase in lysosomes and accumulation of proteins. Immuno-expression of β-catenin in the absence of CTNNB1 mutations suggests the presence of mutations in other genes associated with the WNT/β-catenin pathway.