Several studies have indicated that increased levels of insulin-like growth factor 1 (IGF-I) or altered levels of its binding proteins are associated with an increased risk of the most common cancers, including cancers of the colorectal, lung, breast and prostate. The aim of this study is to investigate the expression of IGF-1 in both calcifying epithelial odontogenic tumor (CEOT) and ameloblastoma.
UNASSIGNED: The research sample consisted of 23 paraffin block from Oral Pathology Department, Faculty of Dentistry, Damascus University, including six biopsies of CEOT, two biopsies of the plexiform ameloblastoma and 14 biopsies of the follicular ameloblastoma. All specimen were prepared and immunostained with rabbit polyclonal antibody to IGF-1. Immunostaining was assessed according to German-semiquantitative scoring system, and then the results were aggregated and statistically analyzed using SPSS version 13.0 (Student\'s test for two independent samples, one-way analysis of variance, Kruskal-Wallis test and Mann-Whitney U-test), the significance level P value less than 0.05 was considered statistically significant.
UNASSIGNED: All CEOT and ameloblastoma samples were positive for IGF-1 staining, except one sample of ameloblastoma, which was negative. The results showed that there were no statistically significant differences between CEOT and ameloblastoma in the values of IGF-1 expression (P=0.993) and IGF-1 expression rates (P=0.874) and in the frequency of IGF-1 expression (P=0.761) and IGF-1 staining intensity score (P=0.731).
UNASSIGNED: IGF-1 plays an important role in the growth of odontogenic tumors and there are no differences in IGF-1 expression between CEOT and ameloblastoma.

BACKGROUND: Calcifying epithelial odontogenic tumor (CEOT) is a rare benign neoplasia, locally aggressive, that tends to invade bone and adjacent soft tissues. This case report describes the thirteenth known case of CEOT with maxillary sinus extension and the second one that also involves the buccal vestibule mucosa with peculiar histopathological and immunohistochemical data.
METHODS: Here we report the case of a 45-year-old female with a CEOT diagnosed and treated at the Oral & Maxillofacial Surgery Department, County Clinical Emergency Hospital of Craiova, Romania. The clinical and imaging investigation revealed an intraosseous tumor developed from the left posterior maxilla with maxillary sinus and buccal vestibule mucosa extension. Histopathology found an epithelium-rich CEOT variant, but with scattered S100 positive clear cells, focal small rounded cementum-like deposits and areas with some degree of nuclear pleomorphism. The immunohistochemical investigations emphasised its local aggressiveness behavior with involvement of multiple molecular mechanisms that underlie tumor invasiveness. A subtotal maxillectomy was performed followed by defect reconstruction.
CONCLUSIONS: We discuss the relevant clinicopathological features of an aggressive rare case of CEOT with maxillary sinus extension and buccal vestibule mucosa involvement. The immunohistochemical study suggests its utility in attempting to assess the degree of local tumor aggressiveness and thus in adopting the most efficient therapeutic attitude.