Retrospective study of 289 odontogenic tumors in a Brazilian population.

BACKGROUND: Odontogenic tumors (OTs) are considered important among oral lesions because of their clinicopathological heterogeneity, and variable biological behavior. This paper aims to determine the frequency and distribution of OTs, over a period of 10 years, at a public university in Northeastern Brazil and compare this data with previous reports. MATERIAL AND METHODS: We reviewed all cases of OTs from oral pathology laboratory of University of Pernambuco (UPE), from 2004 to 2014. Diagnoses were re-evaluated and the tumors were classified according to the latest (2005) World Health Organization Classification of Tumors. In addition, we searched in the English-language literature retrospective studies on OTs that used the same classification. RESULTS: Within the total of 6028 oral biopsies, 289 (4.79%) were OTs. Of these, 287 (99.3%) were benign and 2 (0.7%) were malignant. The overall incidence was 31.1/million. Mandible-maxilla ratio was 2.5:1 and mean age 35 years. Keratocystic odontogenic tumor (KCOT) (34.6%) was the most frequent lesion, followed by ameloblastoma (AMB) (32.9%) and odontoma (ODO) (11.4%). CONCLUSIONS: OTs are uncommon neoplasms with geographic variation. Our clinicopathological features are according to literature. In the present study, KCOT was the most frequent one, showing that the new classification of OTs altered the distribution of these lesions and possibly made KCOT the most common OT observed in diagnostic services worldwide.

Immunoexpression of MMPs-1, -2, and -9 in ameloblastoma and odontogenic adenomatoid tumor.

OBJECTIVE: The aim of this study was to evaluate and compare the expression of metalloproteinases-1, -2, and -9 in solid ameloblastoma and adenomatoid odontogenic tumor. METHODS: A total of 20 cases of solid ameloblastoma and 10 cases of adenomatoid odontogenic tumors were selected and immunohistochemically assessed. Metalloproteinases-1, -2, and -9 immunoexpression and their distribution pattern were noted and semiquantitatively scored. The scores obtained were statistically analyzed. RESULTS: Matrix metalloproteinase (MMP)-1 showed a predominant expression in both tumors and was found in stroma and parenchyma. For MMP-2, there was a varied expression, with 80% and 60% of immunoreactive tumor cells in ameloblastoma and adenomatoid odontogenic tumor respectively. Regarding stromal cells, 65% of ameloblastomas and 80% of adenomatoid odontogenic tumors showed positivity. There was immunoexpression of the MMP-9 in parenchymal and stromal cells in all cases of both tumors analyzed. A statistically significant difference in the expression of MMP-1 in relation to the expression of MMP-2 and -9 in ameloblastomas (P < 0.001) was observed. CONCLUSION: The results suggest that these metalloproteinases are related to growth and progression of tumors analyzed, and particularly in ameloblastoma, its highest aggressiveness may be, in part, a result of the active participation of the stromal cells and their products, such as the MMPs studied.