Differentiated Immunohistochemical Expression of Osteoclastogenic Markers in Radicular Cyst, Odontogenic Keratocyst, and Ameloblastoma.

The aim of this study was to investigate the osteoclastogenesis process by means of immunohistochemical markers for receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), interleukin-6 (IL-6), and cathepsin K (CTSK) antigens in osteolytic lesions of maxillary bones. The sample consisted of 23 radicular cysts (RC), 25 odontogenic keratocysts (OKC), and 25 ameloblastomas (AM). RANKL was statistically higher in RC (49.6±15.2/53.7±18) and OKC (48.6±15.1/51.4±16.8) when compared with AM (37.2±12.5/36.4±13) in the epithelium and connective tissue. OPG was lower in OKC (34.8±18.5) only in connective tissue when compared with RC (44.5±11.2). The expression of RANKL was statistically higher than OPG in RC (epithelium and connective tissue) and OKC (connective tissue). For IL-6, a statistical difference was observed only in the connective tissue between groups, with higher expression in RC (48.2±15) and lower in OKC (22±11.9). The expression of IL-6 was correlated with the intensity of the inflammatory infiltrate. CTSK was statistically higher in AM (34±19) and OKC (29±13.8) compared with RC (19±10.5). According to the results of the present research the bone resorption in cysts and odontogenic tumors occurs through different mechanisms. The ostoclastogenic process in lesions with aggressive clinical behavior, as AM and OKC, seems to be associated with the expression of CTSK. In contrast, lesions with inflammatory etiology, as RC, the expression of IL-6 seems to have an important role in the bone resorption process. The highest expression of RANKL under the expression of OPG also seems to contribute to the growth mechanism of RC and OKC.

Immunohistochemical Expression of MMP-9, TIMP-1, and Vimentin and its Correlation With Inflammatory Reaction and Clinical Parameters in Oral Epithelial Dysplasia.

The aim of this study was to investigate the immunoexpression of matrix metalloproteinase 9 (MMP-9), tissue inhibitor of metalloproteinase 1 (TIMP-1), and vimentin (VIM) and its association with the inflammatory reaction (IR) and clinical parameters in oral epithelial dysplasia (ED). The sample was composed of 66 cases of ED, 27 oral squamous cell carcinoma (OSCC), and 28 non-neoplastic epithelium (NNE). ED was graded according to the binary system as low-risk ED (n=42) and high-risk epithelial dysplasia (HRED: n=24). The IR was defined as the median number of inflammatory cells present on the connective tissue in 5 consecutive fields. Tissue sections of paraffin-embedded samples were immunohistochemically stained; MMP-9 and TIMP-1 expression was analyzed separately in the epithelium and the connective tissue; VIM was analyzed in the epithelium. Clinical parameters such as age, sex, lesion site and clinical presentation, alcohol/tobacco use, and malignant transformation of ED were retrospectively obtained from medical records. Nonhomogeneous leukoplakia presented higher odds (3.857; 95% confidence interval: 1.16-12.85) of being graded as HRED than did homogeneous lesions. The IR was higher in OSCC and ED than in NNE, and correlated with the epithelial expression of VIM. HRED and nonhomogeneous leukoplakias presented higher IR than did low-risk ED and homogeneous leukoplakias. Alcohol users had higher IR than nonalcohol users. Smokers had higher epithelial expression of MMP-9 and VIM. High IR in OSCC and HRED, and its positive correlation with VIM expression suggest a contribution of the IR in the progression of OSCC. Moreover, the high expression of MMP-9 and VIM in smokers implies its involvement in tobacco carcinogenesis.

Diagnostic capability of fine-needle aspiration cytology in assessment of intraosseous lesions of the jaws: A systematic review.

PURPOSE: To systematically review (SR) and critically appraise studies that investigated the diagnostic capability of fine-needle aspiration cytology (FNAC) in the assessment of intraosseous lesions of the jaws. METHODS: Six main electronic databases and three gray literature databases were searched aiming diagnostic studies, which were selected in a two-phase process. Risk of bias (RoB) of included studies was assessed using the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies. RESULTS: A total of eight articles were included, of which six evaluated the FNAC smear technique exclusively, one assessed both smear and cell-block techniques, while one investigated only the cell-block technique. With regard to the FNAC smear technique, from 134 benign lesions investigated, concordance with the histopathological diagnosis was achieved in 64.17% of cases. In addition, considering the 32 malignant lesions assessed through this technique, concordance with histopathology was achieved in all cases. Regarding the cell-block technique, only benign lesions (n = 40) were evaluated in the included studies, in which the concordance rate with histopathology was of 77.5%. The overall RoB judgment was "at risk of bias" for seven included studies mostly due to lack of information or reportedly absence of blinding of evaluator. CONCLUSIONS: Within the limitations of this SR, FNAC presented modest to satisfactory diagnostic capability for the assessment of intraosseous jaw lesions, showing concordance rates higher than 64% for the smear and 77% for the cell-block technique. Also, considerably high concordance rates were found for the assessment of malignant lesions regarding FNAC smear technique.

Podoplanin Expression in Odontogenic Keratocysts Associated or not Associated With Nevoid Basal Cell Carcinoma Syndrome.

BACKGROUND: Podoplanin is a transmembrane glycoprotein expressed on various normal or neoplastic cells. Some studies have shown that podoplanin promotes the migration and invasion of tumor cells. This study evaluated a podoplanin expression in Odontogenic Keratocysts (OKs) associated or not associated with Nevoid Basal Cell Carcinoma Syndrome (NBCCS) and in Orthokeratinized Odontogenic Cysts (OOCs). MATERIALS AND METHODS: A total of 50 lesions were obtained in this study, 28 OKs, 18 OKs associated with NBCCS, and 4 OOCs. Immunohistochemical expression of podoplanin in epithelial cells was evaluated using the following score: (a) intensity of immunostaining: (0: absent, 1: weak, 2: moderate, 3: strong, and 4: very strong) and (b) number of positively cells (0: 0%, 1: <25%, 2: 25% to 50%, 3: 50% to 75%, and 4: >75%). The final score was determined by adding the scores of a and b and ranged from 0 to 8 (0: absent, 1 to 4: weak, and 5 to 8: strong). RESULTS: Podoplanin expression was significantly stronger in the basal layer OKs and NBCCS lesions. Further, podoplanin expression was the highest in the suprabasal layer of NBCCS lesions, followed by the suprabasal layers of OK and OOC lesions. CONCLUSIONS: Podoplanin expression is different in lesions of different biological behaviors. Podoplanin seems to play a role in cell proliferation and migration.

Association between immunohistochemical expression of matrix metalloproteinases and metastasis in oral squamous cell carcinoma: Systematic review and meta-analysis.

BACKGROUND: The aim of this systematic review (SR) was to summarize and critically appraise available evidence on the association of the immunohistochemical expression of matrix metalloproteinases (MMPs) with the occurrence of lymph node/distant metastasis of oral squamous cell carcinoma (OSCC). METHODS: Searches were conducted in five main electronic and three gray literature databases. RESULTS: From 2128 records identified, 50 were included for qualitative analysis. A total of 12 MMPs were identified (-1, -2, -3, -7, -8, -9, -10, -11, -13, -25, -26, and MT1-MMP). Most included studies reported a positive association of MMP-1, -2, -3, -7, -9, and MT1-MMP with lymph node metastasis. MMP-8, -25, and -26 were not associated with lymph node metastasis. CONCLUSIONS: According to this SR, MMP-1, -2, -3, -7, -9, and MT1-MMP seem to play an important role in lymph node metastasis of OSCC.

Calcifying epithelial odontogenic tumours: Collaborative study of 32 cases and review of literature.

OBJECTIVES: To analyse the occurrence of calcifying epithelial odontogenic tumours (CEOT) based on biopsy records from different Brazilian geographic regions and to contrast the data with a review of the literature. MATERIALS AND METHODS: A 2-step study was conducted. Step 1 consisted of a collaborative study of biopsies obtained from 1953 to 2017 at six Brazilian oral and maxillofacial pathology centres. Evaluation of 86,268 biopsy records was performed. Demographic and histopathological diagnosis data were assessed. In Step 2, a review of the literature of case reports and cases series of CEOT identified across five electronic databases was conducted. RESULTS: In the collaborative study, 32 cases of CEOT were evaluated. This figure represented 0.03% of the oral and maxillofacial lesions and 1.7% of all odontogenic tumours across the centres. Women in the fourth decade of life were more affected. CEOT occurred more in the mandible than in the maxilla (ratio 1.9:1). The review of the literature showed that Asian individuals were more affected by this neoplasm. CONCLUSIONS: Useful knowledge on the epidemiology, treatment and follow-up of CEOT has been provided. Demographic data and clinical features of the cases presented in this collaborative study were quite similar to those of studies reported worldwide.

Immunohistochemical analysis of matrix metalloproteinases (1, 2, and 9), Ki-67, and myofibroblasts in keratocystic odontogenic tumors and pericoronal follicles.

BACKGROUND: Keratocystic odontogenic tumor (KCOT) is a benign tumor that arises sporadically or associated with nevoid basal cell carcinoma syndrome (NBCCS). Its locally aggressive behavior contrasts with its cystic histological appearance. To better understand the interaction between tumor cells and the stroma, the present study aimed to evaluate and compare the immunohistochemical expression of matrix metalloproteinases (MMP-1, -2, and -9), the cellular proliferation index (Ki-67), and the presence of myofibroblasts (MFs) in KCOTs. METHODS: Eleven cases of isolated KCOT (G1) and 12 cases of KCOT associated with NBCCS (G2) were selected for an immunohistochemical investigation of the proteins MMP-1, MMP-2, MMP-9, Ki-67, and α-smooth muscle actin (α-SMA) in MFs. A group of 6 pericoronal follicles (G3) was included as a normal odontogenic tissue control. RESULTS: Significant differences between the G3 and G1/G2 groups regarding the expression of MMP-1, MMP-9 (in connective tissue), and Ki-67 were observed. In KCOT, there was a positive correlation between the Ki-67 antigen and MMP-1 and between MFs and MMP-1 in the parenchyma. No statistical differences were found between G1 and G2 groups. CONCLUSIONS: MMP-1, MMP-9, and proliferative activity appear to play important roles in KCOT pathogenesis. The increased proliferative activity with KCOT was associated with elevated MMP-1 production in the parenchyma, which influenced the growth of the lesion in association with an increased number of MFs.

An image processing software applied to oral pathology.

This study presents the development and evaluation of an image processing software for computer-assisted cellular structure counting. The proposed software consists of a set of processing and analytical tools which allows its use in several applications of cell and cellular structure counting. A particular application in AgNOR quantitative analysis is presented. The knowledge obtained from experienced pathologists has been codified in a sequence of processing steps in order to allow automatic estimation of the mean number of AgNORs per cell in ameloblastomas. The performance of the presented software in such application was verified by comparing the data provided by visual analysis, by two observers previously calibrated and under supervision of two experienced specialists (Group 1) and by the computer program (Group 2). No statistical difference was observed (p<0.05) between the two groups. The use of the proposed method in AgNOR applications permitted attainment of accurate and precise data without the difficulties frequently found in the traditional visual analysis method (time, training and subjectivity). The developed software is an interesting tool as an aid in the study (estimation of the number of cells and cellular structures) of malignant and benign neoplasms.

Loss of heterozygosity of the APC gene in oral squamous cell carcinoma.

The aim of this study was to investigate loss of heterozygosity (LOH) of the APC tumor suppressor gene loci, using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) in 40 cases of oral squamous cell carcinoma (OSCC). Observed informativity was 72.5% for APC exon 11 and 82.5% for APC exon 15. LOH at APC exon 11 was observed in 2 (6.9%) of 29 informative cases, and no LOH was observed for APC exon 15. Our results suggest that inactivation of the APC gene plays a minor role in the carcinogenesis of OSCC.

Simple salting-out method for DNA extraction from formalin-fixed, paraffin-embedded tissues.

The aim of this study was to standardize a method of DNA extraction from formalin-fixed and paraffin-embedded tissues (PETs) using a salt solution to precipitate protein and isopropanol to precipitate DNA. The samples were submitted to a DNA extraction method in which two different concentrations of ammonium acetate (2 and 4M) were compared with a phenol-chloroform extraction method and with a commercial DNA isolation kit. DNA was qualified and quantified by spectrophotometer analysis, electrophoresis, and amplification by PCR. The 167 and 268bp fragments of APC and beta-globin genes, respectively, were amplified equally from DNA extracted by all tested methods and in all cases. However, the 536bp fragment of beta-globin gene was not amplified in all cases. According to our results, the extraction method using ammonium acetate proved to be simple and suitable for obtaining DNA of good quality, which can be easily amplified by PCR.