Clinicopathological significance of SNPs in RAD51 and XRCC3 in oral and oropharyngeal carcinomas.

BACKGROUND: This study investigated the influence of single nucleotide polymorphisms (SNP) in RAD51 and XRCC3 on susceptibility to oral and oropharyngeal squamous cell carcinomas (SCC) and determined their clinicopathological significance. SUBJECTS AND METHODS: SNPs rs1801320 and rs1801321 in RAD51 and rs861539 in XRCC3 were genotyped in 81 patients presenting oral SCC, 45 presenting oropharyngeal SCC, and 130 healthy controls, using TaqMan allelic discrimination assays. Multiple logistic regression models were used to explore the association between SNPs and cancer development, as well as gene-gene (GxG) interaction and gene-environmental factor (GxE) interaction. Clinicopathological associations were verified through the chi-square test, and univariate and multivariate methods were applied for survival analyses. RESULTS: Although allelic and genotypic models and the GxG interaction analysis were nonsignificant, the GxE analysis revealed synergistic effects of the risk alleles of rs1801320, rs1801321, and rs861539 with smoking and alcohol consumption on susceptibility to oral and oropharyngeal SCC. Furthermore, oropharyngeal SCC patients carrying the XRCC3 rs861539 GT/TT genotype (T risk allele) presented a shorter overall survival than GG genotype carriers. CONCLUSION: Combined effects of RAD51 (rs1801320 and rs1801321) and XRCC3 (rs861539) SNPs with environmental carcinogens (tobacco and alcohol) are associated with oral and oropharyngeal SCC development.

Oral lichen sclerosus: a rare case and update.

Lichen sclerosus (LS) is a chronic inflammatory mucocutaneous disease that often affects the anogenital area; oral mucosal lesions are extremely rare. A 52-year-old woman presented for evaluation of an 8-year history of a persistent whitish plaque in the buccal mucosa. Intraoral examination revealed multiple elevated whitish plaques diffusely distributed in the buccal mucosa associated with an area of tissue atrophy. Although both leukoplakia and lichen planus were considered, incisional biopsy and later, full excision confirmed the histopathological diagnosis of oral LS. After 6 months of follow-up, there are no clinical signs of relapse. This case highlights the importance of clinical and histopathological findings for the correct diagnosis and treatment of oral LS.

Multinucleated giant cell reaction in lower lip squamous cell carcinoma: a clinical, morphological, and immunohistochemical study.

BACKGROUND: Multinucleated giant cell (MGC) reactions have been identified in several malignancies, but their frequency and significance in lower lip squamous cell carcinoma (SCC) are not established. This study evaluated the MGC reactions and their association with clinicopathological parameters in lower lip SCCs. The polarization profile of these cells (M1 or M2 macrophages) was also assessed. METHODS: The presence and distribution of MGC reactions in high-power fields (400×) were evaluated in hematoxylin/eosin-stained histological sections of 91 lower lip SCCs. The histopathological grade of malignancy was evaluated using two grading systems (World Health Organization [WHO] and Malignancy Grading of the Deep Invasive Margins). The histiocytic nature (CD68) and polarization profile (M1-HLA-DR+ or M2-CD163+) of MGCs were evaluated by immunohistochemistry. RESULTS: Multinucleated giant cell reaction was identified in 36 (39.6%) cases, and its frequency was 3.3 times higher in well/moderately differentiated tumors than in poorly differentiated tumors (WHO grading system) (P = 0.006). For Malignancy Grading of the Deep Invasive Margins, the frequency was 2.03 times higher in highly/moderately keratinized tumors than in tumors with minimal/no keratinization (P = 0.012). No significant associations were observed between the presence/distribution of MGCs and clinical parameters (tumor size, lymph node metastasis, distant metastasis, and clinical stage) (P > 0.05). All MGCs were positive for CD68 and there was a predominance of HLA-DR+ over CD163+ MGCs (P = 0.031). CONCLUSIONS: Multinucleated giant cell reactions may not be involved in tumor progression in lower lip SCCs. In this microenvironment, MGCs tend to exhibit a predominantly M1 phenotype and may represent a foreign body reaction to SCC keratin pearls.

Clinical findings and risk factors to oral squamous cell carcinoma in young patients: A 12-year retrospective analysis.

BACKGROUND: In recent years have been observed an increased incidence of OSCC in young individuals. Based on this, the aim this study was to describe the clinical characteristics of all cases of OSCC in younger patients, diagnosed in two oncology referral hospitals, at the northeast region of Brazil within a 12-year period. MATERIAL AND METHODS: Data regarding general characteristics of patients (age, gender and tobacco and/or alcohol habits) and information about the lesions (tumor location, size, regional lymph node metastasis, distant metastasis and clinical stage) were submitted to descriptive and inferential analysis. Statistical analysis included Chi-square and Fisher's exact tests (P<0.05). RESULTS: Out of 2311 registered cases of OSCC, 76 (3.3%) corresponded to OSCC in patients under 45 years old. Most of them were male (n=62, 81.6%) and tobacco and/or alcohol users (n=40, 52.8%). The most frequent site was the tongue (n=31, 40.8%), with predominance of cases classified at advanced clinical stage (III and IV, n = 46, 60.5%). The advanced stage of OSCC (III and IV) was statistically associated with male gender (P=0.035), lower education level (P=0.007), intraoral sites (P<0.001), presence of pain symptomatology (P=0.006), and consumption of tobacco and/or alcohol (P=0.001). CONCLUSIONS: The profile of OSCC in young patients resembles to the commonly characteristics reported for overall population. The late diagnosis in young patients usually results in poor prognosis, associated with gender, harmful habits and tumor location. Although prevalence is low, stimulus to prevention and to early diagnosis should be addressed to young individuals exposed to risk factors.

Immunohistochemical analysis of SHH, SMO and GLI-1 proteins in epithelial odontogenic lesions.

The present study analyzed the expression of proteins involved in the sonic hedgehog signaling pathway (SHH, SMO, and GLI-1) in benign epithelial odontogenic lesions (odontogenic keratocyst - OKC, ameloblastoma - AB, and adenomatoid odontogenic tumor - AOT) in order to identify the role of these proteins in the pathogenesis of these lesions. The sample consisted of 20 OKCs, 20 ABs, and 10 AOTs. The Kruskal-Wallis, Mann-Whitney U, and Spearman's (r) tests were used for statistical analysis, with the level of significance set at 5% (p < 0.05). The membrane/cytoplasmic expression of SHH was significantly higher in AB compared to AOT (p = 0.022) and OKC (p = 0.02). No differences were found in the membrane/cytoplasmic expression of SMO between the lesions studied. Regarding GLI-1, significant differences were observed at the nuclear level for AB and OKC compared to AOT (p < 0.0001). In addition, significant positive correlations were found between cytoplasmic and nuclear GLI-1 in AB (r = 0.482; p = 0.031) and OKC (r = 0.865; p < 0.0001), and between membrane/cytoplasmic SMO and cytoplasmic GLI-1 in AOT (r = 0.667; p = 0.035) and OKC (r = 0.535; p = 0.015). The results of this study confirm the participation of the sonic hedgehog signaling pathway in the pathogenesis of the lesions studied. Overexpression of SHH in ABs and nuclear expression of GLI-1 in ABs and OKCs indicate that these proteins contribute to the more aggressive behavior of these two lesions when compared to AOT.

Immunohistochemical expression of DNA repair proteins in oral tongue and lower lip squamous cell carcinoma.

The DNA repair system involves genes and proteins that are essential for the maintenance of genome integrity and the consequent control of various cellular processes. Alterations in these genes and proteins play a role in tumor development and progression and might be associated with prognosis. The aims of this study were to analyze the immunoexpression of two DNA repair proteins, XPF and XRCC1, in lower lip squamous cell carcinoma (LLSCC) and oral tongue squamous cell carcinoma (OTSCC), and to investigate possible associations with clinical and histopathological parameters. The immunohistochemical expression of XPF and XRCC1 was analyzed semi-quantitatively in 40 cases each of LLSCC and OTSCC. The chi-squared test or Fisher's exact test, when appropriate, was used to investigate the association between expression of the proteins and clinicopathological characteristics. The cytoplasmic immunoexpression of XPF was high in OTSCC (95% of the cases analyzed) but low in LLSCC (52.5%). Among the clinicopathological parameters evaluated, a statistically significant association was observed between high nuclear expression of XRCC1 and the absence of regional lymph node metastasis in patients diagnosed with OTSCC (p=0.006). The high protein expression of XPF and XRCC1 in OTSCC and LLSCC suggests an important role in the development and progression of these tumors. Our study found an association between high nuclear expression of XRCC1 and the absence of loco-regional metastasis in cases diagnosed as OTSCC, suggesting a role of this protein in tumor progression.

Role of Twist and Podoplanin in Partial Epithelial-Mesenchymal Transition in Oral Squamous Cell Carcinoma.

The aim of this study was to perform a comparative analysis of podoplanin (PDPN) and Twist immunoexpressions in lower lip and oral tongue squamous cell carcinomas (LLSCC and OTSCC, respectively). PDPN and Twist immunoexpressions were semi-quantitatively evaluated by analyzing the invasion front, the compressive areas, the large islands and nests and dissociated cells of the chosen carcinomas. Their statistical associations and correlations with clinical-pathological characteristics were verified by the Mann-Whitney and Spearman's test. Twist expression was low in both carcinomas, with <25% labeling on the invasive front. Significant differences were observed for LLSCC (p=0.032) and OTSCC (p=0.025) regarding PDPN immunoexpression in relation to the worst invasion patterns determined by a histological malignancy gradation system. Statistically significant negative correlations between PDPN membrane expression and general (r=-0.356, p=0.024) and cytoplasmic Twist expressions (r=-0.336; p=0.034) in LLSCC were also observed. Twist and PDPN are suggested to be associated to a more aggressive invasion pattern in both LLSCC and OTSCC cases but not related to the different biological behaviors on these anatomical sites. Also, it was seen that PDPN membrane expression is inversely related to general and cytoplasmic Twist expression in LLSCC cases.

Immunoexpression of DNA base excision repair and nucleotide excision repair proteins in ameloblastomas, syndromic and non-syndromic odontogenic keratocysts and dentigerous cysts.

OBJECTIVE: To evaluate the immunoexpression of DNA base excision repair (BER) [apurinic/apyrimidinic endonuclease 1 (APE-1), X-ray repair cross complementing 1 (XRCC-1)] and nucleotide excision repair (NER) [xeroderma pigmentosum complementation group (XPF)] proteins in benign epithelial odontogenic lesions with different biological behaviors. DESIGN: Thirty solid ameloblastomas, 30 non-syndromic odontogenic keratocysts (NSOKCs), 29 syndromic odontogenic keratocysts (SKOCs), 30 dentigerous cysts (DCs) and 20 dental follicles (DFs) were evaluated quantitatively for APE-1, XRCC-1 and XPF through immunohistochemistry. RESULTS: Nuclear expression of APE-1 was significantly higher in NSOKCs, SOKCs, and ameloblastomas in comparison to DCs (p < 0.001). Nuclear expression of XRCC-1 was higher in NSOKCs and SOKCs than in DCs (p < 0.05). At the nuclear level, XPF expression was higher in NSOKCs and SOKCs than in DCs and ameloblastomas (p < 0.05). A statistically significant higher expression of APE-1 (nuclear), XRCC-1 (nuclear), and XPF (nuclear and cytoplasmic) was found in all odontogenic lesion samples as compared to DFs (p < 0.05). For all lesions, there was a positive correlation between nuclear expression of APE-1 and XRCC-1 or XPF (p < 0.05). CONCLUSIONS: Our results suggest a potential involvement of APE-1, XRCC-1 and XPF proteins in the pathogenesis of benign epithelial odontogenic lesions, especially in those with more aggressive biological behavior, such as ameloblastomas, NSOKCs, and SOKCs. We also showed that the expression of APE-1 was positively correlated with the nuclear expression of XRCC-1 and XPF, which may suggest an interaction between the BER and NER pathways in all odontogenic lesions studied herein.

Immunohistochemical evaluation of HLA-G and FoxP3+ T regulatory cells in oral cavity and lower lip squamous cell carcinomas.

Human Leukocyte Antigen G (HLA-G) is a molecule involved in the tumor immunosuppression and also in the generation of regulatory T (Treg) cells, thus leading to evasion to the immune system host, and consequently, contributing to tumor progression in several cancers. The aim of this study was to evaluate the immunoexpression of HLA-G by tumor cells and FoxP3+ Treg cells in 25 oral tongue squamous cell carcinomas (SCCs) and 25 lower lip SCCs and analyze their relationship with clinical parameters. HLA-G expression was higher in oral tongue SCCs than in lower lip SCCs. In oral tongue SCCs and lower lip SCCs, no association between HLA-G expression and clinical parameters (tumor size, lymph node status, distant metastasis, and clinical stage) was verified (P>0.05). FoxP3+ Treg cells were detected along the tumor invasive front in all cases of oral tongue and lower lip SCCs. In oral tongue SCC cases, the number of Treg cells tended to be higher in smaller tumors, tumors without regional lymph node metastasis, and tumors in early clinical stages, but the difference was not statistically significant (P>0.05). A significant positive correlation was found between the expression of HLA-G by neoplastic cells and Treg cells in lower lip SCCs (p = 0.008). Our findings suggest the involvement of HLA-G and Treg cells in the modulation of immune responses in oral tongue and lower lip SCCs. This interaction between HLA-G and Treg cells may represent an evasion mechanism in these malignancies.

Association of polymorphisms in IL-8, MMP-1 and MMP-13 with the risk and prognosis of oral and oropharyngeal squamous cell carcinoma.

OBJECTIVE: This study investigated the risk and prognostic value of single nucleotide polymorphisms (SNP) inIL-8, MMP-1 and MMP-13 in oral and oropharyngeal squamous cell carcinomas (SCCs). DESIGN: SNPs rs2227532 and rs4073 inIL-8, rs2071230 and rs470558 in MMP-1, and rs2252070 in MMP-13 were genotyped in 125 oral and oropharyngeal SCC patients and 130 healthy controls, using TaqMan allelic discrimination assays. Multiple logistic regression models were used to explore the association between SNPs and cancer development, as well as SNP-SNP interaction and gene-environmental factor (GxE) interaction. Univariate and multivariate methods were applied for survival analyses. RESULTS: With exception of rs2227532, all the SNPs were in Hardy-Weinberg equilibrium in the control. No associations between rs4073 in IL-8 and rs2071230 and rs470558 in MMP-1 were observed, but rs2252070 in MMP-13, in the dominant model, was associated in a protective manner to oral and oropharyngeal SCC (OR: 0.20, 95% CI: 0.06-0.71, p = 0.007). All SNPs interact significantly with cigarette smoking and alcohol consumption on susceptibility to oral and oropharyngeal SCC, but they showed no influence on survival of the patients. CONCLUSIONS: Our results show that rs2252070 inMMP-13 may confer protection effect against oral and oropharyngeal SCC. In addition, the combined effects of IL-8 (rs4073), MMP-1 (rs2071230 and rs470558) and MMP-13 (rs2252070) with environmental carcinogens, such as tobacco and alcohol, are related to increased risk for oral and oropharyngeal SCC development.

Immunoexpression of human leukocyte antigen-DR in actinic cheilitis and lower lip squamous cell carcinoma.

The aim of this study was to evaluate the immunoexpression of human leukocyte antigen-DR (HLA-DR) in actinic cheilitis (AC) and lower lip squamous cell carcinoma (LLSCC), and to correlate the findings with clinical (tumor size/extent, regional lymph node metastasis, and clinical stage) and histopathological (grade of epithelial dysplasia and inflammatory infiltrate for AC and histopathological grade of malignancy for LLSCC) parameters. Twenty-four AC and 48 LLSCC cases (24 with regional nodal metastasis and 24 without regional nodal metastasis) were selected. The scores of immunopositive cells for HLA-DR in the epithelial component of the lesions were assessed and the results were analyzed statistically using the nonparametric Mann-Whitney test. Epithelial expression of HLA-DR was observed in only five (20.8%) cases of AC (two low-grade and three high-grade lesions), with a very low median score of immunopositivity. By contrast, expression of HLA-DR was found in most LLSCC (97.9%), with a relatively high median score of positive cells. The score of HLA-DR-positive cells tended to be higher in tumors with regional lymph node metastasis, tumors in advanced clinical stages, and low-grade tumors, but the difference was not statistically significant (p > 0.05). In addition, there was a tendency towards higher expression of HLA-DR in highly/moderately keratinized tumors, and tumors with little/moderate nuclear pleomorphism (p > 0.05). The results suggest a potential role of HLA-DR in lip carcinogenesis, particularly in the development and progression of LLSCC. The expression of this protein can be related to the degree of cell differentiation in these tumors.

Regulation of Wnt/ß-catenin pathway may be related to Regγ in benign epithelial odontogenic lesions.

OBJECTIVES: The aim of this study was to analyze and compare the immunoexpressions of Regγ, Wnt-1, and ß-catenin in ameloblastomas, adenomatoid odontogenic tumors (AOTs), and odontogenic keratocysts (OKCs). STUDY DESIGN: Thirty solid ameloblastomas, 20 AOTs, and 30 OKCs were selected for analysis of the immunoexpression of Regγ, Wnt-1, and ß-catenin. Each case was semiquantitatively evaluated in the epithelial component and in their different cellular compartments (membrane, cytoplasm, and nucleus). RESULTS: Ameloblastomas displayed higher cytoplasmic and nuclear Regγ expression compared with AOTs and OKCs, as well as higher membrane and cytoplasmic Wnt-1 expression (P < .05). ß-catenin membrane expression was higher in OKCs compared with ameloblastomas and AOTs (P < .05). Nuclear ß-catenin expression was higher in ameloblastomas and AOTs than in OKCs (P < .05). Cytoplasmic and nuclear Regγ expression in AOTs were positively correlated with nuclear ß-catenin expression (P < .05). CONCLUSIONS: The marked expressions of Regγ, Wnt-1, and ß-catenin suggest the participation of these proteins in the pathogenesis of the studied lesions. The greater expressions of Regγ, Wnt-1, and nuclear ß-catenin in ameloblastomas may be related to their more aggressive behavior. Pro-tumor effects of nuclear ß-catenin may be counterbalanced by inhibitory pathways in AOTs, justifying their low aggressiveness.

Clinicopathological and immunohistochemical analysis of spindle cell squamous cell carcinoma of the tongue: a rare case.

Spindle cell squamous cell carcinoma of the tongue is a rare variant of squamous cell carcinoma. This paper reports the case of a spindle cell squamous cell carcinoma of the tongue, in a 64-year-old male patient, and presents a review of the etiopathogenesis, clinicopathological and immunohistochemical features and treatment of the malignancy. The patient presented for evaluation of a painful swelling on his tongue. Extraoral examination revealed palpable submandibular and superior cervical lymph nodes. Based on the presumptive diagnoses of squamous cell carcinoma or malignant salivary gland neoplasm, an incisional biopsy was performed. Histopathological analysis showed a proliferation of atypical spindle cells, exhibiting extensive pleomorphism. Tumor cells were positive for vimentin, P53 and alpha-smooth muscle actin, focally positive for epithelial membrane antigen and P63, and negative for pan-cytokeratin (AE1/AE3), CK7, CD138, CD34, CD56, and S-100. The positivity index for Ki-67 was approximately 40%. The diagnosis of spindle cell squamous cell carcinoma was established and the patient was referred to a head and neck surgery service. In the oral cavity, spindle cell squamous cell carcinoma of the tongue is an aggressive variant of squamous cell carcinoma, which usually presents as an exophytic mass located on the tongue of elderly males. Due to its distinct histopathological characteristics, immunohistochemistry is a valuable and helpful tool to establish the diagnosis of spindle cell squamous cell carcinoma of the tongue.

Twist and E-cadherin deregulation might predict poor prognosis in lower lip squamous cell carcinoma.

OBJECTIVE: The aim of this study was to evaluate the expression of Twist and E-cadherin in lower lip squamous cell carcinoma (LLSCC) and their association with clinicopathologic parameters. STUDY DESIGN: Fifty-nine cases of LLSCC were analyzed by applying immunohistochemistry techniques in a semiquantitative manner. The systems proposed by Bryne etal., Brandwein-Gensler etal., and Almangush etal. were applied for analysis of the histopathologic malignancy grading system. RESULTS: Higher E-cadherin expression (general and membrane) was observed in cases presenting with disease-free survival after 5years of follow-up (P < .05). Higher Twist expression was observed in lesions classified as being in advanced stages, displaying recurrence, and having a high degree of malignancy. A significant negative correlation was detected between cytoplasmic Twist expression and membrane E-cadherin expression (P = .028). A statistically significant relationship was detected between high total Twist expression in tumors classified as high risk by Brandwein-Gensler etal., and no significant difference was observed among total, membrane, and cytoplasmic E-cadherin expressions in LLSCC cases and the 3 applied grading systems (P > .05). CONCLUSIONS: The results of the present study suggest the potential involvement of Twist and E-cadherin in the modulation of events related to worse prognoses in LLSCC cases.

Assessment of CTNNB1 gene mutations and ß-catenin immunoexpression in salivary gland pleomorphic adenomas and adenoid cystic carcinomas.

ß-Catenin exerts multiple functions in several neoplasms, playing a major role in cell signaling and tumor progression. This study analyzed possible CTNNB1 mutations in salivary gland pleomorphic adenomas (PAs) and adenoid cystic carcinomas (ACCs), and determined possible differences in ß-catenin immunoexpression in relation to these mutations, as well as histopathological aspects of these tumors. Twenty-four PAs (15 cell-rich and 9 cell-poor tumors) and 24 ACCs (10 tubular, 8 cribriform, and 6 solid tumors) were selected for the analysis of ß-catenin distribution and cellular localization. Furthermore, ß-catenin expression was evaluated using the H-score scoring system. Mutations in CTNNB1 exon 3 were investigated by the single-strand conformational polymorphism test. Diffuse ß-catenin expression was more frequently observed in ACCs compared to PAs (P = 0.008). No significant difference in ß-catenin cellular localization was observed between these tumors (P = 0.098). Comparisons between PA and ACC cases revealed a higher median H-score in the latter (P = 0.036). Cell-rich PAs exhibited a trend for higher H-score than cell-poor tumors (P = 0.060), whereas lower H-scores were observed in cribriform ACCs when compared to tubular and solid ACCs (P = 0.042). Mutations in CTNNB1 were observed in 6 PAs and 7 ACCs, with no significant difference in H-scores for ß-catenin according to mutation status (P = 0.135). ß-Catenin is important in the pathogenesis of salivary gland PAs and ACCs. In addition, CTNNB1 exon 3 mutations do not seem to significantly influence ß-catenin cytoplasmic/membranous expression or nuclear translocation in these tumors.

Participation of hypoxia-inducible factor-1α and lymphangiogenesis in metastatic and non-metastatic lower lip squamous cell carcinoma.

This study evaluated the lymphatic density and HIF-1α immunoexpression in lower lip squamous cell carcinoma (LLSCC) and their correlation with clinicopathological (nodal metastasis, clinical stage, histological grade, recurrence and disease outcome) and survival parameters in 20 metastatic and 20 non-metastatic LLSCCs. Lymphatic density was established by counting microvessels (D2-40+) at the tumor core (intratumoral lymphatic density, ILD) and at the invasive front (peritumoral lymphatic density, PLD) and percentages of immunopositive cells for HIF-1α were established. No statistically significant differences in lymphatic densities in relation to clinicopathological parameters were observed (P > 0.05). All cases exhibited nuclear and cytoplasmic HIF-1α immunoexpression, with relatively high percentages of positivity, but this expression was not statistically different in relation to clinicopathological variables (P > 0.05). Positive correlations were observed between ILD and PLD (P = 0.002), and between nuclear HIF-1α immunoexpression at the tumor core and ILD (P = 0.001). The results suggest ILD and PLD are not directly related to the development of lymph node metastasis in LLSCC. The striking expression of HIF-1α suggests the involvement of this protein in the etiopathogenesis of LLSCCs, possibly stimulating lymphangiogenesis at the tumor core. However, this protein does not seem to exert a determining influence on the biological aggressiveness of these tumors.

Clinical and histopathological features of nasopalatine duct cyst: A 47-year retrospective study and review of current concepts.

PURPOSE: To evaluate the clinical and histopathological features of nasopalatine duct cysts (NDCs) stored in the archives of a referred Oral Pathology Service over a 47-year-period, and to review current concepts about these cysts. MATERIAL AND METHODS: All NDCs were reviewed, and clinical data were obtained from the patient records. Thirty cases were re-evaluated microscopically by 2 oral pathologists. RESULTS: Among 14,564 cases, 30 (0.20%) were NDCs. Fifteen (50.0%) of the patients were female, and the mean age was 42.7 years. The lesions measured on average 2.37 ± 1.69 cm. Histologically, stratified squamous epithelium, alone or in combination with other epithelia, was present in 13 (46.6%) cases. Goblet cells and subepithelial hyalinization were common. Fourteen (46.6%) cases exhibited a slight degree of inflammation. Nerves were observed in 15 (50%) cases and mucous glands in 7 (23.3%). Hyaline ring granulomas (which is described here for the first time in NDC) and cholesterol crystals were not common. CONCLUSION: Knowledge of clinical-histopathological aspects of NDCs provides more accurate data about their nature and behavior. Our results suggest that the predominant epithelial lining of these cystic lesions is exclusively stratified squamous epithelium or combined with another type. Vessels, nerves, mucous glands and inflammatory infiltrate are frequently observed.

Calcifying Odontogenic Cyst with Extensive Areas of Dentinoid: Uncommon Case Report and Update of Main Findings.

The calcifying odontogenic cyst (COC) is a benign odontogenic cyst that occurs in the gnathic bones. This cyst is part of a spectrum of lesions characterized by odontogenic epithelium containing "ghost cells," which may undergo calcification. Areas of an eosinophilic matrix material compatible dentinoid also may present adjacent to the epithelial component. However, these areas of dentinoid commonly do not appear so abundant in COCs. In this study, we report a case of intraosseous COC with extensive areas of dentinoid and perform an update regarding the clinical, radiographical, histopathological, and differential diagnosis, treatment, and prognosis of this cystic lesion.

Clinical and immunohistochemical study of melanotic neuroectodermal tumor of infancy in the maxilla.

Melanotic neuroectodermal tumor of infancy is a rare and fast-growing neoplasm. In this study, we describe the case of a 6-month-old female patient, who presented swelling in the anterior maxilla. Tomographic reconstruction showed an unilocular hypodense and expansive area associated with the upper right central primary incisor. The presumptive diagnoses were dentigerous cyst, adenomatoid odontogenic tumor, melanotic neuroectodermal tumor of infancy and rhabdomyosarcoma, and an incisional biopsy was performed. Microscopically, the lesion revealed a biphasic cell population, consisting of small, ovoid, neuroblastic-like cells and epithelioid cells containing melanin. Immunohistochemically, the melanocyte-like component was strongly and diffusely positive for HMB-45 and Melan-A, but weakly positive for S100. Based on these findings, definitive diagnosis of melanotic neuroectodermal tumor of infancy was established. Then, enucleation of the lesion was performed by careful curettage. After 2 year follow-up, no clinical or radiographical evidence of recurrence was verified. The present case highlights the importance of early diagnosis and therapeutic intervention at the appropriate time to achieve a favorable outcome for the patient.

Immunohistochemical analysis of SHH, SMO and GLI-1 proteins in epithelial odontogenic lesions

Abstract The present study analyzed the expression of proteins involved in the sonic hedgehog signaling pathway (SHH, SMO, and GLI-1) in benign epithelial odontogenic lesions (odontogenic keratocyst - OKC, ameloblastoma - AB, and adenomatoid odontogenic tumor - AOT) in order to identify the role of these proteins in the pathogenesis of these lesions. The sample consisted of 20 OKCs, 20 ABs, and 10 AOTs. The Kruskal-Wallis, Mann-Whitney U, and Spearman's (r) tests were used for statistical analysis, with the level of significance set at 5% (p < 0.05). The membrane/cytoplasmic expression of SHH was significantly higher in AB compared to AOT (p = 0.022) and OKC (p = 0.02). No differences were found in the membrane/cytoplasmic expression of SMO between the lesions studied. Regarding GLI-1, significant differences were observed at the nuclear level for AB and OKC compared to AOT (p < 0.0001). In addition, significant positive correlations were found between cytoplasmic and nuclear GLI-1 in AB (r = 0.482; p = 0.031) and OKC (r = 0.865; p < 0.0001), and between membrane/cytoplasmic SMO and cytoplasmic GLI-1 in AOT (r = 0.667; p = 0.035) and OKC (r = 0.535; p = 0.015). The results of this study confirm the participation of the sonic hedgehog signaling pathway in the pathogenesis of the lesions studied. Overexpression of SHH in ABs and nuclear expression of GLI-1 in ABs and OKCs indicate that these proteins contribute to the more aggressive behavior of these two lesions when compared to AOT.

Resumo O presente estudo analisou a expressão de proteínas envolvidas na via de sinalização Sonic Hedgehog (SHH, SMO e GLI-1) em lesões benignas do epitélio odontogênico de comportamento biológico distintos, tais como ceratocistos odontogênicos (CO), ameloblastomas (AMB) e tumores odontogênicos adenomatoides (TOA), com o intuito de identificar o papel destas proteínas na patogênese destas lesões. A amostra foi constituída de 20 CO, 20 AMB e 10 TOA, analisada pela técnica da imuno-histoquímica de forma semiquantitativa por compartimento celular, onde foi feita uma análise da membrana e citoplasma das células nas proteínas SHH e SMO, enquanto que para a proteína GLI-1, foi feita uma análise nuclear e/ou citoplasmática. Para análise estatística, foram utilizados os testes de Kruskal-Wallis (KW), Mann-Whitney (U) e Spearman (r), com o nível de significância estabelecido em 5% (p < 0,05). Ao analisar a proteína SHH, observou-se que o AMB demonstrou expressão membranar/citoplasmática significativamente maior em comparação ao TOA (p = 0,022) e CO (p = 0,020). Com relação à análise membranar/citoplasmática da SMO, não foram identificadas diferenças entre as lesões estudadas. Para a proteína GLI-1, foram constatadas diferenças estatisticamente significativas, em nível nuclear, para o AMB e CO em comparação ao TOA (p< 0,0001). Além disso, foram observadas correlações positivas com significância estatística entre GLI-1 citoplasmático e GLI-1 nuclear para o AMB (r = 0,482; p = 0,031) e CO (r = 0,865; p< 0,0001), e entre o SMO membranar/citoplasmático e o GLI-1 citoplasmático para o TOA (r = 0,667; p = 0,035) e o CO (r = 0,535; p = 0,015). Os resultados deste estudo confirmam a participação da via de sinalização Sonic Hedgehog na patogênese das lesões estudadas e, a superexpressão de SHH em AMBs e GLI-1 nuclear em AMBs e COs, indica que estas proteínas contribuem com o comportamento biológico mais agressivo destas duas lesões quando comparado ao TOA.