Hybrid odontogenic lesions: A systematic review of 203 cases reported in the literature.

BACKGROUND: Hybrid odontogenic lesions combine histopathological characteristics of two or more odontogenic cysts and/or tumours. The aim of this study was to evaluate the available data on hybrid odontogenic lesions (HOL) and to analyse their epidemiological/clinical features and biological behaviour. METHODS: An electronic search was done in January 2021 using multiple databases. Eligibility criteria encompassed publications with sufficient clinical and histological information to confirm the tumours' diagnoses. RESULTS: A total of 147 articles were included in this study, comprising 203 cases. Calcifying odontogenic cyst associated with odontoma (COC/OD) (37/18.2%) was the most common HOL. Females were more affected with a mean age of 24.9 years. Lesions presented as asymptomatic swellings, with a mean evolution time of 8.2 months (0.3-96), and mean tumour size of 4.8 cm (0.3-7). Radiographic aspects frequently showed radiolucent (139/68.4%) and unilocular (52/25.6%) images with well-defined limits (48/23.6%). The lesions mostly affected mandibular pre-molars (69/34%) and mandibular molars (69/34%) regions. Enucleation (89/43.8%) and surgical excision (59/29%) were the most common treatment modalities. The mean follow-up time was 33.8 months (0.5-216 months) and recurrences were observed in four cases (1.9%), all of which were central odontogenic fibroma associated with central giant cell granuloma (COF/CGCG). CONCLUSION: COC/OD is the most common HOL and recurrence is a rare event, being usually associated with the diagnosis of COF/CGCG.

Mebendazole disrupts stromal desmoplasia and tumorigenesis in two models of pancreatic cancer.

The five-year survival rate for metastatic pancreatic cancer is currently only 3%, which increases to 13% with local invasion only and to 39% with localized disease at diagnosis. Here we evaluated repurposed mebendazole, an approved anthelminthic drug, to determine how mebendazole might work at the different stages of pancreatic cancer formation and progression. We asked if mebendazole could prevent initiation of pancreatic intraepithelial neoplasia precursor lesions, interfere with stromal desmoplasia, or suppress tumor growth and liver metastasis. In both the Kras LSL.G12D/+; Pdx1-Cre (KC) mouse model of caerulein-induced inflammatory pancreatitis and the Kras LSL.G12D/+; Tp53 R172H/+; Pdx1-Cre (KPC) mouse model of advanced pancreatic cancer, mebendazole significantly reduced pancreas weight, dysplasia and intraepithelial neoplasia formation, compared to controls. Mebendazole significantly reduced trichrome-positive fibrotic connective tissue and α-SMA-positive activated pancreatic stellate cells that heralds fibrogenesis. In the aggressive KPC model, mebendazole significantly suppressed pancreatic tumor growth, both as an early and late intervention. Mebendazole reduced the overall incidence of pancreatic cancer and severity of liver metastasis in KPC mice. Using early models of pancreatic cancer, treatment with mebendazole resulted in less inflammation, decreased dysplasia, with the later stage model additionally showing a decreased tumor burden, less advanced tumors, and a reduction of metastasis. We conclude that mebendazole should be investigated further as a component of adjuvant therapy to slow progression and prevent metastasis, and well as for primary prevention in the highest risk patients.

Odontogenic Keratocyst in a 9-Month-Old Patient: A Case Report.

Odontogenic Keratocyst (OKC) is a benign, intraosseous, odontogenic cyst which originates from the basal cells of overlying epithelium or from the dental lamina remnants. Clinically, they are presented as asymptomatic swellings, although can sometimes be associated with pain. Growth of an OKC leads to expansion and destruction of bone as it infiltrates the tissue around it. It is commonly seen in males between the second and fourth decades of life. The aim of this study is to report on the clinicopathological characteristics of an odontogenic keratocyst in a 9-month-old female patient and posterior rehabilitation with a removable maxillary expander.

Significance of P16INK4A Expression and PTEN Loss of Heterozygosity in Human Papilloma Virus-related Oral Squamous Cell Carcinoma.

BACKGROUND/AIM: p16 and PTEN are tumor suppressor genes. Loss of these molecules in oral squamous cell carcinoma (OSCC) has been studied worldwide. In this study, we explored whether p16 cooperates with inactive PTEN during the pathogenesis of OSCC, especially in regard to tumor aggressiveness and proliferation. MATERIALS AND METHODS: Immunocytochemistry and western blot analysis were used to examine the levels of p16 and PTEN. Sequencing analysis was performed to identify mutations in the PTEN gene and HPV infection. Fluorescence in situ hybridization was used to examine the presence of the PTEN locus. RESULTS: PTEN analysis showed high positivity in T4 samples. HPV-positive tumors correlated with tabagism, tumor size 3 and 4, disease stages 3 and 4, presence of lymph node metastasis (N1) and poor differentiation. Immunoexpression of p16 was strongly correlated with the presence of HPV. CONCLUSION: PTEN demonstrated a higher reactivity in advanced disease stages and p16 was strongly associated with HPV. Viral presence decreases tumor aggressiveness. Patients with advanced stage lesions demonstrated lower survival rate.

Whole-Genome Sequencing of an Unusual Human Papillomavirus (HPV71) from Latin America (Brazil).

We report the complete genome sequencing of human papillomavirus 71 from Latin America (Brazil).

Nuclear factor κB and cyclooxygenase-2 immunoexpression in oral dysplasia and oral squamous cell carcinoma.

Oral leukoplakia is the main potentially malignant oral lesion, and oral squamous cell carcinoma accounts for more than 95% of all malignant neoplasms in the oral cavity. Therefore, the aim of this study was to verify the immunoexpression of nuclear factor κB (NF-κB) and cyclooxygenase-2 (COX-2) proteins in dysplastic oral lesions and oral squamous cell carcinoma. Immunohistochemical reactions were performed on 6 inflammatory fibrous hyperplasia, 28 oral leukoplakia, and 15 oral squamous cell carcinoma paraffin-embedded samples. Immunoperoxidase reaction for NF-κB and COX-2 was applied on the specimens, and the positivity of the reactions was calculated for 1000 epithelial cells. Using the analysis of variance and the Tukey post hoc statistical analyses, a significantly increased immunoexpression for NF-κB was observed when oral squamous cell carcinoma samples were compared with the other groups studied. However, using the Kruskal-Wallis and the Dunn post hoc tests, a statistically significant result for COX-2 expression was obtained only when the moderate dysplasia group was compared with the inflammatory fibrous hyperplasia group. Nuclear factor κB may participate in the malignant phenotype acquisition process of the oral squamous cell carcinoma in its late stages, whereas COX-2 may be involved in the early stages of oral carcinogenesis process.