Aims
Ameloblastic carcinoma (AMECA) is an odontogenic malignancy that combines the histological features of ameloblastoma and cytological atypia. Because of its rarity, it poses difficulties in ...diagnosis. The aim of this study was to investigate the socio‐demographic data, histopathology, immunohistochemical features, treatment and outcomes of 17 cases.
Methods and results
Descriptive statistical analyses were used to portray the clinicopathological data collected, retrospectively. Log‐rank tests were performed to determine new prognostic factors. Lesions were immunostained for Ki67, p16, p53, and cytokeratins (CKs), and compared with solid/multicystic ameloblastomas (n = 15). AMECA was mostly diagnosed at a late stage, affecting the posterior mandible of male patients in their fifth decade of life. Recurrence was diagnosed in nearly 90% of treated patients, and metastasis occurred in four patients. The mean number of Ki67‐positive cells was 86.4 ± 66 per field. Tumours were focally positive for CK7, CK8, CK14, and CK18, and diffusely positive for CK19, p53, and p16. AMECA showed increased immunoexpression of CK18, CK19, p16, p53 and Ki67 as compared with benign cases.
Conclusions
Our study has contributed to the improved characterization of the epidemiology, prognostic markers, treatment options and outcomes of AMECA. Current criteria must be reviewed to simplify the diagnostic process for these neoplasms.
In this work, a computational scheme is proposed to identify the main combinations of handcrafted descriptors and deep-learned features capable of classifying histological images stained with ...hematoxylin and eosin. The handcrafted descriptors were those representatives of multiscale and multidimensional fractal techniques (fractal dimension, lacunarity and percolation) applied to quantify the histological images with the corresponding representations via explainable artificial intelligence (xAI) approaches. The deep-learned features were obtained from different convolutional neural networks (DenseNet-121, EfficientNet-b2, Inception-V3, ResNet-50 and VGG-19). The descriptors were investigated through different associations. The most relevant combinations, defined through a ranking algorithm, were analyzed via a heterogeneous ensemble of classifiers with the support vector machine, naive Bayes, random forest and K-nearest neighbors algorithms. The proposed scheme was applied to histological samples representative of breast cancer, colorectal cancer, oral dysplasia and liver tissue. The best results were accuracy rates of 94.83% to 100%, with the identification of pattern ensembles for classifying multiple histological images. The computational scheme indicated solutions exploring a reduced number of features (a maximum of 25 descriptors) and with better performance values than those observed in the literature. The presented information in this study is useful to complement and improve the development of computer-aided diagnosis focused on histological images.
In this paper, we propose an approach based on ensemble learning to classify histology tissues stained with hematoxylin and eosin. The proposal was applied to representative images of colorectal ...cancer, oral epithelial dysplasia, non-Hodgkin’s lymphoma, and liver tissues (the classification of gender and age from liver tissue samples). The ensemble learning considered multiple combinations of techniques that are commonly used to develop computer-aided diagnosis methods in medical imaging. The feature extraction was defined with different descriptors, exploring the deep learning and handcrafted methods. The deep-learned features were obtained using five different convolutional neural network architectures. The handcrafted features were representatives of fractal techniques (multidimensional and multiscale approaches), Haralick descriptors, and local binary patterns. A two-stage feature selection process (ranking with metaheuristics) was defined to obtain the main combinations of descriptors and, consequently, techniques. Each combination was tested through a rigorous ensemble process, exploring heterogeneous classifiers, such as Random Forest, Support Vector Machine, K-Nearest Neighbors, Logistic Regression, and Naive Bayes. The ensemble learning presented here provided accuracy rates from 90.72% to 100.00% and offered relevant information about the combinations of techniques in multiple histological images and the main features present in the top-performing solutions, using smaller sets of descriptors (limited to a maximum of 53), which involved each ensemble process and solutions that have not yet been explored. The developed methodology, i.e., making the knowledge of each ensemble learning comprehensible to specialists, complements the main contributions of this study to supporting the development of computer-aided diagnosis systems for histological images.
Aims
Studies on epigenetics in oral squamous cell carcinoma (OSCC) are rare. Histone modifications comprise epigenetic mechanisms that perform a key role in gene transcription and may regulate tumour ...development. Thus, the aim of this study was to determine whether two post‐translational histone modifications, i.e. phosphorylation of serine 10 in histone H3 and acetylation of lysine 12 in histone H4, have prognostic value for OSCC patients.
Methods and results
Paraffin‐embedded tissue samples of 90 patients diagnosed with OSCC were obtained and subjected to immunohistochemical staining with antibodies against histone H3 with phosphorylation of serine 10 (H3S10ph) and histone H4 with acetylation of lysine 12 (H4K12ac). The associations of H3S10ph and H4K12ac expression levels with clinicopathological factors were determined. Five‐year survival analysis and univariate and multivariate analyses were also performed. Both H3S10ph and H4K12ac were expressed in the nuclei of tumour cells. A low median of H3S10ph expression was significantly associated with cervical lymph node metastasis. Tumours with high H4K12ac expression were significantly associated with gender, alcohol consumption, and cervical lymph node metastasis. H4K12ac was also shown to have independent prognostic value in the multivariate analysis. Tumours with high H3S10ph expression, size >40 mm, an advanced stage and the presence of cervical lymph node metastases were associated with a better 5‐year survival rate. Tumours with low H4K12ac expression, size >40 mm, an advanced stage and cervical lymph node metastasis were associated with a better 5‐year survival rate.
Conclusions
These findings suggest that H3S10ph, and mainly H4K12ac, may play a role in OSCC progression and the occurrence of cervical lymph node metastasis. Also, the expression level of H4K12ac could be an independent prognostic factor for OSCC patients.
Oral epithelial dysplasia is a potentially malignant lesion that presents challenges for diagnosis. The use of digital systems in histological analysis can aid specialists to obtain data that allows ...a robust and fast grading process, but there are few methods in the literature proposing a grading system for this lesion. This study presents a method for oral epithelial dysplasia grading in histopathological images combining deep features and a polynomial classifier. The ResNet50 and AlexNet models were trained with the images and information was extracted from the convolutional layers, exploring convolutional neural networks via transfer learning. Then, the ReliefF algorithm was used to rank and select the most relevant features, which were given as an input to the polynomial classifier. The methodology was employed in a dataset with 296 regions of mice tongue images. The results were compared with the gold standard and other algorithms present in the literature. The classification stage presented AUC values ranging from 0.9663 to 0.9800. When compared to other algorithms present in the literature, our method provided relevant results regarding accuracy and AUC values. The proposed approach presented relevant results and can be used as a tool to aid pathologists in grading oral dysplastic lesions.
To evaluate the intraosseous biocompatibility of AH Plus, EndoREZ, and Epiphany root canal sealers as recommended by the Technical Report #9 of the Fédération Dentaire Internationale (FDI). Thirty ...guinea pigs, 10 for each material, divided into experimental periods of 4 and 12 weeks, received one implant on each side of the lower jaw symphysis. At the end of the observation periods, the animals were killed and the specimens prepared for routine histological examination. After analyzing both periods, the inflammatory tissue reaction to EndoREZ was considered severe. In the AH Plus group, the reaction changed from severe to moderate, while it was observed biological compatibility to Epiphany with bone formation and none to slight inflammatory reaction. It was concluded that Epiphany root canal sealer was the only material that presented intraosseous biocompatibility within the two analyzed periods.
Information on the biology of metastasis development in salivary gland tumors is scarce. Since angiogenesis seems associated with this phenomenon in other tumors, we sought to compare salivary gland ...tumors with diverse metastatic behavior in order to improve the knowledge and management of these lesions.
Samples from the most important salivary gland tumors were segregated according to its metastatic behavior and submitted to routine immunohistochemistry to identify vessels positive for CD105 expression. Frequency of positive cases and intratumoral microvessel density (IMD) was compared among the group of lesions.
CD105 positive vessels were absent in normal salivary gland tissue, were rare in pleomorphic adenomas and adenoid cystic carcinomas (ACC), more common in polymorphous low-grade adenocarcinomas and highest in mucoepidermoid carcinomas. Only ACC with such feature were metastatic. IMD was higher in malignant rather than benign tumors.
Immunostaining of CD105 in salivary gland tumors implies participation of angiogenesis in the development of malignant lesions, as well as some role for myoepithelial cells in the control of new vessel formation. In addition, suggest that ACC with positive CD105 vessels are at higher risk for metastasis.
Aims
Metallothioneins (MTs) are proteins associated with the carcinogenesis and prognosis of various tumours. Previous studies have shown their potential as biomarkers in oral squamous cell carcinoma ...(OSCC). Aiming to understand more clearly the function of MTs in OSCC we evaluated, for the first time, the gene expression profile of MTs in this neoplasm.
Materials and results
Tissue samples from 35 cases of tongue and/or floor of mouth OSCC, paired with their corresponding non‐neoplastic oral mucosa (NNOM), were retrieved (2007–09). All tissues were analysed for the following genes using TaqMan® reverse transcription–quantitative polymerase chain reaction (RT–qPCR) assays: MT1A, MT1B, MT1E, MT1F, MT1G, MT1H, MT1X, MT2A, MT3 and MT4. The expression of MT1B and MT1H was seldom detected in both OSCC and NNOM. A significant loss of MT1A, MT1X, MT3 and MT4 expression and gain of MT1F expression was observed in OSCC, compared to NNOM. Cases with MT1G down‐regulation exhibited the worst prognoses. The up‐regulation of MT1X was restricted to non‐metastatic cases, whereas up‐regulation of MT3 was related to cases with lymph node metastasis.
Conclusions
Metallothionein mRNA expression is altered significantly in oral squamous cell carcinomas. The expression of MT1G, MT1X and MT3 may aid in the prognostic discrimination of OSCC cases.
Galectin-3 is a β-galactoside-binding lectin implicated in the fine-tuning of innate immunity. Rhodococcus equi, a facultative intracellular bacterium of macrophages, causes severe granulomatous ...bronchopneumonia in young horses and immunocompromised humans. The aim of this study is to investigate the role of galectin-3 in the innate resistance mechanism against R. equi infection. The bacterial challenge of galectin-3-deficient mice (gal3⁻/⁻) and their wild-type counterpart (gal3⁺/⁺) revealed that the LD₅₀ for the gal3⁻/⁻ mice was about seven times higher than that for the gal3⁺/⁺ mice. When challenged with a sublethal dose, gal3⁻/⁻ mice showed lower bacteria counts and higher production of IL-12 and IFN-γ production, besides exhibiting a delayed although increased inflammatory reaction. Gal3⁻/⁻ macrophages exhibited a decreased frequency of bacterial replication and survival, and higher transcript levels of IL-1β, IL-6, IL-10, TLR2 and MyD88. R. equi-infected gal3⁺/⁺ macrophages showed decreased expression of TLR2, whereas R. equi-infected gal3⁻/⁻ macrophages showed enhanced expression of this receptor. Furthermore, galectin-3 deficiency in macrophages may be responsible for the higher IL-1β serum levels detected in infected gal3⁻/⁻ mice. Therefore galectin-3 may exert a regulatory role in innate immunity by diminishing IL-1β production and thus affecting resistance to R. equi infection.
J Oral Pathol Med (2012) 41: 389–393
Although molecular alterations are reported in different types of odontogenic tumours, their pathogenesis remains to be established. Loss of heterozygosity (LOH) ...studies allow the identification of minimal regions of deletions of known or putative tumour suppressor genes, the losses of which may promote neoplastic growth. The purpose of this study was to investigate LOH in a set of odontogenic mixed tumours. Tumour suppressor gene loci on 3p, 9p, 11p, 11q and 17p chromosomes were analysed in five samples of ameloblastic fibroma (AF), three samples of ameloblastic fibro‐odontoma (AFO) and three samples of ameloblastic fibrosarcoma (AFS). The most frequently lost genetic loci were p53 (17p13, 62%) and CHRNB1 (17p13, 55%). LOH at the chromosome regions 3p24.3, 9p22 and 9p22‐p21 was identified only in AFS. No sample showed LOH at the chromosomal loci 3p21.2 and 11q13.4. For the region 9p22–p13, LOH occurred in one sample of AFO. The fractional allelic loss (FAL) was calculated for each sample. The mean FAL of the benign lesions (i.e. AF and AFO) was 22%, whereas the mean FAL of the malignant lesions (i.e. AFS) was 74.6%. In conclusion, our results show a higher FAL in AFS compared to its benign counterparts and reveal a different pattern of LOH of tumour suppressor genes in AFS, which may regulate changes in tumour behaviour.
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