Intraductal Papillary Mucinous Neoplasm: New Insights Into Its Origin and Nomenclatures.

Background: Mucinous cells can be detected sporadically or may constitute the primary tumor component in salivary gland tumors, as observed in the intraductal papillary mucinous neoplasm (IPMN). This low-grade tumor is composed of mucinous columnar cells organized into papillary cystic structures. The present study aimed to compare the mucous cells in IPMN with mucous cells present in mucoepidermoid carcinoma (MEC) and papillary cystadenoma (PC).

Adenomatoid odontogenic tumor: Features of ameloblastic-like epithelial cells differentiation, secretion, and the nature of tumor cells products.

Background: This study aimed to investigate the differentiation of ameloblastic-like cells and the nature of the secreted eosinophilic materials in adenomatoid odontogenic tumors.

Methods: We studied histological and immunohistochemical characteristics of 20 cases using: cytokeratins 14 and 19, amelogenin, collagen I, laminin, vimentin, and CD34.

Results: Rosette cells differentiated into ameloblastic-like cells positioned face-to-face, displaying collagen I-positive material between them.

Estrogen Receptor, Progesterone Receptor, and HER-2 Expression in Recurrent Pleomorphic Adenoma.

Pleomorphic adenoma (PA) is the most common salivary gland neoplasm and, although mostly benign, recurrences, being called recurrent pleomorphic adenoma (RPA) and malignant transformation to carcinoma ex pleomorphic adenoma (CXPA), do occur. Recently, attention has been focused on molecular targeted cancer therapy in various tumors, including salivary gland tumors. The aim of this study was to investigate the role of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2) in PA, RPA, and CXPA.

The Challenging Diagnosis of Primordial Odontogenic Tumor.

Primordial odontogenic tumor (POT) is a benign mixed odontogenic tumor comprised of a loose connective tissue with a similar morphology with dental papilla and exhibiting in its periphery the presence of a columnar epithelium. POT occurs in young patients and typically is associated with an unerupted tooth, with the mandible being the main anatomic site of occurrence. The present manuscript is aimed at describing a new case of POT and reviewing the main biologic findings related to this odontogenic tumor.

Can non-collagenous proteins be employed for the differential diagnosis among fibrous dysplasia, cemento-osseous dysplasia and cemento-ossifying fibroma?

Differential diagnosis among fibrous dysplasias, cemento-ossifying fibromas and cemento-osseous dysplasias is difficult, since there is considerable overlap of histologic features, but also extremely important, since they differ greatly in etiology, clinical behaviour, prognosis and terapeuthic approach. There is no data about the use of immunohistochemistry, a viable and accessible technique, for this purpose. The objective of this study was to investigate, comparatively, the immunohistochemical expression of major non-collagenous proteins (osteonectin [ON], osteopontin [OP], bone sialoprotein [BSP] and osteocalcin [OC]) of mineralized tissue extracellular matrix in 22 cases of fibrous dysplasias, 16 of cemento-ossifying fibromas and 16 of cemento-osseous dysplasias.

Benign odontogenic ghost cell lesions revisited and new considerations on dysplastic dentin.

Objectives: This study aimed to revisit benign odontogenic ghost cell lesions (BOGCL) by hematoxylin and eosin staining and immunohistochemistry.

Materials And Methods: Thirty cases of calcifying odontogenic cyst (COC) and 6 cases of dentinogenic ghost cell tumor (DGCT) were selected for histopathological and immunohistochemical analysis. Sections stained for cytokeratin (K) 14, K-19, amelogenin, collagen type 1 (COL-1), and dentin matrix acidic phosphoprotein 1 (DMP-1) were evaluated using qualitative analysis.

Role of apoptotic, autophagic and senescence pathways in minor salivary gland adenoid cystic carcinoma.

Background: Adenoid cystic carcinoma (ACC) is a salivary gland malignancy with poor long-term survival, which warrants studies aimed at clarifying the pathogenesis of this disease in order to widen the scope of therapeutic options currently available. Alterations in regulatory mechanisms relating to vascular support, cell death and autophagy are important pathways for tumor growth in cancer. Thus, the present study aimed to access vascular supply, apoptosis, autophagy and cell senescence in ACC of minor salivary glands.

Comparison of p63/p40 Expression With Myoepithelial Markers in Minor Salivary Gland Tumors.

The present study aimed to compare the expression of p63/p40 with smooth muscle actin (SMA) and vimentin (VIM) by myoepithelial cells in minor salivary gland tumors. Fifty-two formalin-fixed paraffin-embedded samples of minor salivary gland tumors derived from intercalated duct (pleomorphic adenoma [PA], adenoid cystic carcinoma [ACC], epithelial-myoepithelial carcinoma [EMC], polymorphous adenocarcinoma [PAC], and secretory carcinoma [SC]) and 3 samples of minor salivary gland tumors derived from excretory duct (mucoepidermoid carcinoma [MEC]) were evaluated by means of immunohistochemistry. The data were analyzed qualitatively.

Microvessel density and cell proliferation in juvenile ossifying fibroma: A comparative study with central ossifying fibroma.

Considered as an aggressive counterpart of central ossifying fibroma (OF), juvenile ossifying fibroma (JOF) is a benign fibro-osseous neoplasm characterized by an unpredictable destructive behavior, elevated morbidity, mutilating treatment and high potential for local recurrences. The aim of this study is to compare the analysis for cell proliferation and vascular markers between JOF and OF. Cell proliferation index was measured by Ki-67 and Mcm-2 expression and microvessel density (MVD) was obtained by the immunoexpression of CD34/CD105.

Effect of epithelial growth factor on matrix metalloproteinase-2 and E-cadherin/β-catenin expression in an model of tumorigenesis.

The aim of the present study was to analyze the effect of various doses of epidermal growth factor (EGF; 5 and 10 ng/ml) on matrix metalloproteinase-2 (MMP-2) secretion and E-cadherin/β-catenin expression by co-cultured cells that mimic an carcinoma ex-pleomorphic adenoma, where benign myoepithelial cells from a pleomorphic adenoma surround malignant epithelial cells. EGF was supplemented in various doses and the effects were evaluated following four days of cell culture. ELISA was performed to determine MMP-2 secretion levels.

Factors that may influence polymorphous low-grade adenocarcinoma growth.

There is mounting evidence on the importance of some biological processes in tumor growth, such as vascular supply, apoptosis, autophagy, and senescence. We have investigated these processes in polymorphous low-grade adenocarcinoma (PLGA), in an attempt to identify those that are relevant for this particular lesion. We analyzed 31 cases of PLGA using immunohistochemistry to antibodies against CD34 and CD105 to detect blood vessels; against D2-40 to detect lymphatic vessels; against Bax, Bcl-2, and survivin to explore cell apoptosis; and against Beclin and LCB3 to investigate autophagy and against p21 and p16 to assess senescence.

Mammaglobin and DOG-1 expression in polymorphous low-grade adenocarcinoma: an appraisal of its origin and morphology.

Background: Polymorphous low-grade adenocarcinoma (PLGA) remains a diagnostic challenge for most pathologists due to its large spectrum of histological patterns. In this study, the expression of two new markers recently described for salivary gland tumors was studied in PLGA.

Methods: The morphology of 33 cases of PLGA was carefully evaluated using hematoxylin-and-eosin-stained sections and confirmed by immunohistochemistry for cytokeratin 7, vimentin, and S-100.

Dysregulation of the Rb pathway in recurrent pleomorphic adenoma of the salivary glands.

Pleomorphic adenoma (PA) is the most common salivary gland neoplasm, and while mostly benign, recurrences (RPA) and malignant transformation to carcinoma ex-PA (CXPA) do occur. Cell cycle proteins important in its tumorigenesis have been studied as markers for PA with a high risk of RPA or CXPA. The aim of the present study was to investigate cell cycle markers p-16, cyclin D1, CDK4, E2F, and retinoblastoma (Rb) in this context.

How do benign myoepithelial cells from in situ areas of carcinoma ex-pleomorphic adenoma favor tumor progression?

In this brief commentary, we have shown how the benign myoepithelial cells from in situ areas of carcinoma ex-pleomorphic adenoma from salivary gland can favor tumor progression, not only dying by autophagy/senescence phenomena, disrupting the physical barrier, but also providing fuel for tumor progression.

Cellular senescence and autophagy of myoepithelial cells are involved in the progression of in situ areas of carcinoma ex-pleomorphic adenoma to invasive carcinoma. An in vitro model.

During tumor invasion, benign myoepithelial cells of carcinoma ex-pleomorphic adenoma (CXPA) surround malignant epithelial cells and disappear. The mechanisms involved in the death and disappearance of these myoepithelial cells were investigated via analysis of the expression of regulatory proteins for apoptosis, autophagy and cellular senescence in an in situ in vitro model. Protein expression relating to apoptosis (Bax, Bcl-2, Survivin), autophagy (Beclin-1, LC3B) and cellular senescence (p21, p16) was evaluated using indirect immunofluorescence.

Myoepithelial cells from pleomorphic adenoma are not influenced by tumor conditioned media from breast ductal adenocarcinoma and melanoma cells: An study.

Myoepithelial cells have been implicated in the regulation of the transition from to invasive neoplasia in salivary gland tumors. Considering the importance of the microenvironment of the tumor, the present study therefore analyzed the morphological and phenotypic changes undergone by benign myoepithelial cells from pleomorphic adenoma (PA) stimulated by tumor-conditioned medium. The benign myoepithelial cells were obtained from PA and were cultured with fibronectin extracellular matrix protein, supplemented with tumor-conditioned medium, which was harvested from breast ductal adenocarcinoma AU-565 and melanoma Hs 852.

The EGF signaling pathway influences cell migration and the secretion of metalloproteinases by myoepithelial cells in pleomorphic adenoma.

During tumor development, benign neoplastic cells are influenced by the expression of cytokines, growth factors, and proteases present in the tumor microenvironment. Epidermal growth factor (EGF) is the most studied growth factor and is considered important for cell proliferation and migration. Metalloproteinases (MMPs) are also involved in tumor progression.

Tooth alterations in areas of bisphosphonate-induced osteonecrosis.

Objective: Osteonecrosis of the jaw is a potential side effect when using bisphosphonates. Most studies on the effects of bisphosphonates on teeth have been conducted in vitro or in animal models of tooth development. Therefore, the aim of this study was to describe alterations found in human teeth extracted from areas of bisphosphonate-induced osteonecrosis.

Brazilian orthodontists and the legal issues involving their professional activity: A legal and behavioral proposal.

Objective: The aim of this study was to review the use of orthodontic records (OTR's) by Brazilian orthodontists and propose a behavioral approach from a legal point of view, drawing on their interpersonal relationship with their patients.

Methods: A statistical cross-analysis was performed to compare five groups. A sixth group was created comprising the intersection of the responses provided by the five aforementioned groups.

Neutrophils in oral paracoccidioidomycosis and the involvement of Nrf2.

Neutrophils have been implicated in granuloma formation in several infectious diseases, in addition to their main phagocytic and pathogen destruction role. It has been demonstrated that Nrf2 regulates antioxidant protection in neutrophils, attenuating inflammation without compromising the hosts bacterial defense. In this study, we analyzed the presence of neutrophils in Paracoccidioides brasiliensis mycosis (PCM), as well as the immunoexpression of Nrf2.

Expression of peroxiredoxins I and IV in multiple myeloma: association with immunoglobulin accumulation.

B cell malignancies are classified according to the postulated differentiation stage of the originating cell. During differentiation, structural and molecular changes occur to support massive processing of immunoglobulin in the endoplasmic reticulum (ER) of plasma cells at the final stage. When overloaded, the ER generates unfolded proteins and hydrogen peroxide (H2O2), which may cause cell death.

Polymorphous low-grade adenocarcinoma: an analysis of epidemiological studies and hints for pathologists.

Background: This study is an analysis of the prevalence of polymorphous low grade adenocarcinoma (PLGA) in epidemiological surveys of salivary tumors published in the English language from 1992 to 2012.

Methods: These surveys included studies from different researchers, countries and continents. The 57 surveys for which it was possible to calculate the percentage of PLGAs among all malignant minor salivary gland tumors (MMSGT) were included in this review.

In vitro cytokine expression in in situ-like areas of malignant neoplasia.

Objectives: The myoepithelial cells exert important effects regulating the transition of an in situ to an invasive carcinoma. This cell has been associated with a tumour suppressor phenotype due to its ability to inhibit tumour growth as well as its immunomodulatory role in cancer behaviour.

Design: In order to correlate the cancer cell growth and the role of cytokines in regulating the neoplastic process, we have attempted to simulate an in vitro model of tumorigenesis, which mimics a situation where in situ neoplastic cells of carcinoma are surrounded by benign myoepithelial cells from pleomorphic adenoma.

Trabecular juvenile ossifying fibroma with aneurysmal bone cyst: a rare presentation.

Juvenile ossifying fibroma is an uncommon, benign, bone-forming neoplasm that is distinguished from other fibro-osseous lesions primarily by its age of onset, clinical presentation, and potential behavior. It mainly occurs in juveniles and has a slight male predilection and more aggressive behavior than a common ossifying fibroma. There are 2 distinct histopathological variants of this lesion: (1) psammomatoid pattern and (2) trabecular pattern.