Manuela Torres Andion Vidal

Distribution of mast cells in benign odontogenic tumors.

The aim of this study was to investigate the presence of mast cells in a series of odontogenic tumors. Forty-five cases of odontogenic tumors were investigated using immunohistochemistry for mast cell triptase, and differences between groups were statistically evaluated. Mast cells were present in 96% of odontogenic tumors. Mast cells present in solid ameloblastoma were observed in the tumor stroma surrounding more solid and follicular epithelial islands, with or without squamous metaplasia. The odontogenic mixoma showed few mast cells. In odontogenic tumors with a cystic structure, the mast cells were distributed throughout all areas of the lesions, mainly in keratocystic odontogenic tumor. In addition, the total density of mast cells between all odontogenic tumors showed no significant difference (p > 0.05). A greater mast cells distribution was found in keratocystic odontogenic tumor in relation to adenomatoid odontogenic tumor (p < 0.01), and when the unicystic ameloblastoma and keratocistic odontogenic tumor were compared to the odontogenic myxoma (p < 0.05). Syndrome keratocystic odontogenic tumor showed a higher mean of mast cells when compared with the other tumors of the sample. Mast cells values presented by syndrome keratocystic odontogenic tumor were significantly greater than those of the sporadic keratocystic odontogenic tumor that were not associated with the syndrome (p = 0.03). Mast cells are probably one of the major components of the stromal scaffold in odontogenic tumors. We found significant differences of mast cells between syndrome nonsyndrome keratocystic odontogenic tumors, although their distribution did not seem to have any influence on the biologic behavior of benign odontogenic tumors.

Density of mast cells and microvessels in minor salivary gland tumors

The aim of this study was to investigate the density of mast cells and microvessels in minor salivary gland tumors. Forty-one cases of minor salivary gland tumors (pleomorphic adenoma, n = 10; adenoid cystic carcinoma, n = 11; mucoepidermoid carcinoma, n = 10; and polymorphous low-grade adenocarcinoma) were investigated using immunohistochemistry for mast cell tryptase and von-Willebrand factor. Density of mast cells was higher in mucoepidermoid carcinoma; however, no differences in the number of these cells were observed between the different types of tumors (p > 0.05). The number of mast cells was higher in periparenchymal areas in all tumors, but the difference was not significant (p > 0.05). Mucoepidermoid carcinoma showed the largest number of periparenchymal mast cells, whereas pleomorphic adenomas showed the smallest number of intraparenchymal mast cells (p > 0.05). The highest microvessel density was observed in mucoepidermoid carcinomas, being this difference statistically significant when mucoepidermoid carcinoma was compared to pleomorphic adenoma (p = 0.0034) and polymorphous low-grade adenocarcinoma (p = 0.004). Microvessel density was significantly higher in adenoid cystic carcinoma when compared to pleomorphic adenoma (p = 0.0406) and polymorphous low-grade adenocarcinoma (p = 0.0123). Comparison of mast cells and microvessel densities showed no significant difference between tumors. A quantitative difference in mast cells and microvessels was observed, particularly in mucoepidermoid carcinoma, a finding supporting the aggressive behavior of malignant salivary gland tumors without myoepithelial differentiation. Further studies are needed to determine the role of mast cells in angiogenesis, as well as in the development and biological behavior of these tumors.

Novel piplartine-containing ruthenium complexes: synthesis, cell growth inhibition, apoptosis induction and ROS production on HCT116 cells

Piplartine (piperlongumine) is a plant-derived molecule that has been receiving intense interest due to its anticancer characteristics that target the oxidative stress. In the present paper, two novel piplartine-containing ruthenium complexes [Ru(piplartine)(dppf)(bipy)](PF6)2 (1) and [Ru(piplartine)(dppb)(bipy)](PF6)2 (2) were synthesized and investigated for their cellular and molecular responses on cancer cell lines. We found that both complexes are more potent than metal-free piplartine in a panel of cancer cell lines on monolayer cultures, as well in 3D model of cancer multicellular spheroids formed from human colon carcinoma HCT116 cells. Mechanistic studies uncovered that the complexes reduced the cell growth and caused phosphatidylserine externalization, internucleosomal DNA fragmentation, caspase-3 activation and loss of the mitochondrial transmembrane potential on HCT116 cells. Moreover, the pre-treatment with Z-VAD(OMe)-FMK, a pan-caspase inhibitor, reduced the complexes-induced apoptosis, indicating cell death by apoptosis through caspase-dependent and mitochondrial intrinsic pathways. Treatment with the complexes also caused a marked increase in the production of reactive oxygen species (ROS), including hydrogen peroxide, superoxide anion and nitric oxide, and decreased reduced glutathione levels. Application of N-acetyl-cysteine, an antioxidant, reduced the ROS levels and apoptosis induced by the complexes, indicating activation of ROS-mediated apoptosis pathway. RNA transcripts of several genes, including gene related to the cell cycle, apoptosis and oxidative stress, were regulated under treatment. However, the complexes failed to induce DNA intercalation. In conclusion, the complexes are more potent than piplartine against different cancer cell lines and are able to induce caspase-dependent and mitochondrial intrinsic apoptosis on HCT116 cells by ROS-mediated pathway.

Accessory mental foramen: A rare anatomical variation detected by cone-beam computed tomography

The mental foramen is a bilateral opening in the vestibular portion of the mandible through which nerve endings, such as the mental nerve, emerge. In general, the mental foramen is located between the lower premolars. This region is a common area for the placement of dental implants. It is very important to identify anatomical variations in presurgical imaging exams since damage to neurovascular bundles may have a direct influence on treatment success. In the hemimandible, the mental foramen normally appears as a single structure, but there are some rare reports on the presence and number of anatomical variations; these variations may include accessory foramina. The present report describes the presence of accessory mental foramina in the right mandible, as detected by cone-beam computed tomography before dental implant placement.

Insulin-like Growth Factor II Messenger RNA-binding Protein 3 in Salivary Gland Tumors

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) is strongly expressed in malignant tumors and has been associated with their aggressive behavior. The aim of this study was to evaluate the presence of IMP3 in a series of salivary gland tumors. The sample consisted of 9 pleomorphic adenomas (PA), 14 adenoid cystic carcinomas (ACC), and 13 mucoepidermoid carcinomas (MEC) that were investigated by immunohistochemical technique. All cases of PA and MEC were positive for IMP3 particularly in the cytoplasm. PA showed 4 cases as high expression and 6 as low expression. MEC showed 10 cases as low expression and 3 as high expression. For ACC, 4 cases were high expression, whereas 6 cases were low expression. No significant difference was observed between tumors (P>0.05, Fisher’s test) when both scores of IMP3 were compared. This study showed that MEC seems to be more sensitive to IMP3 than ACC and provided an insight into this protein in salivary gland tumors. Furthermore, although IMP3 is not a specific diagnostic marker to distinguish the tumors studied, it seems to mediate cell adhesion and migration in these tumors. Further studies should be performed to better understand the IMP3 biology in salivary gland tumors.

Evaluation of Mast Cell Density in the Tumor Microenvironment in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

The objective of this study was to compare mast cell density (MCD) in oral epithelial dysplasias (OED) and oral squamous cell carcinoma (OSCC) and determine its correlation with clinical and histopathologic parameters and the degree of tumor differentiation. Thirty OSCC samples, 14 OED samples, and 4 non-neoplastic oral mucosa samples were analyzed by immunohistochemistry to determine MCD based on the expression of MC tryptase. In addition, MCs were categorized morphologically into degranulated and granulated cells. MCD was significantly higher in OSCC lesions with a greater degree of differentiation (P=0.04). No significant difference in MCD was detected between mild and moderate OED samples (P=0.09). Our findings indicate that MCs are present in the tumor microenvironment and may be associated with a better prognosis.

Epithelioid hemangioma in the oral mucosa: A case report

Introduction Epithelioid hemangioma is an uncommon benign vasoproliferative neoplasm that usually manifests as multiple red nodules in middle-aged adults Case Outline 52-year-old male patient presented with a one-year history of a nodular lesion in the left buccal mucosa measuring 3 cm. The clinical hypothesis was lipoma. An excisional biopsy revealed a circumscribed lesion composed of lobules of vessels with perceptible or poor lumina, associated with a prominent inflammatory infiltrate consisting of eosinophils, histiocytes and chronic inflammatory cells. The endothelial cells composing the lesion had an epithelioid morphology and contained abundant eosinophilic cytoplasm. Immunohistochemistry for CD34, factor VIII, collagen IV, alpha-smooth muscle actin, and mast cells, as well as histochemical staining with Weigert’s orcein were performed. Conclusion Vascular proliferations of soft tissues are a diverse and morphologically complex group of lesions that are difficult to diagnose. This report presents a case of oral epithelioid hemangioma, highlighting relevant morphological and immunohistochemical features that could help distinguish this condition from other neoplasms.

Orthokeratinized odontogenic cyst: a report of two cases in the mandible

PURPOSE: To describe the behavior clinical and pathological features of two cases of odontogenic cyst orthokeratinized. CASE DESCRIPTION: In case 1, a 17-year-old woman presented hard and painless swelling in the left posterior mandible. Radiographically, a radiolucent area with a radiopaque was observed. A clinical diagnosis of ameloblastoma or odontogenic keratocystic tumor was established. The histopathological examination revealed an orthokeratinized odontogenic cyst. In case 2, a 23-year-old woman presented a radiolucent lesion surrounded by radiopaque halo symmetrically distributed on both partially erupted lower third molars. A clinical diagnosis of bilateral dentigerous cyst (DC) was rended. The histopathological examination showed bilateral orthokeratinized odontogenic cyst. CONCLUSION: Orthokeratinized odontogenic cyst should be considered in the differential diagnosis of lesions occurring in the jawbones associated with an impacted tooth, particularly those cases simulating dentigerous cyst. In addition, we observed the importance of radiographs taken prior to orthodontic treatment as an important tool in the diagnosis of oral pathologies. Performing routine radiograph is of high clinical value, especially before orthodontic treatment.