Dendritic cell subpopulations in carcinoma ex-pleomorphic adenoma: A multicenter study.

OBJECTIVE: Carcinoma ex-pleomorphic adenoma (CEXPA) represents a malignant transformation from a recurrent or primary pleomorphic adenoma (PA), and the immune response may be essential in this process. Therefore, in this study, we aimed to identify and quantify subpopulations of dendritic cells (DCs) in CEXPA, residual PA in CEXPA (rPA), and PA. MATERIALS AND METHODS: A multicenter study was performed collecting salivary gland tumor (SGT) samples from three Oral and Maxillofacial Pathology Centers. A tissue microarray containing 41 samples of CEXPA and 22 samples of PA was included in this study and submitted to immunohistochemical reactions against CD1a, CD83, CD207, and Ki67 antibodies. RESULTS: Both PA and rPA showed a higher quantification of CD207+ and CD83+ cells when compared to CEXPA (p < 0.001 and p < 0.01, respectively). There was also a difference when comparing the cell proliferation index between PA/rPA and CEXPA using the Ki-67 marker (p = 0.043). However, there was no difference in the DC population regarding clinical parameters such as sex, anatomical location, size, and metastases (p > 0.06). CONCLUSIONS: Immunohistochemical profile of DC subpopulations and cell proliferation biomarkers in SGTs can contribute as an important tool in the differentiation of benign and malignant tumors or detection of initial areas with malignant transformation.

Oral solitary fibrous tumors: A collaborative clinicopathologic study of 19 cases.

OBJECTIVE: To report the clinicopathologic features of 19 oral solitary fibrous tumors (SFTs). METHODS: Clinical data were collected from the records of seven pathology services. All cases were re-evaluated by HE staining and confirmed by immunohistochemistry. RESULTS: The series comprised 11 females (57.9%) and 8 males (42.1%), with a mean age of 47.3 ± 14.7 years (range: 22-71 years) and a 1.3:1 female-to-male ratio. Most tumors affected the buccal mucosa (n = 7; 36.8%) and presented clinically as an asymptomatic solitary submucosal well-circumscribed nodule with coloration similar to the oral mucosa. Morphologically, most SFTs (n = 10; 52.6%) exhibited a classic hybrid pattern characterized by a well-circumscribed proliferation of densely cellular areas alternating with hypocellular areas in a variably collagenous vascular stroma. Remnants of accessory salivary glands were observed in two cases (n = 2; 10.5%). All tumors were positive for STAT6 and CD34 (n = 19; 100%). Outcome information was available from 6 patients (31.6%), with clinical follow-up ranging from 6 to 24 months (mean ± SD, 9.5 ± 6.8 months), and none developed local recurrence. CONCLUSIONS: Oral SFTs are rare and often clinically misdiagnosed. Pathologists should consider SFT in the differential diagnosis of oral spindle cell tumors. Accurate diagnosis requires careful morphological evaluation supported by immunohistochemical analysis.

Is cysteamine use effective in the treatment of melasma? A systematic review and meta-analysis.

Melasma is a recurrent hypermelanosis disorder characterized by the appearance of brownish and symmetrical spots on the skin. It affects the quality of life and is resistant to available treatment approaches. Cysteamine has been reported as a promising depigmenting agent for melasma treatment and following formulation enhancement, its use is being reported. This review aimed to evaluate the efficacy of the use of depigmenting formulations containing 5% cysteamine in the treatment of patients with melasma. A systematic search was performed in PubMed, Science Direct, and Scielo databases until December 27, 2021, based on criteria selected by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Statistical analysis was performed with Review Manager 5.4 software. The risk of bias was assessed using the Cochrane Risk of Bias Tool for Randomized Trials. A total of six studies containing 120 melasma patients treated with 5% cysteamine were included in this meta-analysis. The meta-analysis demonstrated that 5% cysteamine is effective for the treatment of patients with melasma (MD 6.26 [95% CI 3.68-8.83], p < 0.0001, I2  = 86%). In this review, through meta-analysis allows concluding that 5% cysteamine is effective in the treatment of melasma and presents a low probability of side or adverse effects.

Hesperetin-Based Hydrogels Protect the Skin against UV Radiation-Induced Damage.

UV radiation can cause damages, such as erythema, skin photoaging, and carcinogenesis. The adoption of protective measures against sun exposure is essential to prevent these damages, and the interest in using natural substances as an alternative for photoprotection is growing. Thus, hesperetin with antioxidant, anti-inflammatory, and anticancer properties is a promising substance to be used with photochemopreventive action and to protect the skin from damage induced by UV radiation. Therefore, the present study aimed to develop a topical formulation based on AAMVPC gel containing hesperetin and evaluate its photoprotective effect on the skin of rats exposed to UVA-UVB radiation. The animals were submitted to the irradiation protocol UVA-UVB, and at the end, erythema, lipid peroxidation, and activity of the antioxidant enzyme catalase and superoxide dismutase were evaluated. Additionally, it evaluated the activity of myeloperoxidase and histological changes. The formulation presented a rheological and spreadability profile suitable for cutaneous application. In vivo results demonstrated that the topical formulation of AAMVPC gel containing hesperetin at a concentration of 10% protected the skin from damage induced by UVA-UVB radiation, with the absence of erythema, lipid lipoperoxidation, and inflammation (low myeloperoxidase activity), and increased catalase and superoxide dismutase activities. The morphology and architecture of the dermo-epidermal tissue of these animals were like those observed under normal conditions (non-irradiated animals). Thus, the results showed that hesperetin was able to protect the animals' skin against UV radiation-induced skin damage and the protection mechanisms may be related to the antioxidant and anti-inflammatory properties of this natural product.

Sialolipomas of minor salivary glands: A multi-institutional study and literature review.

BACKGROUND: Sialolipoma is a rare histological variant of lipoma commonly misdiagnosed and composed of a proliferation of mature adipocytes with secondary entrapment of normal salivary gland tissue. The purpose of the present study is to report the clinicopathologic and immunohistochemical features of 10 new cases of sialolipomas in conjunction with a review of the literature. METHODS: A retrospective descriptive cross-sectional study was performed. A total of 54,190 biopsy records of oral and maxillofacial lesions from four oral and maxillofacial pathology services in Brazil were analysed. All cases of lipomas were reviewed, and clinical, demographic and histopathological data were collected of all cases compatible with sialolipomas. In addition, immunohistochemistry stains (AE1/AE3, CK7, 34ßE12, S-100, HHF35, α-SMA and Ki-67) and a literature review based on a search of three electronic databases (PubMed, Web of Science and Scopus) were performed. RESULTS: Among all lipomas reviewed, there were 10 cases of sialolipomas. The series comprised of 7 females (70.0%) and 3 males (30.0%), with a mean age of 46.1 ± 21.5 years (range: 11-71 years) and a 2.3:1 female-to-male ratio. The lower lip (n = 3, 30.0%) and tongue (n = 2, 20.0%) were the most common locations, presenting clinically as a nodule of slow growth and normal colour. Conservative surgical excision was the treatment in all cases. No recurrence was observed. CONCLUSION: Sialolipomas are a rare histological variant of lipoma, affecting the salivary glands, mainly in the parotid gland and palate of female adults. Pathologists must recognise sialolipomas to avoid misdiagnoses with other lipomatous tumours that can affect salivary glands.

Oral focal mucinosis: A multi-institutional study and literature review.

BACKGROUND: Oral focal mucinosis (OFM) is a rare benign condition of unknown etiology, considered the oral counterpart of cutaneous focal mucinosis. We report the clinicopathologic features of 21 cases of OFM in conjunction with a review of the literature. METHODS: Clinical data were collected from the records of five oral and maxillofacial pathology services. All cases were evaluated by hematoxylin and eosin staining, histochemistry, and immunohistochemistry (vimentin, S-100, α-SMA, CD34, and mast cell). RESULTS: The series comprised 14 females (66.7%) and seven males (33.3%), with a mean age of 48.2 ± 20.7 years (range: 8-77 years) and a 2:1 female-to-male ratio. Most of the lesions affected the gingiva (n = 6, 28.6%) and presented clinically as asymptomatic sessile or pedunculated nodules with fibrous or hyperplasic appearance. All cases were negative for S-100 protein, CD34, and α-SMA and positive for Alcian blue staining. Conservative surgical excision was the treatment in all cases, and there was only one recurrence. CONCLUSION: OFM is a rare benign disorder that is often clinically misdiagnosed as reactive lesions or benign proliferative processes. Dermatologists and pathologists should consider OFM in the differential diagnosis of soft tissue lesions in the oral cavity, mainly located in the gingiva.

An extensive intraoral blue nevus in an elder patient.

OBJECTIVE: To report a rare case of intraoral extensive blue nevus in an elder patient. BACKGROUND: Oral blue nevi is a well-recognised skin melanocytic neoplasm that rarely occurs in the oral cavity and may mimic melanoma in the early stages. METHODS: An incisional biopsy was performed, and the diagnosis was blue nevus. CONCLUSION: Both the clinician and pathologist must be aware of such a presentation to diagnose and treat appropriately.

Anti-inflammatory and antioxidant activity of carvacrol in the respiratory system: A systematic review and meta-analysis.

Carvacrol is a monoterpene present in the essential oil of a number of plants and has been widely used in traditional medicine because it is considered to have a range of therapeutic effects including in relation to respiratory disease. To conduct a systematic review and meta-analysis to assess the anti-inflammatory and antioxidant activities of carvacrol when used in the treatment of respiratory disorders. A comprehensive literature search using Scopus, MEDLINE-PubMed, Cochrane and Web of Science was undertaken. Papers related to the anti-inflammatory or antioxidant properties of carvacrol in the treatment of an injury in the respiratory system in in vivo studies and published in the period up to and including August 2019. A total of 152 studies were initially identified, with only 17 meeting the inclusion criteria. Five of the studies were performed in humans, and 12 were performed in rodents. Among the 17 studies included in the systematic review, we performed the meta-analysis with nine of the studies with animals. Carvacrol had a positive effect on the reduction of interleukin (IL)-1ß, IL-4, IL-8 and malondialdehyde (MDA); however, the analysis indicated that carvacrol had no effect on IL-6 and tumor necrosis factor alpha (TNF-α), probably due to the methodological quality of the studies and their heterogeneity. Current evidence supports the antioxidant and anti-inflammatory effects of carvacrol, but its relationship with the reduction of some inflammatory mediators in animals with lung injury needs further elucidation.

Gingival squamous cell carcinoma mimicking a non-neoplastic proliferative lesion in an older patient.

OBJECTIVE: To report a case of gingival squamous cell carcinoma (SCC) in an elderly patient mimicking a non-neoplastic proliferative lesion. BACKGROUND: Oral SCC is a well-recognised malignancy of the oral cavity that may mimic benign reactive proliferative processes. METHODS: An excisional biopsy was performed, and the diagnosis was gingival SCC. CONCLUSION: It is essential that both the clinician and pathologist to be aware of such a presentation to allow for proper diagnosis and treatment.

KRAS mutations drive adenomatoid odontogenic tumor and are independent of clinicopathological features.

Adenomatoid odontogenic tumor is a benign encapsulated epithelial odontogenic tumor that shows an indolent clinical behavior. We have reported in a few adenomatoid odontogenic tumors mutations in KRAS, which is a proto-oncogene frequently mutated in cancer such as lung, pancreas, and colorectal adenocarcinomas. We aimed to assess KRAS mutations in the hotspot codons 12, 13, and 61 in a large cohort of adenomatoid odontogenic tumors and to test the association of these mutations with clinical (age, site, tumor size, follicular/extrafollicular subtypes) and histopathological parameters. Thirty eight central cases were studied. KRAS codon 12 mutations were assessed by TaqMan allele-specific qPCR (p.G12V/R) and/or Sanger sequencing, and codon 13 and 61 mutations were screened by Sanger. Histological tumor capsule thickness was evaluated by morphometric analysis. Additionally, the phosphorylated form of the MAPK downstream effector ERK1/2 was investigated. Statistical analysis was carried out to test the association of KRAS mutations with clinicopathological parameters. KRAS c.35 G >T mutation, leading to p.G12V, was detected in 15 cases. A novel mutation in adenomatoid odontogenic tumor, c.34 G >C, leading to p.G12R, was detected in 12 cases and the other 11 were wild-type. Codon 12 mutations were not associated with the clinicopathological parameters tested. RAS mutations are known to activate the MAPK pathway, and we show that adenomatoid odontogenic tumors express phosphorylated ERK1/2. In conclusion, a high proportion of adenomatoid odontogenic tumors (27/38, 71%) have KRAS codon 12 mutations, which occur independently of the clinicopathological features evaluated. Collectively, these findings indicate that KRAS mutations and MAPK pathway activation are the common features of this tumor and some cancer types. Although it is unclear why different codon 12 alleles occur in different disease contexts and the complex interactions between tumor genotype and phenotype need clarification, on the basis of our results the presence of KRAS p.G12V/R favors the adenomatoid odontogenic tumor diagnosis in challenging oral neoplasm cases.

Effect of laser photobiomodulation on the periodontal repair process of replanted teeth.

BACKGROUND/AIM: Tooth replantation is the optimal treatment in cases of avulsion. However, its success is limited due to the occurrence of external root resorption. The aim of this study was to assess the effect of laser photobiomodulation (LPBM) at λ808 nm and λ660 nm and of storage media on the periodontal repair process of replanted teeth in rats. MATERIAL AND METHODS: Sixty maxillary right incisors were extracted from sixty Wistar rats and randomly assigned to six groups (n = 10). Groups consisted of 10 teeth stored in paper napkins (PN), whole milk (WM), and soy milk (SM), for 45 min; and PNL, WML and SML, in which teeth were stored in the same storage media, but the root surface and the alveolus were treated with LPBM at λ808 nm before replantation, and the buccal and palatal mucosa of the alveolus were treated with LPBM at λ660 nm after replantation. Five rats from each group were euthanized after 15 or 30 days. The right hemimaxilla including the replanted incisor was removed and processed for histomorphometric analysis to assess root resorption areas, replacement root resorption, perimeter with ankylosis and periodontal repair, and areas of type I and III collagen deposition, using the ImageJ 1.50b software. Data were analyzed statistically by anova followed by Tukey's multiple comparison test (α = 5%). RESULTS: WM and SM showed smaller root resorption areas and higher collagen deposition in both experimental periods, and SM showed the largest perimeter of periodontal repair. LPBM reduced the occurrence of root resorption only in the PNL group, both at 15 and 30 days, and increased the perimeter of periodontal repair in all groups at 30 days. There was higher collagen deposition in the irradiated groups regardless of the experimental period. CONCLUSIONS: The LPBM protocol at λ808 nm and λ660 nm as well as whole milk and soy milk favored the periodontal repair process of replanted teeth in rats.

Hydroalcoholic extract of red propolis promotes functional recovery and axon repair after sciatic nerve injury in rats.

CONTEXT: Peripheral axon injury and degeneration are often mediated by oxidative stress and inflammation. The hydroalcoholic extract of the red propolis (HERP) has attracted great attention because of its antioxidant and anti-inflammatory activities. OBJECTIVE: The objective of this work is to study the effect of HERP on nerve repair and functional recovery after sciatic nerve injury (SNI) in rats. MATERIALS AND METHODS: The chemical markers in HERP were identified using high-resolution mass spectroscopy. After axonotmesis of sciatic nerve, ibuprofen (IBP) and HERP treatments were orally administered for 28 d. Behavioural tests were performed weekly after SNI. The myelinated axon number was counted using morphometric analysis. RESULTS: The compounds found in HERP were pinocembrin, formononetin, vestitol, and biochanin A. The animals that underwent SNI showed a significant decrease in motor function based on the Basso, Beattie and Bresnahan scale and sciatic functional index compared with sham animals until 7 d after the surgery (p < 0.05). After 14 and 21 d, the SNI groups treated with either HERP or IBP showed significant improvement (p < 0.01), and the SNI group treated with HERP 10 mg/kg showed accelerated motor recovery compared with the other groups (p < 0.01). SNI caused also a reduction in the myelinated axon counts, and treatment with HERP 10 mg/kg induced a significant increase in the number of myelinated fibres compared with all other groups. CONCLUSION: HERP promoted regenerative responses and accelerated functional recovery after sciatic nerve crush. Thus, it can be considered to be a new strategy or complementary therapy for treating nerve injuries.

Traumatic ulcerative granuloma with stromal eosinophilia mimicking a squamous cell carcinoma.

Traumatic ulcerative granuloma with stromal eosinophilia (TUGSE) is a rare lesion of a traumatic-reactive nature of the oral mucosa that can clinically mimic an oral carcinoma. A 59-year-old male patient presented painful ulceration with indurated margins on the base of the tongue, extending to the floor of the mouth. The use of ill-fitting denture hurting the mucosa of the region was reported by the patient. The evolution time was 45 days. The presumptive diagnoses were oral squamous cell carcinoma and chronic ulcer. An incisional biopsy revealed an ulceration associated with an eosinophil-rich inflammatory infiltrate and a bed of proliferating histiocyte-like cells in either diffuse or fasciculate arrangement. There was diffuse immunopositivity for CD3, but focal for CD68 and α-SMA, and negativity for CD30. The final diagnosis was TUGSE. The use of the ill-fitting dental prosthesis was suspended and the lesion had complete spontaneous remission three weeks later. TUGSE is an uncommon traumatic self-limiting lesion that must be included in the differential diagnosis of ulcerative lesions resembling oral cancer. The correlation of clinical and histopathological findings is pivotal for a proper diagnosis, avoiding unnecessary aggressive surgical approaches. Key words:Oral ulcer, eosinophilia, immunohistochemical, differential diagnosis.

Oral granular cell tumor: a collaborative clinicopathological study of 61 cases.

BACKGROUND: Granular Cell Tumor (GCT) is an uncommon benign lesion in the oral cavity whose pathogenesis remains poorly understood. Due to their infrequent occurrence and similarity to other oral lesions, they are often forgotten during the initial clinical diagnosis. Therefore, understanding its prevalence, clinical and pathological characteristics is crucial for an accurate diagnosis and adequate management. METHODS: All cases diagnosed as GCTs in six Brazilian and Argentinian oral diagnostic centers were re-evaluated by HE staining, and clinical, demographic, and histopathological data were collected and evaluated. RESULTS: The series comprised 45 female (73.8%) and 16 male (26.2%), with a 2.8:1 female-to-male ratio and a mean age of 35.3 ± 16.9 years (range: 7-77 years). Most cases occurred on the tongue (n = 49; 81.6%) and presented clinically as asymptomatic papules or nodules (n = 50; 89.3%) with a normochromic (n = 25; 45.5%) or yellowish (n = 11; 20.0%) coloration and sizes ranging from 0.2 to 3.0 cm (mean ± SD: 1.40 ± 0.75 cm). Morphologically, most tumors were characterized by a poorly delimited proliferation (n = 52; 88.1%) of cells typically rounded to polygonal containing abundant, eosinophilic, finely granular cytoplasm. Pustulo-ovoid bodies of Milian were identified in all lesions (n = 61; 100%). Entrapment of skeletal striated muscle (n = 44; 72.1%) and nerve fibers (n = 42; 68.9%) were common findings. Pseudoepitheliomatous hyperplasia (PEH) was observed in 23 cases (39.0%). In only 27.7% of cases (n = 13) there was agreement between the clinical and histopathological diagnosis. Outcome information was available from 16 patients (26.2%), with clinical follow-up ranging from 4 to 36 months (mean 13.3 months), and none developed local recurrence. CONCLUSIONS: The clinical and histopathological features of GCTs were consistent with those described in previous studies. In general, these lesions have a predilection for the lateral region of the tongue in adult women. It is essential to consider GCTs in the differential diagnosis of yellow or normochromic papules and nodules in the oral cavity. Histopathological evaluation is essential for the definitive diagnosis and the prognosis is excellent.

Clinicopathologic and imaging features of odontogenic myxomas: a multi-institutional study.

PURPOSE: This study aims to report clinicopathologic and imaging features of odontogenic myxomas (OM), highlighting uncommon findings. METHODS: Clinicopathologic and imaging data of OMs diagnosed in the five Brazilian diagnostic pathology centers were collected and analyzed. RESULTS: The series comprised 42 females (68.9%) and 19 males (31.1%), with a 2.2:1 female-to-male ratio and a mean age of 34.5±15.4 years (range: 4-80). Clinically, most OMs presented as painless intraoral swelling (n = 36; 70.6%) in the mandible (n=37; 59.7%). Multilocular lesions (n=30; 83.3%) were more common than unilocular lesions (n=6; 16.7%). There was no statistically significant difference between the average size of unilocular and multilocular OMs (p=0.2431). The borders of OMs were mainly well-defined (n=24; 66.7%) with different degrees of cortication. Only seven tumors caused tooth resorption (15.9%), while 24 (54.5%) caused tooth displacement. Cortical bone perforation was observed in 12 (38.7%) cases. Morphologically, OMs were characterized mainly by stellate or spindle-shaped cells in a myxoid background (n=53; 85.5%). Surgical resection was the most common treatment modality (n=15; 65.2%), followed by conservative surgery (n=8; 34.8%). Outcomes were available in 20 cases (32.3%). Seven of these patients had local recurrence (35%). Enucleation was the treatment with the highest recurrence rate (4/7; 57.1%). CONCLUSIONS: OM has a predilection for the posterior region of the jaws of female adults. Despite their bland morphological appearance, they displayed diverse imaging features. Clinicians must include the OM in the differential diagnosis of osteolytic lesions of the jaws. A long follow-up is needed to monitor possible recurrences.

CD1a-positive Langerhans cells and their relationship with E-cadherin in ameloblastomas and keratocystic odontogenic tumors.

BACKGROUND: Ameloblastomas and keratocystic odontogenic tumors (KOTs) are lesions that are characterized by locally invasive growth and cause extensive bone destruction. In addition, it is known that E-cadherin influences the adhesion of Langerhans cells (LCs) to keratinocytes. OBJECTIVE AND METHODS: The aim of this study was to investigate, using immunohistochemistry, the distribution of CD1a-positive cells in ameloblastomas and KOTs and their relationship with E-cadherin, in comparison to calcifying cystic odontogenic tumor (CCOT). RESULTS: The CD1a-positive LCs were observed in 11 ameloblastomas and KOTs. All of the cases of CCOT showed CD1a-positive LCs and a significant difference was found when this tumor was compared with ameloblastomas (P < 0.05, Mann-Whitney test). A statistically significant difference was also noted when comparing CD1a-positive LCs between CCOTs and KOTs (P < 0.05, Mann-Whitney test). Lower expression of E-cadherin in ameloblastomas (AMs) in relation to KOTs and CCOTs (P < 0.05, Fisher test) was observed. There was no correlation between E-cadherin and CD1a-positive LCs between all odontogenic tumors that were studied (P > 0.05, Spearman test). CONCLUSION: A quantitative difference of CD1a-positive cells between AMs and KOTs in comparison to CCOTs was observed. This permits to speculate that a depletion of CD1a-positive LCs might influence the local invasiveness of ameloblastomas and KOTs. Furthermore, it is suggested that E-cadherin mediates cell adhesion in these tumors.

Polymeric Nanoparticles for the Treatment of Prostate Cancer- Technological Prospecting and Critical Analysis.

BACKGROUND: Polymeric nanoparticles have a wide diversity, and due to their toxicity and biodegradability, they have been widely used in the health area. Its use allows stability of some compounds, targeted delivery, and increased half-life, in this context, making some treatment proposals more effective. Prostate cancer, in turn, is among the types of cancer with the highest mortality, and the lack of effective treatment causes several strategies to meet this need. OBJECTIVE: The objective of this work was to verify patents that use polymeric nanoparticles for the treatment of prostate cancer. METHODS: For that, specific keywords to direct the search were applied in Patent Scope. After obtaining the patents, one was selected for the development of critical analysis in relation to its chemistry and biology. RESULTS: A total of five patents were found and, of these, an invention that used PCL-PLGA-PEGCOOH polymeric nanoparticles with two natural compounds, resveratrol and celastrol, providing an alternative method to traditional monotherapies. CONCLUSION: The prospective analysis serves to direct us in relation to the technologies currently used in certain fields. Based on several cases of cancer and specifically the countless cases of prostate cancer, five recent patents were found using polymeric nanoparticles. However, only one brought a different aspect of all the treatments used lately. It brought an invention containing two natural compounds being carried with polymeric nanoparticles with promising results.

A rare case of mucoepidermoid carcinoma ex-pleomorphic adenoma of the hard palate.

Carcinoma Ex-Pleomorphic Adenoma (CExPA) is a salivary gland carcinoma derived from a primary or recurrent benign pleomorphic adenoma (PA) extremely rare in minor salivary glands. In this paper, we report the case of a male afrodescendant patient, 37 years old, presenting a palatal irregular nodular lesion with approximately 3.5 cm diameter. The lesion had over two years of evolution, but started growing faster and presenting pain and ulceration in the last two months. The incisional biopsy revealed a typical pleomorphic adenoma with focal areas of nests of epidermoid and mucous cells, as well as microcyst formations, resembling the mucoepidermoid carcinoma (MEC). Immunohistochemical analysis revealed positivity for CK7, CK13, CK 14, p63 and Ki67 (about 30%), whereas α-SMA was restricted to the PA component. The diagnosis was CExPA (MEC-type). A discussion on the histopathological and immunohistochemical criteria for differential diagnosis of CExPA is provided in this work, hoping to contribute to a better knowledge and understanding of this rare malignant tumor. Key words:Salivary gland neoplasms, pleomorphic adenoma, adenocarcinoma, mucoepidermoid carcinoma, pathology, differential diagnosis.

Naringin improves post-ischemic myocardial injury by activation of KATP channels.

Naringin (NRG) is a flavonoid with recognized cardioprotective effects. Then, it was investigated the cardioprotective mechanisms of NRG against ischemia-reperfusion (I/R) injury. The rats were pretreated for 7 days (v.o.) with NRG (25 mg/kg) or n-acetylcysteine (NAC, 100 mg/kg) and their isolated hearts were subjected to global ischemia (30 min) and reperfusion (60 min). Furthermore, isolated hearts were perfused with 5 µM NRG in the presence of 10 µM glibenclamide (GLI) and subjected to I/R protocol. In healthy ventricular cardiomyocyte, it was evaluated the acute effect of 5 µM NRG on the GLI sensitive current. The results showed that NRG pretreatment restored the cardiac function and electrocardiogram (ECG) alterations induced by I/R injury, decreasing arrhythmia scores and the occurrence of severe arrhythmias. Lactate dehydrogenase and infarct area were decreased while superoxide dismutase (SOD), catalase and citrate synthase activities increased. Expression of SOD CuZn and SOD Mn not was altered. NRG treatment decreased reactive oxygen species (ROS) generation and lipid peroxidation without alter sulfhydryl groups and protein carbonylation. Also, NRG (5 µM) increased the glibenclamide sensitive current in isolated cardiomyocytes. In isolated heart, the cardioprotection of NRG was significantly reduced by GLI. Furthermore, NRG promoted downregulation of Bax expression and Bax/Bcl-2. Histopathological analysis showed that NRG decreased cell edema, cardiomyocytes and nucleus diameter. Thus, NRG has a cardioprotective effect against cardiac I/R injury which is mediated by its antioxidant and antiapoptotic actions and KATP channels activation.