Leão Pereira Pinto

Odontogenic tumors: analysis of 127 cases

One hundred and twenty-seven cases of histologically confirmed odontogenic tumors were retrieved from a total of 5,289 oral and maxillary lesions diagnosed at the Division of Oral Pathology, Federal University of Rio Grande do Norte, during a period of 30 years (1970-1999). The most common histological diagnosis was odontoma (50.40%), followed by ameloblastoma (30.70%). The prevalence of odontogenic tumors was greater in females and the peak incidence occurred in the second and third decades of life. The main anatomical location was the mandible, and no malignant tumors were found.

Randomized trials for the treatment of burning mouth syndrome: an evidence-based review of the literature.

Burning mouth syndrome (BMS) is defined as a chronic pain condition, characterized symptomatically by a generalized or localized burning sensation in the oral cavity. Various drugs have been used in attempting to treat BMS, but there is insufficient evidence to show the effect of any effective treatment. The aim of this review was to assess the effectiveness of therapies for BMS. Randomized controlled trials (RCTs) enrolling patients with a diagnosis of BMS were identified by searching Pubmed and Scoppus databases. The methodological quality of included studies was assessed on the basis of the method of allocation concealment, blindness of the study, loss of participants, size sample, and outcome concealment. A total of 12 relevant articles were analyzed. Therapies that used capsaicin, alpha-lipoic acid (ALA), and clonazepam were those that showed more reduction in symptoms of BMS. However, many studies of therapeutic interventions in BMS lack consistency in their results, because they use in their methodology, sample and a relatively short time of therapy and often do not provide a follow-up of patients treated. Thus, future studies are required to establish the treatment for patients suffering from this chronic and painful syndrome.

Evaluation of an oral preventive protocol in children with acute lymphoblastic leukemia

This study was designed to assess the effectiveness of a preventive oral protocol in children receiving antineoplastic treatment for acute lymphoblastic leukemia (ALL) before initiating a larger intervention study. During a seven month period, fourteen children from two to ten years old with a diagnosis of ALL were evaluated. Patients with ALL who received a 0.12% chlorhexidine mouth rinse (seven children) were compared to a control group of patients who were not given the same preventive treatment (seven children) as to the occurrence of oral mucosal complications. Children in both groups received daily oral hygiene care, and were examined daily by the pediatric dentistry team until discharge. A significant decrease in the incidence of oral mucositis and ulceration was observed in the children who received a 0.12% chlorhexidine mouth rinse (p < 0.05 by Fishers exact test). The findings obtained in the present trial are encouraging, and suggest that the systematic application of a preventive protocol reduces the incidence of oral complications in children with ALL receiving chemotherapy.

Proliferating Cell Nuclear Antigen (PCNA) and p53 Protein Expression in Ameloblastoma and Adenomatoid Odontogenic Tumor

In this study, proliferating cell nuclear antigen (PCNA) and p53 protein expressions were analyzed in 16 cases of ameloblastoma and 8 cases of adenomatoid odontogenic tumor (AOT). The cases of ameloblastoma consisted of solid type tumors and histologic arrangements of different subtypes were observed. In some specimens, more than one histologic subtype was identified in the same lesion, and each tumor was categorized according to the predominant cell pattern. The odontogenic tumors were grouped as follows: follicular ameloblastoma (n=7), plexiform ameloblastoma (n=4), acanthomatous + follicular ameloblastoma (n=3), basal cell ameloblastoma (n=2), adenomatoid odontogenic tumor (n=8). PCNA immunohistochemical expression revealed stronger quantitative labeling index for the follicular ameloblastoma, while for p53 protein the strongest quantitative labeling index was detected in the plexiform type. Nevertheless, statistical analysis using ANOVA and Tukeys test did not detect significant differences (p>0.05) among the histologic subtypes of ameloblastoma. The findings of this study suggest that the different histologic patterns of ameloblastoma did not show a direct correlation with their clinical behavior and consequently with the prognosis of the cases. The results also indicated that the ameloblastoma has greater proliferative potential than the AOT, which can contribute to explain its more aggressive and invasive characteristics.

Frequency of oral mucositis and microbiological analysis in children with acute lymphoblastic leukemia treated with 0.12% chlorhexidine gluconate

In view of the morbidity potential of oral complications in patients with leukemia, this study evaluated the clinical and microbiological alterations that occur in the oral mucosa of children with acute lymphoblastic leukemia (ALL) undergoing antineoplastic chemotherapy and prophylactic administration of 0.12% chlorhexidine gluconate. The sample consisted of 17 children aged 2 to 12 years that underwent clinical examination of the oral mucosa for the detection of oral lesions. In addition, biological material was collected from labial and buccal mucosa for microbiological analysis. Oral mucositis was observed in only 5 (29.4%) patients. Microbiological analysis revealed a reduced number of potentially pathogenic microorganisms, such as coagulase-negative staphylococci (47%), Candida albicans (35.3%), Klebsiella pneumoniae (5.9%), enteropathogenic Escherichia coli (5.9%), and Stenotrophomonas maltophilia (5.9%). Patients with oral mucositis showed a higher frequency of coagulase-negative staphylococci (80%) when compared with patients with normal oral mucosa (33.3%). In conclusion, the results of the present study suggest that the prophylactic use of 0.12% chlorhexidine gluconate reduces the frequency of oral mucositis and oral pathogens in children with ALL. In addition, the present findings suggest a possible relationship between coagulase-negative staphylococci and the development of oral mucositis.

Immunohistochemical expression of mast cell tryptase in giant cell fibroma and inflammatory fibrous hyperplasia of the oral mucosa

This study analysed the immunohistochemical expression of mast cell tryptase in giant cell fibromas (GCFs). In addition, the possible interaction of mast cells with stellate giant cells, as well as their role in fibrosis and tumour progression, was investigated. For this purpose, the results were compared with cases of inflammatory fibrous hyperplasia (IFH) and normal oral mucosa. Thirty cases of GCF, 30 cases of IFH and 10 normal mucosa specimens used as control were selected. Immunoreactivity of mast cells to the anti-tryptase antibody was analysed quantitatively in the lining epithelium and in connective tissue. In the epithelial component (p=0.250) and connective tissue (p=0.001), the largest mean number of mast cells was observed in IFHs and the smallest mean number in GCFs. In connective tissue, the mean percentage of degranulated mast cells was higher in GCFs than in IFHs and normal mucosa specimens (p<0.001). Analysis of the percentage of degranulated mast cells in areas of fibrosis and at the periphery of blood vessels also showed a larger mean number in GCFs compared to IFHs and normal mucosa specimens (p<0.001). The percent interaction between mast cells and stellate giant cells in GCFs was 59.62%. In conclusion, although mast cells were less numerous in GCFs, the cells exhibited a significant interaction with stellate giant cells present in these tumours. In addition, the results suggest the involvement of mast cells in the induction of fibrosis and modulation of endothelial cell function in GCFs.

Clinicopathologic analysis of 7 cases of oral schwannoma and review of the literature

Schwannomas, also known as neurilemmomas, are uncommon neoplasms apparently derived from Schwann cells. The growth of these tumors causes displacement and compression of the nerve of origin. Schwannomas are usually solitary lesions but can be multiple when associated with neurofibromatosis. Anti-S100 protein is the most widely used antibody for the identification of this neoplasm. Surgical excision is the treatment of choice for schwannomas, with few and controversial reports of recurrence or malignant transformation. The present article reports 7 additional cases of oral schwannoma, and the literature is reviewed regarding clinicopathologic features, immunohistochemical findings, differential diagnosis, and therapeutic management of this benign neural tumor.

Nonodontogenic cysts of the oral and maxillofacial region: demographic profile in a Brazilian population over a 40-year period

The aim of the study was to determine the distribution of histologically diagnosed nonodontogenic cysts (nOCs) over a 40-year period in a Brazilian population. Biopsy records from patients with nOC from the files of the Oral Pathology Service during the period of 1970–2009 were evaluated. Among 10,311 oral biopsies, 58 met the criteria of nOCs. The most frequent nOCs were nasopalatine duct cysts (32.8%), followed by epidermoid cysts (20.7%) and oral lymphoepithelial cysts (17.2%). Nasopalatine duct cysts showed predominance among females (68.4%). Epidermoid cysts were most commonly found in the floor of the mouth (36.4%), tongue (27.3%), and buccal mucosa (27.3%). Oral lymphoepithelial cysts exhibited female prevalence (80.0%) and were commonly located in the tongue (44.4%). The frequency of nOCs found in the population studied here is slightly different from those reported in other case series. Nasopalatine duct cysts, epidermoid cysts, and oral lymphoepithelial cysts were the most common nOCs found, accounting for 70.7% of all nOCs.

Changes in immunoexpression of E-cadherin and β-catenin in oral squamous cell carcinoma with and without nodal metastasis

The aim of this study is to analyze the immunohistochemical expression of E-cadherin and beta-catenin in oral squamous cell carcinoma to better understand the biological behavior of this lesion. The sample consisted of 15 cases of the tongue and 15 of the lower lip. The pattern and intensity of the labeling and the analysis of the percentage of tumor cells immunopositive in membrane for E-cadherin and beta-catenin were related to the anatomic location of the lesion, the presence or absence of nodal metastasis, and the histological gradation of malignancy in the tumor invasion front. The presence or absence of cytoplasmic and nuclear labeling was also recorded. The membrane expression for E-cadherin and beta-catenin predominately displayed a heterogeneous pattern in the carcinomas studied. No significant difference was observed between the expression pattern and the quantity of cells immunopositive for E-cadherin and beta-catenin and the anatomic location of the lesion or the presence or absence of nodal metastasis. However, a statistically significant difference was found between the reduced expressio\n of these proteins and the high malignancy score. The reduced immunoexpression of these proteins in the membrane may be related to the high degree of cell indifferentiation in cases of oral squamous cell carcinoma with high scores.

High-risk human papillomavirus (HPV) is not associated with p53 and bcl-2 expression in oral squamous cell carcinomas.

OBJECTIVE To determine the frequency and type of human papillomavirus (HPV) in oral squamous cell carcinomas (OSCC), as well as to identify a possible association between HPV infection and the expression pattern of p53 and bcl-2, and identify whether the oral HPV infection is a characteristic finding in our sample. METHODS We performed polymerase chain reaction and dot blot hybridization for the detection of HPV DNA in paraffin sections as well as immunohistochemical analysis of p53 and bcl-2 in our sample. RESULTS Twenty-six cases (29.5%) were positive for the virus by PCR. Dot blot hybridization identified HPV 18 in 21 (80.8%) cases, HPV 16 in one (3.8%) case and a combination of the two types in the four (15.4%) remaining cases. No other type of HPV was detected in the sample. Immunohistochemistry showed p53 in 26 (60.4%) cases and bcl-2 in 17 (39.5%) ones. No significant association was observed between the presence of HPV and the expression of the proteins studied (p=0.988 and p=0.748, respectively). CONCLUSIONS Although this investigation have detected only 29.5% of HR-HPV DNA in OSCC, it is possible that this virus contribute to the development of some case of this tumor. Furthermore, it seems that the immunohistochemical expression of p53 and bcl-2 and the presence of HPV DNA are independent events in OSCC.