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.

This study evaluated the clinical and histopathologic aspects of 41 cases of oral lipomas diagnosed in a Brazilian population. All records from patients diagnosed with oral lipoma between 1970 and 2008 were reviewed. Histological sections were evaluated by light microscopy. There was a predominance of females (2.4:1), with a peak incidence between the sixth and seventh decade. The buccal mucosa was the most aVected site (53.7%), followed by the buccal sulcus (14.6%) and tongue (9.8%). Tumor size ranged from 0.5 to 10 cm and the mean reported duration was 48 months. Histologically, the following variants were identiWed: lipoma (41.5%), Wbrolipoma (34.1%), spindle cell lipoma (9.8%), sialolipoma (9.8%), osteolipoma (2.4%), and chondrolipoma (2.4%). Most tumors were well delimited, irrespective of the variant. Lipomas are rare tumors of the oral cavity. The characterization of new variants, such as sialolipomas, and the identiWcation of histological subtypes in already known variants, such as low-fat and fat-free spindle cell lipomas, highlight the importance for careful microscopic evaluation of these tumors, which might be combined with immunohistochemistry in some cases.

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.

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.

Adenomatoid odontogenic tumor (AOT) is an uncommon benign epithelial lesion of odontogenic origin and, thus far, only few studies regarding the frequency of its many histopathologic features have been published in the literature. Thus, the aim of this study was to perform a retrospective analysis in a case series of AOT, with emphasis on the histopathological features. Fifteen cases of AOT were studied considering their clinical, radiographic and histopathologic aspects. Twelve cases affected females and the mean age was 16.2 years. The anterior maxilla was the most common site (66.6 %) and radiographically most cases showed a unilocular radiolucency with well-defined borders (57.1 %). Histologically, most cases exhibited predominantly a solid growth pattern (46.7 %) or a similar proportion of solid and cribriform patterns (46.7 %). Eosinophilic amorphous material (''tumor droplets'') was found in all cases (100 %). Most tumors showed duct-like spaces (93.3 %) and convoluted structures (60.0 %) whereas a minor proportion of cases presented calcifying epithelial odontogenic tumor (CEOT)-like areas (26.7 %). Variable amounts of calcified material were found in most AOTs (80.0 %) whereas osteodentin and perivascular hyalinization were seen only rarely (6.7 % each one). Five (33.3 %) cases had areas mimicking a dentigerous cyst and most of these were diagnosed in females (80.0 %). Regarding the histopathologic features, our results suggest that AOTs usually show predominance of solid pattern or a similar proportion of solid and cribriform patterns while osteodentin and perivascular hyalinization are rarely seen in these tumors. In addition, areas mimicking a dentigerous cyst and CEOT-like areas are relatively infrequent findings in AOTs.