Desordens potencialmente malignas orais: análise clínica e patológica retrospectiva de 953 casos com ênfase na displasia epitelial oral

Abstract

Oral potentially malignant disorders are a group of entities that carry a higher risk to progress do oral squamous cell carcinoma. This process is influenced by numerous clinical, histological and molecular features associated with the lesions. The grade of dysplasia is one of the most important risk factors for malignant transformation, but the criteria used for grading are still a matter of debate. Therefore, the aim of the present study was to describe and analyze the clinical and histological characteristics from a series of oral potentially malignant disordersdiagnosed in a single Center in a 14-year period. The files of the Oral Pathology Laboratory, Dental School, Rio de Janeiro State University, were reviewed from 2005 to 2018 and all cases diagnosed as leukoplakia, leukoerythroplakia, erythroplakia and actinic cheilitis were selected. Clinical information was obtained from the laboratory forms provided with the specimens and 5μm HE-stained histological sections from all cases were reviewed for microscopical analysis, according with the criteria recommended by the World Health Organization. The final sample was composed by 953 lesions, affecting 534 females (56%) and 419 males (44%).Mean age was 59.7 years and 87.5% of the patients were 41 to 80 years-old. The most affected regions were the lower lip (20.1%), tongue (18.1%) and buccal mucosa (16.9%). Leukoplakias, actinic cheilitis, leukoerythroplakiasanderythroplakias represented, respectively, 74.6%, 15.2%, 9.3% and 0.8% of the sample. Mostcases presented no dysplasia (42.1%), and mild, moderate and severe dysplasia were found in, respectively, 33.5%, 14.6% and 9.9% of the cases. Lesions located in the tongue, floor of mouth and lower lip showed higher frequencies of moderate/intense epithelial dysplasias. Hyperparakeratosis was also more frequent in moderate/intense epithelial dysplasias. The most common histological criteria were the increase in number and size of nucleoli, loss of polarity of the basal cells, and variations in cellular size and shape. Classification by the binary system showed that 7% were high-risk lesions. The presence of superficial normal andabnormal mitotic figures seems to be an important additional criteria for diagnosis of epithelial dysplasia. In conclusion, all histological criteria used for diagnosis and grading of oral epithelial dysplasia showed increased frequency as grading increases. Some additional criteria, such as the presence of superficial normal and abnormal mitotic figuresand endophytic epithelial proliferation, seem to be useful in grading oral epithelial dysplasias.