The association of oral lichen planus (OLP) lesions with malignant transformation risk has remained a controversial topic and is of clinical importance. Therefore, the present study evaluated the expression levels of p16, Ki-67, budding uninhibited by benzimidazoles 3 (Bub-3) and sex-determining region Y-related high mobility group box 4 (SOX4), and their roles as precancerous biomarkers in OLP. A retrospective study was performed, in which tissue blocks of OLP, oral dysplasia (OD), cutaneous lichen planus (CLP) and oral fibrous hyperplasia (OFH) were used (n=120). A positivity index (PI) for p16, BUB3, Ki-67 and SOX4 expression was calculated in each group. The PI for p16 was 20.65% for OLP, 7.85% for OD, 86.59% for CLP and 11.8% for OFH, and the difference between these groups was statistically significant (P<0.001). PIs of Ki-67 were indicated as 11.6% for OLP, 14.4% for OD, 8.24% for CLP and 5.5% for OFH, and a statistically significant difference was observed between the groups (P<0.001). Notably, the expression levels of BUB3 were not statistically different among groups. The highest expression levels of SOX4 were identified in CLP (P<0.001 vs. OLP/CLP; P=0,001 vs. CLP/OD). The determined expression levels of p16 and Ki-67 suggest that specific OLP lesions may have an intermediate malignant potential and should be carefully followed up. The intense SOX4 staining in CLP indicated a different proliferation pattern of epithelium compared with oral mucosa cells. These findings suggest that SOX4 expression may also be associated with the different clinical courses of OLP and CLP.

Oral lichen planus (OLP) represents a common mucocutaneous disease. Various authors have suggested that OLP has malignant potential; however, the mechanisms involved in malignant transformation have not yet been elucidated. A 79-year-old man presented a white lesion for five months in the buccal mucosa diagnosed as OLP. After two months using 0.05% clobetasol ointment for treatment, the lesion became ulcerated. A new biopsy of the same lesion was performed, and histological analysis showed an in situ oral carcinoma (ISOC). An immunohistochemistry panel was performed, and p16 expression was negative in OLP, however, it showed weak cytoplasmic staining in ISOC. There was strong nuclear BUB3 staining in both OLP and ISOC areas. p53 showed less intense nuclear staining in both regions. Ki67 was negative in OLP area, but showed nuclear staining in the ISOC. SOX4 was negative in both studied areas. BUB3 expression, first reported in this case, and the p16 expression may suggest some influence of these genes on pathogenesis or malignant potential of OLP.

No abstract

RESUMOO xantoma verruciforme é uma lesão rara de etiologia não determinada, que acomete, principalmente, a mucosa oral. Na maioria das vezes é assintomática, caracterizando-se por uma elevação bem-delimitada, de superfície rugosa ou papilar, e sua principal localização na boca é a gengiva. Com relação ao tamanho, a maioria das lesões não ultrapassa 2 cm no seu maior diâmetro. O objetivo do presente trabalho é relatar um caso raro de extenso xantoma verruciforme em paciente do gênero masculino, de 55 anos, apresentando lesão localizada no palato duro e na gengiva palatina. Clinicamente, a lesão possuía bordas bem-destacadas, de superfície levemente granular e coloração avermelhada, com consistência elástica, medindo aproximadamente 2,8 X 1,5cm. O exame histopatológico demonstrou a presença de proliferação do epitélio de revestimento, exibindo papilomatose, paraceratose e alongamento das cristas epiteliais. Na lâmina própria, células xantomatosas com citoplasma claro e vacuolado puderam ser observadas. O paciente encontra-se livre de recidivas após 18 meses de acompanhamento clínico. De acordo com extensa pesquisa em bases de dados (pubmed, medline, lilacs), o presente caso representa uma das maiores lesões do tipo xantoma verruciforme já relatadas na literatura.Termos de indexação: Mucosa bucal. Palato. Patologia bucal. Xantomatose.

No abstract