Resumen La evaluación de la expresión del ligando 1 de muerte programada (PD-L1) es un criterio de elegibilidad para la inmunoterapia anti-PD-L1 en el carcinoma oral de células escamosas (COCE). También deben evaluarse otros componentes del microambiente tisular. Aquí se informaron cuatro casos de carcinoma de células escamosas orales. Se realizaron análisis histopatológicos del grado tumoral y TIL (infiltrado inflamatorio asociado a tumor) e inmunohistoquímica para CD4, CD8 y PD-L1. Los casos se clasificaron según el microambiente tisular en resistencia inmunitaria adaptativa, ignorancia inmunológica, tolerancia o inducción intrínseca. Este análisis destaca la importancia de comprender el microambiente inmunológico que puede presentar el COCE para la identificación de dianas terapéuticas más eficaces contra la enfermedad.

Abstract The evaluation of the expression of programmed cell death protein (PD-L1) is an eligibility criterion for anti-PD-L1 immunotherapy in oral squamous cell carcinoma (OSCC). Other components of tissue microenvironment should also be evaluated. Here, four cases of oral squamous cells carcinoma were reported. Histopathological analysis of tumor grade and TILs and immunohistochemistry for CD4, CD8, and PD-L1 was done. The cases were classified according to the tissue microenvironment in adaptive immune resistance, immunological ignorance, tolerance, or intrinsic induction. This analysis highlights the importance of understanding the immunological microenvironment that the OSCC can present for the identification of more effective therapeutic targets against the disease.

Keratoacanthoma (KA) is a self-limited benign epithelial proliferative lesion that eventually presents with very similar clinical features to squamous cell carcinoma. Many KA appear in the vermilion border of the lips and therefore dental professionals must be familiar of the disease. This article reports the case of a 40-year-old female patient presenting with an exophytic ulcerative tumor in her lower lip that resolved after incisional biopsy. Photographic documentation of the case is presented and topics that are relevant to the clinical management of the disease are addressed.

p53 alterations have been implicated in oral carcinogenesis process. Squamous cell carcinoma is the most common malignancy of the oral cavity, the tongue being the most frequent affected site. The aim of this study was to compare p53 immunoexpression in 43 samples of oral SCC from 5 different anatomical sites: tongue, floor of the mouth, alveolar ridge/gingiva, retromolar region and other regions of the oral cavity. Thirty-three lesions (76,8%) showed positivity for p53 (mean index of 48,37%). No statistically significant differences were found between p53 expression and the different oral sites analyzed. Similarly, no differences were found when comparing tongue lesions with the remaining sites. These results suggest that it might not exist any difference among oral cavity anatomical sites in relation to p53 immunoexpression. Moreover, mechanisms other than p53 alterations in squamous cell carcinomas of the tongue may be of relevance for the higher tumour aggressiveness found in this anatomical site

Las alteraciones de la p53 han sido implicadas en el proceso de carcinogénesis oral. El carcinoma de células escamosas es la malignidad más común de la cavidad oral, siendo la lengua el sitio afectado con mayor frecuencia. El objetivo de este estudio ha sido comparar la inmunoexpresión de la p53 en 43 muestras de carcinoma de células escamosas de la cavidad oral (CCEOs) de 5 sitios anatómicos distintos: lengua, piso bucal, encía/crista alveolar, región retromolar y otras regiones de la cavidad oral. Treinta y tres lesiones (el 76,8%) han mostrado positividad para la p53 (índice promedio del 48,37%). No han sido encontradas diferencias estadísticamente significantes entre la expresión de p53 y los diferentes sitios orales analizados. Similarmente, no han sido encontradas diferencias cuando comparadas las lesiones de lengua con los sitios remanentes. Estos resultados parecen sugerir la no existencia de diferencias entre los sitios anatómicos orales en cuanto a la inmunoexpresión de la p53. Además de eso, otros mecanismos, además de las alteraciones de la p53, en los CCEs de lengua, pueden tener relevancia en la mayor agresividad tumoral encontrada en este sitio anatómico en particular

Poucos estudos têm investigado a toxicidade tecidual local das tatuagens por amálgama (TA), embora diversos trabalhos demonstrem efeitos nocivos desse material restaurador. Pouco se sabe sobre a ativação de células inflamatórias nesse tipo de lesão. A reação tecidual contra os restos de amálgama varia com o tamanho das partículas implantadas. O antígeno leucocitário humano DR (HLA-DR) está associado com a ativação de células inflamatórias, sendo relacionado à apresentação de antígeno. Metalotioneínas (MT) são proteínas envolvidas com neutralização de metais pesados, tais como mercúrio e prata. O objetivo do presente trabalho foi investigar a imunolocalização de HLA-DR e MT em TA compostas por depósitos teciduais de diferentes tamanhos. Cortes histológicos de lesões fixadas em formol e embebidas em parafina foram submetidos a técnica imunoistoquímica para a detecção dos antígenos mencionados. Os resultados demonstraram denso infiltrado inflamatório associado com partículas grandes ou pulverizadas, observando-se presença de células HLA-DR e MT positivas. Paredes de vasos sangüíneos e fibras de tecido conjuntivo impregnadas por restos de amálgama foram negativas para HLA-DR, mas positivas para MT. Impregnação da membrana basal por partículas de amálgama correspondia a forte positividade para MT no epitélio. Esses resultados demonstram a existência de efeitos nocivos locais das TA sobre os tecidos.

Despite studies concerning toxic reactions related to amalgam components in the literature, few studies have been devoted to evaluate local noxious effects of amalgam tattoos (AT) on biological tissues. In addition, little is known about activation of inflammatory cells by mucosa-implanted amalgam debris. Tissue reaction to AT depends on the particle size. Human leukocyte antigen DR (HLA-DR) is an activation marker of inflammatory cells associated with antigen presentation. Metallothioneins (MT) are proteins involved with metal detoxication, including mercury and silver. The purpose of the present study was to investigate the immunolocalization of HLA-DR and MT in AT with large or powdered particles. Paraffin-embedded AT tissue blocks were sectioned and subjected to immunohistochemistry for HLA-DR and MT localization. The results demonstrated a dense mononuclear inflammatory infiltrate associated with large and powdered debris and positivity for HLA-DR and MT in inflammatory cells. While blood vessel walls and connective fibers impregnated with powdered particles were negative for HLA-DR, they were positive for MT. In addition, wherever epithelial basement membrane impregnation by powdered amalgam particles was observed, a strong positivity for MT was detected. These findings demonstrate that residual elements of AT still have noxious local effects over tissues.