Immunoexpression of PD-L1, CD4+ and CD8+ cell infiltrates and tumor-infiltrating lymphocytes (TILs) in the microenvironment of actinic cheilitis and lower lip squamous cell carcinoma.

OBJECTIVE: Lower lip squamous cell carcinomas (LLSCC) could be associated with a previous history of potentially malignant oral diseases (PMOD), especially actinic cheilitis (AC), with high sun exposure being a well-described risk factor. Immune evasion mechanisms, such as the PD-1/PD-L1 (programmed cell death protein 1/programmed death-ligand 1) pathway has been gaining prominence since immunotherapy with immune checkpoint inhibitors showed a positive effect on the survival of patients with different types of neoplasms. Concomitant with the characterization of the tumor microenvironment, the expression of either or both PD-1 and PD-L1 molecules may estimate mutual relations of progression or regression of the carcinoma and prognostic values of the patient.Considering the importance of tumor microenvironment characterization, this study aims to determine the immunoexpression of PD-L1 and correlate with the frequency of CD4+ and CD8+ cells in AC and LLSCC lesions and with tumor-infiltrating lymphocytes (TILs) in LLSCC and its relationship with histopathological characteristics. METHODOLOGY: This sample includes 33 cases of AC and 17 cases of LLSCC. The cases were submitted to histopathological analysis and to CD4+, CD8+, and PD-L1+ cell determination by immunohistochemistry. RESULTS: There was a significant difference among the frequencies of CD4+, CD8+, and PD-L1+ cells between AC and LSCC cases, higher in the last group. Moreover, histopathological and atypical changes in AC and LLSCC were correlated with the frequencies of PD-L1+, CD4+, and CD8+ cells. In AC, PD-L1+ cases had a low frequency of CD4+ cells, but on the other hand, PD-L1+ cases of LLSCC had a higher frequency of CD4+ and CD8+ cells. CONCLUSION: Therefore, the PD-L1 molecule may be a potential escape route for the immune response in oral lesions, but the mechanisms differ between AC and LLSCC. Future studies related to immune evasion and immunotherapy in oral lesions should consider the analysis of inflammatory infiltrate and TILs.

Immunoexpression of PD-L1, CD4+ and CD8+ cell infiltrates and tumor-infiltrating lymphocytes (TILs) in the microenvironment of actinic cheilitis and lower lip squamous cell carcinoma

Abstract Lower lip squamous cell carcinomas (LLSCC) could be associated with a previous history of potentially malignant oral diseases (PMOD), especially actinic cheilitis (AC), with high sun exposure being a well-described risk factor. Immune evasion mechanisms, such as the PD-1/PD-L1 (programmed cell death protein 1/programmed death-ligand 1) pathway has been gaining prominence since immunotherapy with immune checkpoint inhibitors showed a positive effect on the survival of patients with different types of neoplasms. Concomitant with the characterization of the tumor microenvironment, the expression of either or both PD-1 and PD-L1 molecules may estimate mutual relations of progression or regression of the carcinoma and prognostic values of the patient. Objective: Considering the importance of tumor microenvironment characterization, this study aims to determine the immunoexpression of PD-L1 and correlate with the frequency of CD4+ and CD8+ cells in AC and LLSCC lesions and with tumor-infiltrating lymphocytes (TILs) in LLSCC and its relationship with histopathological characteristics. Methodology: This sample includes 33 cases of AC and 17 cases of LLSCC. The cases were submitted to histopathological analysis and to CD4+, CD8+, and PD-L1+ cell determination by immunohistochemistry. Results: There was a significant difference among the frequencies of CD4+, CD8+, and PD-L1+ cells between AC and LSCC cases, higher in the last group. Moreover, histopathological and atypical changes in AC and LLSCC were correlated with the frequencies of PD-L1+, CD4+, and CD8+ cells. In AC, PD-L1+ cases had a low frequency of CD4+ cells, but on the other hand, PD-L1+ cases of LLSCC had a higher frequency of CD4+ and CD8+ cells. Conclusion: Therefore, the PD-L1 molecule may be a potential escape route for the immune response in oral lesions, but the mechanisms differ between AC and LLSCC. Future studies related to immune evasion and immunotherapy in oral lesions should consider the analysis of inflammatory infiltrate and TILs.

ORAL HAIRY POLYP IN A TEENAGER: CASE REPORT AND LITERATURE REVIEW.

OBJECTIVE: To report an unusual case of oral hairy polyp (HP) and review the literature, providing epidemiological, clinical and histopathological information on this disease. CASE DESCRIPTION: A 12-year-old male patient was referred to a Stomatology department with a nodule in the posterior midline of the tongue. The patient did not know exactly when it arose or whether it had grown since then. Clinical exam revealed a bulky and mobile pedunculated mass lesion on the dorsum of the tongue, with a diameter of approximately 1 cm. The patient's mother reported no previous health problem. An excisional biopsy was performed, the surgical specimen was sent for anatomopathological analysis, and the findings were compatible with the diagnosis of HP. COMMENTS: Hairy polyp is a rare lesion, especially in the oral region. The literature search revealed only 10 case reports of oral HP published between January 1999 and January 2019, and they revealed a predominance of the disease in female newborns. Two uncommon facts were presented in this case: the patient was male and diagnosis was made at 12 years old.

Oral hairy polyp in a teenager: case report and literature review / Pólipo piloso oral em um adolescente: relato de caso e revisão de literatura

ABSTRACT Objective: To report an unusual case of oral hairy polyp (HP) and review the literature, providing epidemiological, clinical and histopathological information on this disease. Case description: A 12-year-old male patient was referred to a Stomatology department with a nodule in the posterior midline of the tongue. The patient did not know exactly when it arose or whether it had grown since then. Clinical exam revealed a bulky and mobile pedunculated mass lesion on the dorsum of the tongue, with a diameter of approximately 1 cm. The patient's mother reported no previous health problem. An excisional biopsy was performed, the surgical specimen was sent for anatomopathological analysis, and the findings were compatible with the diagnosis of HP. Comments: Hairy polyp is a rare lesion, especially in the oral region. The literature search revealed only 10 case reports of oral HP published between January 1999 and January 2019, and they revealed a predominance of the disease in female newborns. Two uncommon facts were presented in this case: the patient was male and diagnosis was made at 12 years old.

RESUMO Objetivo: Relatar um caso incomum de pólipo piloso (PP) oral e revisar a literatura para trazer informações epidemiológicas, clínicas e histopatológicas acerca da doença. Descrição do caso: Paciente do sexo masculino, 12 anos de idade, encaminhado ao Departamento de Estomatologia com nódulo na região posterior de linha média da língua. O paciente não soube relatar quando surgiu a lesão e se ela havia crescido desde então. O exame clínico revelou massa pedunculada, volumosa e móvel no dorso da língua, medindo aproximadamente 1,0 cm de diâmetro. A mãe do paciente relatou que ele nunca havia tido nenhum problema de saúde anterior. Foi realizada biópsia excisional e o material foi enviado para análise anatomopatológica, sendo os achados compatíveis com o diagnóstico de PP. Comentários: O pólipo piloso é uma lesão rara, especialmente na região oral. A pesquisa bibliográfica revelou apenas dez relatos de casos de PP oral, publicados entre janeiro de 1999 e janeiro de 2019, sendo observada predominância da doença em recém-nascidos do sexo feminino. Dois fatos incomuns ocorreram neste caso: tratava-se de um paciente do sexo masculino e o diagnóstico se deu aos 12 anos de idade.