Sinonasal inverted papilloma: rate of recurrence and malignant transformation in 44 operated patients / Papiloma invertido nasossinusal: taxa de recorrência e transformação maligna em 44 pacientes operados

Abstract Introduction: Although sinonasal inverted papillomas are benign lesions, they are locally aggressive and have a potential malignant transformation ranging from 5% to 15%, with a high recurrence rate. Objective: The aim of this article is to describe the rate of recurrence and malignant transformation in patients with a diagnosis of inverted papilloma who underwent surgery in a tertiary hospital in São Paulo. Methods: We performed a retrospective analysis of patients diagnosed with sinonasal papilloma who had undergone surgery in a tertiary hospital in São Paulo, between August 1998 and August 2017. A patient chart review was conducted to assess data of patients' demographics, tumors characteristics, follow-up appointments, recurrence and malignancy. Inverted papillomas were analyzed and classified under the Krouse staging system. Results: A total of 69 surgeries were performed in patients with diagnosis of sinonasal papilloma. Inverted papilloma was the most prevalent subtype (49 cases ‒ 80.33%), followed by exophytic papilloma (6 cases ‒ 9.84%) and by oncocytic papilloma (6 cases - 9.84%). The recurrence rate was 34.09% for inverted papilloma (15/44) and the mean time of recurrence was 24.6 months. Malignant transformation occurred in 6 patients (13.64%). Three of these patients presented carcinoma in the first surgery and three patients developed carcinoma during the follow-up. Conclusion: The high recurrence rate and malignancy potential allow us to consider inverted papillomas as aggressive tumors. In a tertiary hospital in São Paulo the recurrence rate the mean time to recurrence is 24.6 months. The recurrence after 10 years implies was 34.09% and the need for long-term follow up. It is possible that the high recurrence rate and the high malignant transformation rate we found are due to the large number of tumors discovered at an advanced stage (most of them staged T3 and T4), secondary to poor access to health system, in developing countries.

Resumo Introdução: Embora os papilomas invertidos nasossinusais sejam lesões benignas, eles são localmente agressivos e apresentam uma potencial transformação maligna que varia de 5% a 15%, com alta taxa de recorrência. Objetivo: Descrever a taxa de recorrência e transformação maligna em pacientes com diagnóstico de papiloma invertido submetidos à cirurgia em um hospital terciário em São Paulo. Método: Análise retrospectiva dos pacientes diagnosticados com papiloma nasossinusal submetidos a cirurgia em um hospital terciário em São Paulo, entre agosto de 1998 e agosto de 2017. Uma revisão de prontuários dos pacientes foi realizada para avaliar dados demográficos, características dos tumores, consultas de seguimento, recorrência e malignidade. Os papilomas invertidos foram analisados e classificados de acordo com o sistema de estadiamento de Krouse. Resultados: Foram realizadas 69 cirurgias em pacientes com diagnóstico de papiloma nasossinusal. O papiloma invertido foi o subtipo mais prevalente (49 casos - 80,33%), seguido pelo papiloma exofítico (6 casos - 9,84%) e pelo papiloma oncocítico (6 casos - 9,84%). A taxa de recidiva foi de 34,09% para o papiloma invertido (15/44) e o tempo médio de recorrência foi de 24,6 meses. Transformação maligna ocorreu em seis pacientes (13,64%); três desses pacientes apresentaram carcinoma na primeira cirurgia e três pacientes desenvolveram carcinoma durante o seguimento. Conclusão: A alta taxa de recorrência e o potencial de malignidade nos permitem considerar os papilomas invertidos como tumores agressivos. Em um hospital terciário de São Paulo, a taxa de recorrência foi de 34,09% e o tempo médio de recorrência de 24,6 meses. A recorrência após 10 anos implica na necessidade de acompanhamento a longo prazo. É possível que a alta taxa de recorrência e a alta taxa de transformação maligna que encontramos sejam devidas à grande extensão dos tumores (a maioria deles nos estágios T3 e T4), decorrente do acesso precário ao sistema de saúde nos países em desenvolvimento.

Sinonasal inverted papilloma: rate of recurrence and malignant transformation in 44 operated patients.

INTRODUCTION: Although sinonasal inverted papillomas are benign lesions, they are locally aggressive and have a potential malignant transformation ranging from 5% to 15%, with a high recurrence rate. OBJECTIVE: The aim of this article is to describe the rate of recurrence and malignant transformation in patients with a diagnosis of inverted papilloma who underwent surgery in a tertiary hospital in São Paulo. METHODS: We performed a retrospective analysis of patients diagnosed with sinonasal papilloma who had undergone surgery in a tertiary hospital in São Paulo, between August 1998 and August 2017. A patient chart review was conducted to assess data of patients' demographics, tumors characteristics, follow-up appointments, recurrence and malignancy. Inverted papillomas were analyzed and classified under the Krouse staging system. RESULTS: A total of 69 surgeries were performed in patients with diagnosis of sinonasal papilloma. Inverted papilloma was the most prevalent subtype (49 cases ‒ 80.33%), followed by exophytic papilloma (6 cases ‒ 9.84%) and by oncocytic papilloma (6 cases - 9.84%). The recurrence rate was 34.09% for inverted papilloma (15/44) and the mean time of recurrence was 24.6 months. Malignant transformation occurred in 6 patients (13.64%). Three of these patients presented carcinoma in the first surgery and three patients developed carcinoma during the follow-up. CONCLUSION: The high recurrence rate and malignancy potential allow us to consider inverted papillomas as aggressive tumors. In a tertiary hospital in São Paulo the recurrence rate the mean time to recurrence is 24.6 months. The recurrence after 10 years implies was 34.09% and the need for long-term follow up. It is possible that the high recurrence rate and the high malignant transformation rate we found are due to the large number of tumors discovered at an advanced stage (most of them staged T3 and T4), secondary to poor access to health system, in developing countries.