Fibrous dysplasia: rare manifestation in the temporal bone / Displasia fibrosa: manifestação rara no osso temporal

Abstract Introduction: Fibrous dysplasia is a benign disorder, in which normal bone is replaced by fibrosis and immature bone trabeculae, showing a similar distribution between the genders, and being more prevalent in the earlier decades of life. Fibrous dysplasia of the temporal bone is a rare condition, and there is no consensus as to whether it is more common in monostotic or polyostotic forms. External auditory meatus stenosis and conductive dysacusis are the most common manifestations, with cholesteatoma being a common complication, whereas the involvement of the otic capsule is an unusual one. Surgical treatment is indicated to control pain or dysacusis, otorrhea, cholesteatoma, and deformity. Objectives: To describe the clinical experience of a tertiary referral hospital with cases of fibrous dysplasia of the temporal bone. Methods: Sampling of patients diagnosed with fibrous dysplasia of the temporal bone, confirmed by tomography, treated at the pediatric otology and otorhinolaryngology outpatient clinics, between 2015 and 2018. The assessed variables were age, gender, laterality, external auditory meatus stenosis, deformity, hearing loss, presence of secondary cholesteatoma of the external auditory meatus, lesion extension and management. Results: Five patients were included, four females and one male, with age ranging from 13 to 34 years. Three had the polyostotic form and two the monostotic form of fibrous dysplasia of the temporal bone. Four patients had local deformity and external auditory meatus stenosis, two of which progressed to cholesteatoma. All patients showed some degree of hearing impairment. All had preserved otic capsule at the tomography. Two patients are currently undergoing clinical observation; two were submitted to tympanomastoidectomy due to secondary cholesteatoma; one was submitted to lesion resection, aiming to control the dysacusis progression. Conclusion: Five cases of fibrous dysplasia of the temporal bone were described, a rare disorder of which the otologist should be aware.

Resumo Introdução: Displasia fibrosa é uma desordem benigna, na qual o osso é substituído por fibrose e trabeculado ósseo imaturo, com distribuição semelhante entre sexos, mais comum nas primeiras décadas de vida. O acometimento do osso temporal pela displasia fibrosa é raro, não há consenso se é mais comum nas formas monostóticas ou poliostóticas. Estenose do meato acústico externo e disacusia condutiva são as manifestações mais comuns. Colesteatoma é também uma complicação comum e o acometimento da cápsula ótica incomum. O tratamento cirúrgico está indicado para controle de dor ou disacusia, otorreia, colesteatoma, deformidade. Objetivos: Descrever a experiência clínica de hospital terciário de referência com casos de displasia fibrosa do osso temporal. Método: Amostragem dos pacientes com diagnóstico de displasia fibrosa do osso temporal, confirmado pela tomografia, atendidos nos ambulatórios de otologia e otorrinolaringologia pediátrica, entre 2015 e 2018. As variáveis avaliadas foram idade, gênero, lateralidade, estenose do meato acústico externo, deformidade, perda auditiva, presença de colesteatoma secundário de meato acústico externo, extensão da lesão e conduta adotada. Resultados: Foram incluídos cinco pacientes, quatro do sexo feminino e um masculino, de 13-34 anos. Três apresentaram a forma poliostótica da displasia fibrosa do osso temporal e dois a forma monostótica. Quatro apresentaram deformidade local e estenose do meato acústico externo, dois desses evoluíram com colesteatoma. Todos manifestaram algum grau de comprometimento auditivo. Todos apresentaram cápsula ótica preservada na tomografia. Duas pacientes estão em observação clínica; duas foram submetidas a timpanomastoidectomia devido a colesteatoma secundário; um foi submetido a ressecção da lesão para controle de progressão da disacusia. Conclusão: Foram descritos cinco casos de displasia fibrosa do osso temporal, desordem rara para a qual o otologista deve estar atento.

Fibrous dysplasia: rare manifestation in the temporal bone.

INTRODUCTION: Fibrous dysplasia is a benign disorder, in which normal bone is replaced by fibrosis and immature bone trabeculae, showing a similar distribution between the genders, and being more prevalent in the earlier decades of life. Fibrous dysplasia of the temporal bone is a rare condition, and there is no consensus as to whether it is more common in monostotic or polyostotic forms. External auditory meatus stenosis and conductive dysacusis are the most common manifestations, with cholesteatoma being a common complication, whereas the involvement of the otic capsule is an unusual one. Surgical treatment is indicated to control pain or dysacusis, otorrhea, cholesteatoma, and deformity. OBJECTIVES: To describe the clinical experience of a tertiary referral hospital with cases of fibrous dysplasia of the temporal bone. METHODS: Sampling of patients diagnosed with fibrous dysplasia of the temporal bone, confirmed by tomography, treated at the pediatric otology and otorhinolaryngology outpatient clinics, between 2015 and 2018. The assessed variables were age, gender, laterality, external auditory meatus stenosis, deformity, hearing loss, presence of secondary cholesteatoma of the external auditory meatus, lesion extension and management. RESULTS: Five patients were included, four females and one male, with age ranging from 13 to 34 years. Three had the polyostotic form and two the monostotic form of fibrous dysplasia of the temporal bone. Four patients had local deformity and external auditory meatus stenosis, two of which progressed to cholesteatoma. All patients showed some degree of hearing impairment. All had preserved otic capsule at the tomography. Two patients are currently undergoing clinical observation; two were submitted to tympanomastoidectomy due to secondary cholesteatoma; one was submitted to lesion resection, aiming to control the dysacusis progression. CONCLUSION: Five cases of fibrous dysplasia of the temporal bone were described, a rare disorder of which the otologist should be aware.