Definitive diagnosis of pediatric Langerhans cell histiocytosis based on biopsy findings of the mastoid antrum: A case report

Abstract

Langerhans cell histiocytosis (LCH) is a disease in which Langerhans cells proliferate and cause tissue damage. Herein, we report our experience with a case in which it was difficult to treat refractory bilateral otitis externa, and subsequently, LCH was diagnosed based on biopsy findings of the mastoid antrum. The patient was a 1-year-old boy in whom the diagnosis was not possible by biopsy from the external auditory canal on an outpatient basis; however, a definitive diagnosis of LCH was possible by biopsy of the mastoid antrum. The reason why a biopsy from the external auditory canal was not helpful in the diagnosis of LCH is possibly explained by the fact that necrotic tissues (a secondary change of LCH occurring in the temporal bone) were used as biopsy specimen. Because many necrotic tissues were also found in the biopsy specimen of the mastoid antrum, immunostaining of the tumorous tissue was difficult. LCH must be considered in cases of refractory otitis externa. During biopsy, samples must be collected directly from the lesions and submitted for immunostaining.