[Tumour of the endolymphatic sac in a 12-year-old child].

We present the case of a 12-year-old boy with right-sided pantonal sensorineural hearing loss. With the help of imaging diagnostics a tumour of the right temporal bone was detected. It was resected using a transmastoid approach. Histopathological study showed a low-grade adenocarcinoma of the endolymphatic sac, known as Heffner tumour. An association with the von-Hippel-Lindau complex - as often reported in the medical literature - could not be proven.