Labyrinthine sequestrum (a case report).

An unusual case of a labyrinthine sequestrum is presented. During mastoidectomy on a patient with chronic recurrent mastoiditis, a large sequestrum in the labyrinth was found. Four years earlier he had been treated for a posterior fossa abscess, which had followed acute otitis media. An extensive ablative and drainage procedure of the pars superior and pars inferior with preservation of the facial nerve was indicated in this patient.