The Mondini defect in Turner's syndrome. A temporal bone report.

The histopathology of the right temporal bone of a 47 year old deaf woman with Turner's Syndrome (gonadal dysgenesis) is described. The appearances are of the Mondini deformity, the cochlea consisting of a single basal turn with a bulbous apical dilatation. The organ of Corti was absent. The remainder of the bony labyrinth save for the cochlear aqueduct was normal. The patient's death was due to a cerebral astrocytoma. Previous reports concerning the co-existence of gonadal dysgenesis, congenital deafness and non-gonadal neoplasia are discussed.