Mature teratoma of the middle ear

The authors report a case of mature teratoma of the middle ear in a 3-year-old girl with a 1-year history of otitis media. Radiologic investigation revealed a partially cystic lesion of the petrous portion of the right temporal bone. It produced opacification of the middle ear as well as destruction of septal air cells. The patient underwent a subtotal petrosectomy. Histologically, the tumor was composed of an intimate admixture of mature tissues representing all three germ layers, including brain, myelinated nerve trunks, skeletal muscle, bone, immature cartilage, seromucinous glands, and respiratory epithelium. Of note within the brain tissue was choroid plexus within an ependyma-lined rudimentary ventricle. Immunohistochemical studies were also performed. Twenty months after surgery, the patient was well, with complete recovery from symptoms. Teratomas of the middle ear are rare neoplasms. Only a few examples have been reported. As a rule, they are cured by resection and do not require adjuvant therapy.