Teratoma of the middle ear: a real entity or a non-entity?

Space-occupying lesions of the middle ear range from wholly benign developmental anomalies to highly virulent and aggressive malignancies. Amongst the benign entities classed with the family of developmental anomalies, the middle ear choristoma is well known. But what of the middle ear teratoma? Recent reports suggest that, while rare, teratomas of the middle ear do exist. Middle ear teratomas are defined as tumors consisting of benign tissues derived from all three embryologic layers: endoderm, mesoderm and ectoderm. They are lesions of the neonatal period and early infancy. While complete surgical excision will be curative, a thorough histologic examination of the specimen is recommended to exclude the possibility of immature and/or frankly malignant elements being admixed with the benign teratomatous elements.