Cartinoid tumor of the middle ear and mastoid.

Primary cartinoid tumors in the middle ear and mastoid are rare. They are also very difficult to distinguish from adenomas and adenocarcinomas, using conventional histological stains. We present clinical, histological, immunohistochemical and ultrastructural findings of a cartinoid tumor in the middle ear and mastoid in a 40-year-old male. A soft tumor was revealed in the posterior mesotympanum and mastoid cavity, and a radical tympanomastoidectomy was performed. The tumor cells were stained by chromogranin A, and neurosecretory granules were confirmed with electron microscopy. We also review 20 previously reported cases in regard to their presentation, symptoms, signs, tumor extension, treatments, and histopathology.