Paraganglioma of the hypoglossal nerve.

After the incidental intraoperative discovery of a paraganglioma of cranial nerve XII, we searched our hospital database and literature for similar cases to determine whether evidence exists to support the existence of paraganglioma of the hypoglossal nerve. We describe a case of cranial nerve XII paraganglioma, recognized only during surgery, without any indicative preoperative sign or symptom nor diagnostic imaging studies. In light of published findings, only four cases described since 1966, and our experience, the report discusses diagnostic criteria that could aid in establishing a diagnosis of hypoglossal nerve paraganglioma based on a reasonable degree of medical certainty.