Hypoglossal canal invasion by glomus jugulare tumors: clinico-radiological correlation

The aim of this retrospective study is to assess the rate at which glomus jugulare tumors invade the hypoglossal canal (HC) and to correlate computed tomography (CT) and magnetic resonance imaging (MRI) findings with the clinical evidence of cranial nerve (CN) XII dysfunction. CT and MRI imaging modalities of 31 patients were blindly reviewed by an attending neuroradiologist. Imaging studies identified involvement in 22 tumors (22/31, 71.0%). Thirteen of 22 patients (59.1%) had clinically evident CN XII symptoms. Accuracy rate was 76.7% (23/30) for MRI and 78.6% (11/14) for CT. MRI showed 100% sensitivity but had only 59% specificity and the specificity for CT was 66.7%. When radiologists elucidate HC involvement, it may alter the surgical approach and may lead to more focused/accurate clinical evaluation of tongue function.