舌根部神経鞘腫の2症例

CTとMRIの所見を中心として

抄録

Neurilemmoma of the tongue base is rare. It is difficult to diagnose it early because of its anatomical situation, and biopsy may be inadequate because of the thick capsule. Recent advances in radiology are relatively helpful in the diagnosis of neurilemmoma. This report describes two patients with neurilemmoma of the tongue base examined by CT (computed tomography) and MRI (magnetic resonance imaging).
A large mass of the tongue base was found in a 49-year-old male and a 59-year-old female. Neurogenic tumors were diagnosed by CT and MRI. CT revealed a well-circumscribed mass in the medial portion of the tongue base. The mass was inhomogeneous on enhanced CT, suggesting neurilemmoma. On MRI, the mass was isointense with surrounding muscle tissue on T₁ weighted images and hyperintense on T₂ weighted images. With Gd-DTPA enhanced MRI the radiological diagnosis of neurilemmoma was clearly improved. MRI is not degraded by dental amalgam, and provides three-dimensional images.
Total removal of the mass was performed through a cervical approach in both patients, and neurilemmoma was diagnosed histopathologically.