Magnetic Resonance Imaging Features of Schwannoma of the Sinonasal Tract.

Purpose The purpose of the study was to explore the characteristic magnetic resonance imaging (MRI) findings of schwannoma of the sinonasal tract. Methods Eighteen patients with histopathologically confirmed sinonasal schwannoma underwent conventional MRI, and 12 had dynamic contrast-enhanced MRI studies synchronously. The morphology feature, signal intensity, enhancement degree, and time intensity curve (TIC) pattern of schwannomas were retrospectively analyzed. Results This entity appeared as a well-circumscribed, oval or fusiform soft tissue mass with a mean greatest diameter of 38 mm. Schwannomas exhibited isointense on T1-weighted image in 12 patients and hypointense in 6. On T2-weighted image, the lesions were heterogeneously isointense in 14 patients and hyperintense in 4. The lesions had heterogeneously moderate and marked contrast enhancement in 2 and 16, respectively. The mottled-, island-, and multicyst-like appearance were identified in 3, 4, and 11, respectively. Compared with inverted papilloma and lobular capillary hemangioma, the type I TIC is characteristic of schwannoma. Conclusions A well-circumscribed mass displaying T2 intermediate signal intensity, marked enhancement, and type I TIC, with cystic changes, strongly suggests the diagnosis of sinonasal schwannoma.