Echographic characteristics of benign orbital schwannomas (neurilemomas)

We examined two patients with orbital schwannomas (neurilemomas). The echographic findings, including a sharply outlined capsule, a well-defined central cystic space within the tumor with very low internal reflectivity surrounded by smaller cysts with variable reflectivity, slight or no compressibility, and blood flow, should help to differentiate these benign tumors from other orbital lesions. Histologic examination showed a combination of Antoni type A (dense and cellular) and Antoni type B (loose, edematous, or necrotic) patterns.