Fluid-fluid levels in benign neurogenic tumors.

We report two cases of cystic lesions in the head and neck, one a cystic schwannoma and the other a neurofibroma, both of which showed fluid-fluid levels on MR images. The differential diagnosis of fluid-fluid levels in the head and neck region should include cystic hygromas, aneurysmal bone cysts, soft-tissue cavernous hemangiomas, and simple bone cysts.