Neurilemoma as a presenting feature of neurofibromatosis.

A previously healthy 38-year-old woman presented with gradually progressive ptosis and downward deviation of her left eye and a palpable left superonasal orbital mass. The mass was excised, and histopathologic examination revealed a tumor composed of spindle cells arranged in both Antoni A and B patterns. Presence of S-100 antigen was determined by immunoperoxidase staining. The diagnosis was neurilemoma. A right apical extraparenchymal mass detected on a preoperative chest roentgenogram and computed tomography was most consistent with a benign neurogenic tumor. The presentation was that of a recently discovered neurilemoma in a patient with preexisting, but previously undiagnosed, neurofibromatosis.