Ciliary body neurilemoma. Unusual clinical findings intimating the diagnosis

Neurilemomas (schwannomas) rarely occur intraocularly. When present, they pose a diagnostic dilemma for the physician and often are mistaken as a malignant lesion, resulting in enucleation.

The authors report the clinical findings of a 46-year-old man with a slowly progressive growing mass of the anterior chamber, associated with glaucoma and the development of cataract. To further delineate the tumor's features, ancillary techniques, including ultrasonography, computed tomography, and magnetic resonance imaging, were conducted. A definitive anterior chamber biopsy of the tumor was performed with histologic examination and electron microscopy.

Ultrasonography, high-resolution computed tomography and magnetic resonance imaging showed a well-delineated mass of the inferior ciliary body involving nearly 5 clock hours of the angle. Two clinical features that suggested a longstanding tumor were brilliant transillumination of the mass (leading to the impression of a "cystic mass," not corroborated by ultrasonography) and retrodisplacement of the involved iris root. The histology, and particularly the electron microscopic features, confirmed the diagnosis of a neurilemoma, a benign tumor of the anterior segment.

Intraocular neurilemomas are extremely rare tumors. Few are well documented with modern ancillary techniques. Clinical findings in conjunction with radiographic and ultrasonic features may support the diagnosis of a benign tumor. For this patient, confirmation via biopsy permitted combined cataract and glaucoma surgery to rehabilitate the eye, which retains 20/20 visual acuity 3 years after the procedure.