Uveal melanoma: evaluation of extrascleral extension using thin-section MR of the eye with surface coils

PURPOSE: This study was done to evaluate the role of high-resolution magnetic resonance (MR) imaging with special surface coils in selecting the correct therapeutic approach (eye enucleation or follow-up) in patients with suspected extrascleral extension of uveal melanoma. MATERIALS AND METHODS: This prospective study involved 12 patients with suspected extrascleral extension of uveal melanoma on orbital ultrasonography. All patients were studied with thin-section MR imaging of the eye using surface coils. RESULTS: High-resolution MR imaging of the eye excluded extrascleral extension of disease in 8/12 patients: in 4/8 cases it revealed vascular ectasia and in the other 4/8 cases the linear hypointensity of the sclera was unbroken. Seven of these eight patients were followed up by ultrasound, which showed stability of melanoma for at least 2 years, while the last patient underwent enucleation, and the histological examination confirmed the MR diagnosis. In 4/12 patients, high-resolution MR suggested a diagnosis of extrascleral extension of melanoma, which was confirmed at histological examination after enucleation. CONCLUSION: High-resolution MR imaging of the eye with surface coils allowed us to evaluate extrascleral extension of uveal melanoma and choose the correct therapeutic approach, avoiding unnecessary enucleation in 7/12 patients.