Malignant transformation of a choroidal nevus 6 years after brachytherapy of a non-contiguous choroidal melanoma - a case report and review of literature

Background: Brachytherapy is a well established procedure for treatment of malignant choroidal processes. Approximately 5% of the cases, will show loc al recurrences within 6 years. We report a patient who has developed a mali gnant transformation of an uveal nevus following brachytherapy of a non-con tiguous uveal melanoma. In addition, we reviewed the literature concerning similar cases. History and signs: In 1991 a Ruthenium application was performed on a 65-ye ar old patient suffering of an equatorial malignant choroidal melanoma. At that time, a nevus at the posterior pole was present. From 1997 to 1998 the nevus continuously increased in size. Visual acuity decreased and a retina l detachment developed. Combining the clinical and the sonographic findings , the diagnosis of a malignant melanoma arising of a nevus was established. Enucleation was performed in 1998. Therapy and outcome: Histologic examination revealed the diagnosis of an ep ithelioid-cell-type malignant uveal melanoma arising in a nevus. Till now, the patient is free of metastatic disease. Conclusion: Non-contiguous development of uveal melanomas in the same eye a re extremely rare. We could identify in the literature 5 cases of non-conti guous melanomas following brachytherapy of an uveal melanoma. In none of th ese cases, the secondary melanoma has arisen in a nevus. Follow-up examinat ion of patients with uveal melanoma treated with brachytherapy should inclu de not only examination of the treated area, but also the whole fundus of t he eye in order to recognize secondary tumours as early as possible.