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

Abstract

Brachytherapy is a well established procedure for treatment of malignant choroidal processes. Approximately 5 % of the cases, will show local recurrences within 6 years. We report a patient who has developed a malignant transformation of an uveal nevus following brachytherapy of a non-contiguous uveal melanoma. In addition, we reviewed the literature concerning similar cases. In 1991 a Ruthenium application was performed on a 65-year 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 retinal 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. Histologic examination revealed the diagnosis of an epithelioid-cell-type malignant uveal melanoma arising in a nevus. Till now, the patient is free of metastatic disease. Non-contiguous development of uveal melanomas in the same eye are extremely rare. We could identify in the literature 5 cases of non-contiguous melanomas following brachytherapy of an uveal melanoma. In none of these cases, the secondary melanoma has arisen in a nevus. Follow-up examination of patients with uveal melanoma treated with brachytherapy should include not only examination of the treated area, but also the whole fundus of the eye in order to recognize secondary tumours as early as possible.