Skin metastases in metastatic uveal melanoma: GNAQ/GNA11 mutational analysis as a valuable tool.

BACKGROUND: Uveal melanomas represent 3.1% of all melanomas, with a high potential of metastatic disease of up to 50%, where the median survival time is 6 months. Though liver metastases dominate as the primary site for metastasis, the existence of primary skin metastases is still under discussion but has been reported in only a few studies. OBJECTIVES: We present two cases in which patients with a known history of uveal melanoma developed melanoma skin metastases. METHODS: Mutational analysis was performed to clarify the origin of the metastases (uvea or skin). RESULTS: The analyses revealed GNA11 mutations, which are typical for uveal melanoma. These cases strongly suggest the skin to be the primary site of uveal melanoma. CONCLUSIONS: Knowledge about the mutational status of uveal melanomas opens the opportunity for future targeted therapies that directly interact with the mutation and its activated signal cascades. First trials in uveal melanoma have shown promising results with MEK inhibitors.