Solitary Metastases Presentation from Uveal Melanoma: Report of 3 Cases and a Comprehensive Review of the Literature.

Introduction: Uveal melanoma (UM) is a rare condition accounting for only 5% of all primary melanoma cases. Still, it is the most frequently diagnosed primary intraocular malignant tumor in adults. UM is an aggressive malignancy that originates from melanocytes in the eye. UMs are usually initiated by a mutation in GNAQ or GNA11, and rarely harbor a BRAF or NRAS mutations like cutaneous melanomas. Even if the primary tumor has been successfully treated with radiation or surgery, up to half of all UM patients will eventually develop metastatic disease. The liver is the most frequent metastatic site, and solitary metastases are rare, especially without hepatic or other organs (such as lung or skin/soft tissue) involvement. Most of treatment options to the metastatic UM are still inadequate in preventing a fatal outcome.

Methods: A chart review of patients diagnosed with UM between January 1998 and December 2018 at the Instituto Português de Oncologia de Lisboa Francisco Gentil was performed.

Results: Three patients with solitary metastases several years after primary UV treatment without any other organ involvement were identified. Patient 1 and 2 showed a very long overall survival and progression-free survival after complete surgical removal of the isolated metastatic lesion from colon and spleen, respectively. The third patient presented with a single brain metastasis from choroidal melanoma harboring the BRAF V600E mutation, a condition rarely reported in UM.

Discussion: The cases highlight long relapse-free survival of UM; hence, a regular long-term follow-up should be mandatory. In addition, solitary metastases from UM should be treated, whenever possible, with a surgical approach, with complete removal as a goal.