Variable Results for Uveal Melanoma-Specific Gene Expression Profile Prognostic Test in Choroidal Metastasis.

Abstract

We report our experience with uveal melanoma-specific gene expression profile (GEP) testing on a series of choroidal metastatic tumors confirmed by cytopathology so that clinicians may be aware that receiving a class 1 or class 2 test result in nonmelanoma is possible. Retrospective review of all cytopathology and DecisionDx-UM GEP reports between January 2012 to December 2014 from intraoperative fine-needle aspiration biopsy of choroidal tumors undergoing brachytherapy. Four patients were identified to have cytopathology consistent with a nonmelanoma primary. All 4 patients presented with a unilateral, single choroidal tumor, which was treated with iodine-125 brachytherapy and underwent intraoperative fine-needle aspiration biopsy for cytopathology and uveal melanoma-specific GEP testing for molecular prognostication. Gene expression profile testing of the choroidal tumor in each patient revealed class 1A in 3 patients and class 2 in 1 patient. DecisionDx-UM GEP may be a helpful test for molecular prognostication in patients with uveal melanoma; however, class 1 and class 2 test results are indeed possible in the setting of a nonmelanoma malignancy. We recommend that cytopathology and/or other melanoma-specific testing be performed in all cases of suspected choroidal melanoma because GEP with this assay is unable to rule out the diagnosis of a choroidal melanoma.