Distinguishing Choroidal Nevi from Melanomas Using the MOLES Algorithm: Evaluation in an Ocular Nevus Clinic

Objective The aim of this study was to determine the sensitivity and specificity of the MOLES scoring system in differentiating choroidal melanomas from nevi according to Mushroom shape, Orange pigment, Large tumor size, Enlarging tumor, and Subretinal fluid (SRF). Methods Color photographs, fundus-autofluorescence images, and optical coherence tomography of 222 melanocytic choroidal tumors were reviewed. Each MOLES feature was retrospectively scored between 0 and 2 and tumors categorized as "common nevus," "low-risk nevus," "high-risk nevus," and "probable melanoma" according to the total score. MOLES scores were compared with the experts' diagnosis of melanoma. Results The MOLES scoring system indicated melanoma in all 81 tumors diagnosed as such by ocular oncologists (100% sensitivity) and nevus in 135 of 141 tumors given this diagnosis by these experts (95.7% specificity). Of the 6 tumors with discordant diagnoses, 4 had basal diameters exceeding 6 mm, all with SRF and/or orange pigment, and 2 small tumors showed either significant SRF with traces of orange pigment, or vice versa. Conclusions The MOLES system for diagnosing melanocytic choroidal tumors compares well with expert diagnosis but needs to be evaluated when deployed by ophthalmologists and community optometrists in a wide variety of working environments.