British Journal of Ophthalmology
With multimodal imaging, subtle details of choroidal nevi can be observed, potentially leading to earlier detection of incipient melanoma and better prognosis. Dalvin et al. used high-resolution ultrasonography, fundus autofluorescence (AF), and spectral-domain optical coherence tomography (OCT) to examine choroidal nevi. They found that certain combinations of previously identified risk factors signal a high risk of progression to melanoma.
This retrospective study included 3,806 choroidal nevi (in 3,584 eyes of 3,334 patients), diagnosed consecutively during a 10-year period. In a prior study, these cases were evaluated by clinical examination and multimodal imaging, and six risk factors for transformation to melanoma were identified:
- tumor thickness >2 mm on ultrasonography
- presence of subretinal fluid on OCT
- visual acuity loss to 20/50 or worse
- orange pigment by AF
- hollow acoustic density on ultrasonography
- largest basal tumor diameter >5 mm by photography
In this study, a total of 2,355 nevi (2,211 eyes; 2,075 patients) were monitored for an average of three years (range, <1-11 years). No nevus had all six risk factors. The five-year Kaplan-Meier estimated risk of a choroidal nevus transforming to melanoma was 1% with no risk factor (hazard ratio [HR], 0.1), 11% with one factor (range, 9-37%; HR, 2.1-7.8), 22% with two factors (range, 12%-68%; HR, 1.8-12.1), 34% with three factors (range, 21%-100%; HR, 4.0-24.4), and 55% with four or five factors (range, 0%-100%; HR, 4.6-170.0 and 12.0-595.0, respectively). The highest-risk combination of three factors included decreased visual acuity, orange pigment, and hollow acoustic density (HR, 29.0). Among nevi with four risk factors, the most concerning combination was tumor thickness >2 mm, subretinal fluid, visual acuity loss, and orange pigment (HR, 170). Risk factors responsible for the highest HR, in any set of two to five factors, were visual acuity loss and orange pigment.
The authors recommend multimodal imaging to guide choroidal nevi management. Detecting high-risk features may prompt referral to an ocular oncologist, whereas observation may be adequate for lower-risk nevi.
The original article can be found here.