Transformation of nevus to melanoma, or not?

A 51-year-old Caucasian woman with history of stable submacular choroidal nevus in the right eye (OD) noted blurred vision for 3 weeks. Visual acuity was 20/200 OD and 20/50 in the left eye. Both eyes showed mild cataract. Funduscopy revealed a stable pigmented choroidal nevus OD, but with new development of subretinal hemorrhage and shallow overlying fluid, extending into the foveola. The mass appeared hypoautofluorescent centrally, with hyperautofluorescence in the subretinal fluid (SRF). Fluorescein angiography (FA) showed pinpoint leakage most intense along the inferonasal margin, suggestive of choroidal neovascularization membrane (CNVM).

What Is Your Next Step?

Initiate plaque radiotherapy

Perform photodynamic therapy (PDT) with verteporfin

Perform intravitreal antivascular endothelial growth factor (VEGF) injection

Observe the lesion for 3 months [Fig. 1].

Findings

Fundus photography (A) documented the elevated choroidal lesion along the inferotemporal parafoveal region. The lesion was echodense and measured 1.5 mm in thickness by B-scan ultrasonography. On late-phase FA (B), diffuse hyperfluorescence was seen overlying the mass, representing SRF and most intense near the foveola, suggestive of CNVM. Optical coherence tomography (OCT) (C) confirmed shallow SRF with debris (blood) and retinal pigment epithelial detachment (not shown). OCT angiography (OCTA) (D) depicted a prominent CNVM with a “sea-fan”appearance.

Diagnosis: Choroidal nevus with CNVM and subretinal hemorrhage.

Correct Answer: C.

Discussion

The development of CNVM secondary to choroidal nevus is rare, occurring in <1% of cases.[1] Most choroidal nevi with CNVM are chronic, stable tumors with minimal potential for malignant transformation. However, SRF, orange lipofuscin pigment, and hemorrhage can occasionally represent ominous signs heralding growth into melanoma.[1] The presence of visible CNVM on OCTA and leakage on FA are features supportive of a neovascular, rather than malignant process.[2] The treatment of submacular CNVM overlying choroidal nevus is important for preservation of vision. Chiang et al. demonstrated CNVM response using intravitreal anti-VEGF (bevacizumab), with occasional need for PDT or laser photocoagulation consolidation.[3]

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Conflicts of interest

There are no conflicts of interest.