Cutaneous melanoma metastatic to the vitreous cavity and deposition of melanoma cells over the epiretinal membrane
C. Perform pars plana vitrectomy and excisional biopsy of the membrane
The patient underwent diagnostic and therapeutic pars plana vitrectomy (Figure 2) during which vitreous biopsy and epiretinal membrane peeling were performed. Pathology and immunohistochemistry of the membrane and cytology of the vitreous confirmed the diagnosis of metastatic cutaneous melanoma (CM) (Figure 2).
Metastasis is the most common intraocular neoplasia and is most commonly associated with primary breast and lung tumors; however, the eye is an unusual site for CM metastasis, and when it occurs, the most common site of involvement is the choroid.1,2 In contrast, the vitreous is an exceptionally rare site of metastasis for any cancer, including CM. A large recent multicenter case series revealed that the median age at presentation for vitreous CM metastasis was 66 years, the median time from starting immunotherapy to ocular symptoms was 17 months, and 10 of 11 patients were treated with ICIs at some point in the treatment course.2 This is consistent with our case findings.