Clinical detection of melanoma-associated spongiform scleropathy by ultrasound biomicroscopy and its correlation with pathological diagnosis.

Comment. In our patient, the clinical suspicion of transretinal seeding by a uveal melanoma raised by SD-OCT could be confirmed histologically. Primary choroidal melanoma with retinal perforation and extension into the vitreous (Knapp-Rønne type) is a rare entity occurring in about 1 in 250 of uveal melanomas. Detection of retinal perforation is valuable owing to increased risk of recurrent vitreous hemorrhage after radiotherapy and increased likelihood of rhegmatogenous retinal detachment after transscleral local resection. However, early recognition of Knapp-Rønne melanoma can sometimes be a clinical challenge because ophthalmoscopic assessment, and even echography with a resolution of approximately 100 μm, might sometimes be too imprecise for imaging of focal retinal perforation. In contrast, conventional OCT produces cross-sectional images with approximately 10-μm resolution for visualization of microstructural alterations in retinal diseases as well as of the overlying retina in choroidal tumors. Recently, SD-OCT technology has improved resolution up to 3.5 μm per pixel. Using this technique, we could detect spheroidal bodies in the vitreous and, particularly, adjacent to the tumor apex where the overlying retina was completely obliterated. Although SD-OCT allows no exact differentiation between melanoma cells, melanomacrophages, or clusters of blood cells, our clinical findings presumed a KnappRønne melanoma that could be confirmed histologically. In the future, SD-OCT might become a helpful tool for clinical detection of vitreous seeding from uveal melanomas.