This image shows two color fundus photos taken approximately 1.5 years apart showing the progression of a subretinal pigmented lesion. While subretinal or choroidal hemorrhage is a reasonable guess, this case was selected to demonstrate the differences between choroidal nevus and melanoma. In this pair of images, one may observe the slight increase in size of the lesion (noted most clearly along the edge closest to the optic disc), increase in orange lipofuscin pigment and subretinal fluid. Another important risk factor for melanoma is whether the lesion is over 1mm in thickness.
An important distinguishing characteristic of choroidal nevus is the presence of drusen. This represents retina pigment epithelium (RPE) wear and tear that occurs due to the chronicity of these lesions in contrast to the faster growing melanomas.
For a quick overview:
http://www.aao.org/publications/eyenet/200610/oncology.cfm
Please feel free to post questions, comments, corrections!
Chordial nevus = "mole" of retina - usually benign and should be monitored. Should not grow.
ReplyDeleteMelanoma = most common malignancy to retina, will grow. How is thickness of the retina measured?
The gold standard for looking at melanoma is ultrasound with b-scan/a-scan. solid vs. hypo-echoic lesions are important to differentiate as well.
ReplyDeleteAnother important thing to remember is that not all melanomas are pigmented. amelanotic melanoma will be coming up in the near future!