There are several conditions that can clinically simulate iris melanoma (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34). Various tumors and cysts that can resemble iris melanoma are discussed in more detail elsewhere in this atlas and are only alluded to here because they relate to the differential diagnosis of iris melanoma. This section covers selected other nonneoplastic, noncystic conditions that can sometimes closely simulate iris melanoma, including iridocorneal endothelial (ICE) syndrome, foreign body, benign epithelioma (adenoma) of the iris pigment epithelium, and selected others.

The most common pseudomelanoma that we have seen is iris nevus (1,2). This tumor was discussed earlier. Another tumor that commonly simulates iris melanoma is epithelioma of the iris pigment epithelium. In contrast to melanoma, it is generally dark black and tends to push through the pigment epithelium from posteriorly. It does not appear to arise from the iris stroma as does a melanoma (11, 12, 13, 14). Lymphoid tumors can be confined to the iris and can be similar to melanoma (27, 28, 29, 30, 31).