Differential diagnosis of iris melanoma. A, Iris freckles are small and overlie the stroma. Multiple Lisch nodules in neurofibromatosis on a brown iris (B) and a blue iris (C). D, Congenital ocular melanocytosis is equivalent to a diffuse nevus, but is associated with pigmented patches in the episclera and sclera. Note the color variation and velvety stromal thickening in the iris. E, A pigment epithelial cyst (asterisk) can bow the iris forward in the area of the cyst, which is visible after dilation. F, Metastasis from pulmonary carcinoma (arrow).