Review of cystic and solid tumors of the iris

Abstract

Iris tumors are broadly classified into cystic or solid lesions. The cystic lesions arise from iris pigment epithelium (IPE) or iris stroma. IPE cysts classically remain stable without need for intervention. Iris stromal cyst, especially those in newborns, usually requires therapy of aspiration, possibly with alcohol-induced sclerosis, or surgical resection. The solid tumors included melanocytic and nonmelanocytic lesions. The melanocytic iris tumors include freckle, nevus (including melanocytoma), Lisch nodule, and melanoma. Information from a tertiary referral center revealed that transformation of suspicious iris nevus to melanoma occurred in 4% by 10 years and 11% by 20 years. Risk factors for transformation of iris nevus to melanoma can be remembered using the ABCDEF guide as follows: A=age young (<40 years), B=blood (hyphema) in anterior chamber, C=clock hour of mass inferiorly, D=diffuse configuration, E=ectropion, F=feathery margins. The most powerful factors are diffuse growth pattern and hyphema. Tumor seeding into the anterior chamber angle and onto the iris stroma are also important. The nonmelanocytic iris tumors are relatively uncommon and included categories of choristomatous, vascular, fibrous, neural, myogenic, epithelial, xanthomatous, metastatic, lymphoid, leukemic, secondary, and non-neoplastic simulators. Overall, the most common diagnoses in a clinical series include nevus, IPE cyst, and melanoma. In summary, iris tumors comprise a wide spectrum including mostly iris nevus, IPE cyst, and iris melanoma. Risk factors estimating transformation of iris nevus to melanoma can be remembered by the ABCDEF guide.

Keywords: Cyst; eye; iris; melanoma; metastasis; nevus; tumor.

Figure 1

Iris cysts (a,b) Iris pigment epithelial (IPE) cyst pupillary margin seen clinically (a) and by optical coherence tomography (b), (c) IPE cyst mid-zonal, (d) IPE cyst dislodged and in the anterior chamber angle, (e) Iris stromal cyst in an infant, (f) Iris stromal cyst with hemorrhage in an infant

Figure 2

Iris melanocytic tumors (a) Iris nevus (pigmented), (b) Iris nevus (nonpigmented) causing minor corectopia inferiorly, (c) Iris melanocytoma, (d) Iris Lisch nodules scattered on the entire iris surface, (e) Iris melanoma involving the anterior chamber angle, (f) Iris melanoma causing corectopia

Figure 3

Iris non-melanocytic tumors (a,b) Iris vascular tumor diagnosed as racemose hemangioma, barely seen clinically (a) as ectatic vessel, but more obvious on fluorescein angiography (b) as tortuous dilated vessel (c) Iris juvenile xanthogranuloma in a one-year-old child, (d) Iris lymphoid tumor, (e) Iris metastasis from breast cancer, (f) Iris metastasis from remote cancer

Figure 4

Non-neoplastic tumors simulating iris tumors (a) Iridocorneal endothelial syndrome with temporally directed ectropion, corectopia contracted iris and broad peripheral anterior synechiae, (b) Iridocorneal endothelial syndrome with broad peripheral anterior synechiae inferotemporally and iris adherence to endothelium with iris stromal tear, allowing visualization of the underlying iris pigment epithelium