Clinical and Pathologic Characteristics of Biopsy-Proven Iris Melanoma

Abstract

To collaborate with multiple centers to identify representative epidemiological, clinical, and pathologic characteristics of melanoma of the iris. This international, multicenter, Internet-assisted study in ophthalmic oncology demonstrates the collaboration among eye cancer specialists to stage and describe the clinical and pathologic characteristics of biopsy-proven melanoma of the iris. Methods: A computer program was created to allow for Internet-assisted multicenter, privacy-protected, online data entry. Eight eye cancer centers in 6 countries performed retrospective chart reviews. Statistical analysis included patient and tumor characteristics, ocular and angle abnormalities, management, histopathology, and outcomes. Results: A total of 131 patients with iris melanoma (mean age, 64 years [range, 20-100 years]) were found to have blue-gray (62.2%), green-hazel (29.1%), or brown (8.7%) irides. Iris melanoma color was brown (65.6%), amelanotic (9.9%), and multicolored (6.9%). A mean of 2.5 clock hours of iris was visibly involved with melanoma, typically centered at the 6-o'clock meridian. Presentations included iritis, glaucoma, hyphema, and sector cataract. High-frequency ultrasonography revealed a largest mean tumor diameter of 4.9 mm, a mean maximum tumor thickness of 1.9 mm, angle blunting (52%), iris root disinsertion (9%), and posterior iris pigment epithelium displacement (9%). Using the American Joint Commission on Cancer-International Union Against Cancer classification, we identified 56% of tumors as T1, 34% of tumors as T2, 2% of tumors as T3, and 1% of tumors as T4. Histopathologic grades were G1-spindle (54%), G2-mixed (28%), G3-epithelioid (5%), and undetermined (13%) cell types. Primary treatment involved radiation (26%) and surgery (64%). Kaplan-Meier analysis found a 10.7% risk of metastatic melanoma at 5 years. Conclusions: Iris melanomas were most likely to be brown and found in the inferior quadrants of patients with light irides. Typically small and unifocal, melanomas are commonly associated with angle blunting and spindle cell histopathology. This multicenter, Internet-based, international study successfully pooled data and extracted information on biopsy-proven melanoma of the iris.

Topography and clinical features of iris melanoma

“…It is generally believed that there is no gender predilection for the development of iris melanoma [ 7 ]. In the present study, there was a slight predominance of female patients (62%), and a similar female predominance has also been found by others [ 10 , 11 ]. The mean age at the time of diagnosis was 52 years, which is in accordance with many other studies showing that patients with iris melanoma are about a decade younger at presentation than those with posterior uveal melanoma [ 3 , 9 , 12 ].…”

Topography and clinical features of iris melanoma

“…It is generally believed that there is no gender predilection for the development of iris melanoma [ 7 ]. In the present study, there was a slight predominance of female patients (62%), and a similar female predominance has also been found by others [ 10 , 11 ]. The mean age at the time of diagnosis was 52 years, which is in accordance with many other studies showing that patients with iris melanoma are about a decade younger at presentation than those with posterior uveal melanoma [ 3 , 9 , 12 ].…”

Iris melanoma in an Australian cohort

“…We found that patients with iris melanoma in north‐eastern Australia tend to be middle‐aged Caucasians, with blue eyes, fair hair and light skin colour. This is in keeping with multiple previous reports from Europe and North America 17,18 . Tumours were typically brown, smaller than 5 mm and located in the inferior iris hemisphere.…”

“…Similarly, we demonstrated that close to half of our patients had greater than 3 iris freckles in their affected and non‐affected eyes. We also reported high numbers of tumours located inferiorly ( n = 74, 86%)—which has previously been linked to UVR exposure—as the superior orbital rim and upper eyelid shield the superior part of the iris from radiation 17,18,23 . Further to this, we found a 17% incidence of cutaneous melanoma in our study population, which is more than the expected rate in Queensland, Australia (estimated 64.3 per 100 000 persons new cases of melanoma per year)—highlighting a likely environmental association or genetic predisposition in our patients 24,25 …”

Cysts and tumours of the iris: Diagnostic tools and key management considerations—A review

“…These lesions were found to be partially or completely pigmented in 90%, with common additional features of correctopia (45%), glaucoma (35%), ectropion uveae (24%), angle seeding (28%, mean 2 clock hours), hyphaemia (3%) and extraocular extension (3%). These key features are also commonly reported by other authors 26,30,32,45,56,58,59 . With increasing age, there was also an increase in tumour basal diameter, IOP and seeding at the time of presentation 56 …”

Topography and clinical features of iris melanoma

“…It is generally believed that there is no gender predilection for the development of iris melanoma [ 7 ]. In the present study, there was a slight predominance of female patients (62%), and a similar female predominance has also been found by others [ 10 , 11 ]. The mean age at the time of diagnosis was 52 years, which is in accordance with many other studies showing that patients with iris melanoma are about a decade younger at presentation than those with posterior uveal melanoma [ 3 , 9 , 12 ].…”

Iris melanoma in an Australian cohort

“…We found that patients with iris melanoma in north‐eastern Australia tend to be middle‐aged Caucasians, with blue eyes, fair hair and light skin colour. This is in keeping with multiple previous reports from Europe and North America 17,18 . Tumours were typically brown, smaller than 5 mm and located in the inferior iris hemisphere.…”

“…Similarly, we demonstrated that close to half of our patients had greater than 3 iris freckles in their affected and non‐affected eyes. We also reported high numbers of tumours located inferiorly ( n = 74, 86%)—which has previously been linked to UVR exposure—as the superior orbital rim and upper eyelid shield the superior part of the iris from radiation 17,18,23 . Further to this, we found a 17% incidence of cutaneous melanoma in our study population, which is more than the expected rate in Queensland, Australia (estimated 64.3 per 100 000 persons new cases of melanoma per year)—highlighting a likely environmental association or genetic predisposition in our patients 24,25 …”

Cysts and tumours of the iris: Diagnostic tools and key management considerations—A review

“…These lesions were found to be partially or completely pigmented in 90%, with common additional features of correctopia (45%), glaucoma (35%), ectropion uveae (24%), angle seeding (28%, mean 2 clock hours), hyphaemia (3%) and extraocular extension (3%). These key features are also commonly reported by other authors 26,30,32,45,56,58,59 . With increasing age, there was also an increase in tumour basal diameter, IOP and seeding at the time of presentation 56 …”

Topography and clinical features of iris melanoma

“…It is generally believed that there is no gender predilection for the development of iris melanoma [ 7 ]. In the present study, there was a slight predominance of female patients (62%), and a similar female predominance has also been found by others [ 10 , 11 ]. The mean age at the time of diagnosis was 52 years, which is in accordance with many other studies showing that patients with iris melanoma are about a decade younger at presentation than those with posterior uveal melanoma [ 3 , 9 , 12 ].…”

Iris melanoma in an Australian cohort

“…We found that patients with iris melanoma in north‐eastern Australia tend to be middle‐aged Caucasians, with blue eyes, fair hair and light skin colour. This is in keeping with multiple previous reports from Europe and North America 17,18 . Tumours were typically brown, smaller than 5 mm and located in the inferior iris hemisphere.…”

“…Similarly, we demonstrated that close to half of our patients had greater than 3 iris freckles in their affected and non‐affected eyes. We also reported high numbers of tumours located inferiorly ( n = 74, 86%)—which has previously been linked to UVR exposure—as the superior orbital rim and upper eyelid shield the superior part of the iris from radiation 17,18,23 . Further to this, we found a 17% incidence of cutaneous melanoma in our study population, which is more than the expected rate in Queensland, Australia (estimated 64.3 per 100 000 persons new cases of melanoma per year)—highlighting a likely environmental association or genetic predisposition in our patients 24,25 …”

Cysts and tumours of the iris: Diagnostic tools and key management considerations—A review

“…These lesions were found to be partially or completely pigmented in 90%, with common additional features of correctopia (45%), glaucoma (35%), ectropion uveae (24%), angle seeding (28%, mean 2 clock hours), hyphaemia (3%) and extraocular extension (3%). These key features are also commonly reported by other authors 26,30,32,45,56,58,59 . With increasing age, there was also an increase in tumour basal diameter, IOP and seeding at the time of presentation 56 …”