To determine the incidence of Chromosome 3 monosomy in iris melanoma using fine needle aspiration biopsy.
Noncomparative case series of 17 patients. Fine needle aspiration biopsy was performed intraoperatively immediately before treatment of iris melanoma. Genetic analysis using DNA amplification and microsatellite assay was performed in the specimen.
Clinical features and outcomes related to Chromosome 3 monosomy were reviewed. Disomy 3 was found in 5 melanomas (29%), partial Monosomy 3 in 7 melanomas (41%), and complete Monosomy 3 in 5 melanomas (29%). The only feature statistically associated with partial/complete Monosomy 3 (vs. Disomy 3) was older patients' age (median, 60 vs. 46 years, P = 0.03). A comparison of clinical features showed Monosomy 3 (vs. Disomy 3) tumors to be thinner (median, 2.8 vs. 4.2 mm) and with smaller base (median, 5.1 vs. 10 mm) but with greater iris seeding (mean, 5.7 vs. 2.4 clock hours) and greater angle seeding (mean, 3.2 vs. 0 clock hours), producing elevated intraocular pressure <22 mmHg (17 vs. 0%). Monosomy 3 tumors showed mixed/epithelioid cell type in 80% versus 0% in Disomy 3 (P = 0.14). No patients developed local melanoma recurrence or melanoma-related metastasis or death in the short 16-month mean follow-up.
Using fine needle aspiration biopsy, cytogenetic analysis can be achieved in iris melanoma. Iris melanoma demonstrated partial or complete Monosomy 3 in 71%, and this statistically correlated with increasing patients' age. Mixed/epithelioid cell type was far more commonly seen in patients with Monosomy 3, although this did not reach statistical significance.
Cytogenetic analysis of iris melanoma in 17 eyes revealed Monosomy 3 in 12 patients. Melanomas with Monosomy 3 displayed greater tumor seeding, elevated intraocular pressure, and mixed/epithelioid cell type. The only feature statistically correlated with Monosomy 3 was older patients' age (P = 0.03).
From the *Ocular Oncology Service, Wills Eye Institute, Thomas Jefferson University, Philadelphia, Pennsylvania; †Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, and ‡Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
Support provided by the Retina Research Foundation of the Retina Society in Cape Town, South Africa (C.L.S.), the Paul Kayser International Award of Merit in Retina Research, Houston, TX (J.A.S.), a donation from Michael, Bruce, and Ellen Ratner, New York, NY (J.A.S. and C.L.S.), the Mellon Charitable Giving from the Martha W. Rogers Charitable Trust, Philadelphia, PA (C.L.S.), the LuEsther Mertz Retina Research Foundation, New York, NY (C.L.S.), and the Eye Tumor Research Foundation, Philadelphia, PA (C.L.S.). Statistical analysis provided by D. Mohan. The funders had no role in the design and conduct of the study, in the collection, analysis, and interpretation of the data, and in the preparation, review, or approval of the article. C. L. Shields has had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Reprint requests: Carol L. Shields, MD, Ocular Oncology Service, Suite 1440, Wills Eye Institute, 840 Walnut Street, Philadelphia, PA 19107; e-mail: firstname.lastname@example.org