Objective: To evaluate the feasibility of genetic testing of uveal melanoma using fine-needle aspiration biopsy (FNAB).
Methods: We reviewed the clinical records of all patients of the Ocular Oncology Service at Wills Eye Hospital with the diagnosis of uveal melanoma who underwent FNAB for genetic testing for chromosome 3 status between November 1, 2005, and March 1, 2006. The FNAB was performed immediately before plaque radiotherapy. The specimens underwent genetic analysis using DNA amplification and microsatellite assay to determine the presence of monosomy 3.
Results: A total of 140 eyes of 140 patients with uveal melanoma were sampled for chromosome 3 abnormalities using FNAB. Monosomy 3 was found in 44 cases (31%), disomy 3 was found in 76 cases (54%), and the genomic DNA yield was insufficient for genetic analysis in 20 cases (14%). Monosomy 3 was found in 16 of 61 small melanomas (26%), 24 of 67 medium melanomas (36%), and 4 of 12 large melanomas (33%). Adequate DNA was achieved in 97% of cases using a 27-gauge needle via the transvitreal tumor apex approach and in 75% of cases using a 30-gauge needle via the transscleral tumor base approach. Factors predictive of monosomy 3 included greater tumor basal dimension (P=.02) and greater distance from the optic disc (P=.02). Transient localized vitreous hemorrhage was found in 46% of eyes. No cases of diffuse vitreous hemorrhage, retinal detachment, or tumor recurrence along the biopsy tract were found.
Conclusion: We found that in most cases, FNAB provides adequate DNA for genetic analysis of uveal melanoma using microsatellite assay.