To evaluate the feasibility of genetic testing of uveal melanoma using fine-needle aspiration biopsy (FNAB).

Noncomparative case series of 140 patients in which FNAB was performed immediately prior to plaque radiotherapy. The specimen was sent for genetic analysis using DNA amplification and microsatellite assay for evaluation for monosomy 3.

Monosomy 3 was found in 44 cases (32%) and disomy 3 in 76 cases (54%); genomic DNA yield was insufficient for genetic analysis in 20 cases (14%). Monosomy 3 was found in 26% of small melanomas (16/61), 36% of medium melanomas (24/67), and 33% of large melanomas (4/12). Adequate DNA was achieved in 97% of cases using a 27-gauge needle via transvitreal tumor apex approach and in 75% of cases using a 30-gauge needle via transscleral tumor base approach. Factors predictive of monosomy 3 included greater tumor basal dimension (P = .016) and greater distance from the optic disc (P = .019). Transient localized vitreous hemorrhage was found in 46% of eyes. There was no case of diffuse vitreous hemorrhage, retinal detachment, or tumor recurrence along the biopsy tract.

FNAB provides adequate DNA in most cases for genetic analysis of uveal melanoma using microsatellite assay.