In vivo detection of monosomy 3 in eyes with medium-sized uveal melanoma using transscleral fine needle aspiration biopsy

PURPOSE. Cytogenetic prognostication of choroidal melanoma, particularly monosomy 3 detections, is limited to enucleated eyes or resected tumors. The authors developed an in vivo technique to detect monosomy 3 using transscleral fine needle aspiration biopsy (FNAB). METHODS. Eight eyes with medium-sized choroidal melanoma were included in this prospective study. A 25-gauge transscleral FNAB was performed during surgical procedure for brachytherapy, just before applying the radioactive plaque over the tumor base. Sampled material underwent fluorescence in situ hybridization (FISH) with centromeric probes for chromosome 3. Follow-up was >12 months. RESULTS. Transscleral FNAB yielded sufficient material in 7 of 8 eyes (87.5%). Five of seven eyes had monosomy 3. No early or late complications were detected. CONCLUSIONS. This study demonstrates that medium choroidal melanomas may be safely sampled by intraoperative transscleral FNAB to detect monosomy 3 in vivo.