Fine-Needle Aspiration Biopsy for Molecular Genomic Classification: Evaluation of Transscleral vs Transvitreal Biopsy

Purpose: To evaluate the transvitreal and transscleral fine-needle aspiration biopsy (FNAB) approach for molecular classification with gene-expression profiling (GEP) of uveal melanoma. Methods: Institutional review board–approved single-surgeon retrospective analysis of a consecutive case series of all patients undergoing FNAB using a 25-gauge-needle multipass approach for GEP analysis of uveal melanoma between 2012 and 2016. All FNAB specimens were processed for uveal melanoma diagnostic testing using a standard processing approach, and all testing was completed at a single laboratory (Castle Biosciences, Inc.). Results: Three hundred fifty-three eyes (353 patients) were included. Transvitreal biopsies were performed in 216 eyes (216/353, 61.2%), whereas transscleral biopsies were performed in 137 eyes (137/353, 38.8%). Twenty biopsies exhibited multiple gene failure (20/353, 5.6%). Excessive fluid biopsy volume was the primary association with reported multiple gene failure, occurring in 10 of 20 eyes (50%). FNAB performed via the transvitreal approach was significantly more likely to have an excessive volume report compared with transscleral biopsy (18/216, 8.3% vs 1/137, 0.7%; P < .001). Conclusions: FNAB performed via a transscleral or transvitreal multipass approach utilizing a 25-gauge needle achieves molecular classification in 95% of all patients undergoing treatment for presumed uveal melanoma independent of tumor size. Complications related to FNAB using these techniques are rare and may be associated with the presentation of the uveal melanoma.