Yield, techniques, and complications of transvitreal and transscleral biopsies in small uveal melanoma

Importance: Intraoperative adequacy check of biopsy samples can lead to a higher biopsy yield rate, and subsequent genomic analysis can provide patients with valuable prognostic information.

Objectives: To examine the yield rates for transscleral and transvitreal fine-needle aspiration biopsies of small uveal melanoma less than 3.6 mm in apical height and to discuss techniques that would maximize yield rates and minimize complications.

Design, Setting, and Participants: A retrospective, consecutive observational case series was conducted from January 29, 2013, to May 23, 2017, at Retina Consultants of Houston and Houston Methodist Hospital among 44 patients with uveal melanoma of the ciliary body or choroid.

Interventions or Exposures: Fine-needle aspiration biopsy and intraoperative histopathologic analysis prior to iodine 125 brachytherapy.

Main Outcomes and Measures: Tumor locations and dimensions were identified by histopathologic analysis and B-scan ultrasonography. Either transscleral or transvitreal biopsy was performed for tumors anterior to the equator and posterior to the equator, respectively. Biopsy specimens were checked for adequacy intraoperatively. Specimens were examined using hematoxylin-eosin, double immunostain with human melanoma black 45 and Ki67, and gene expression profile.

Results: A total of 44 patients were included in the study, with a mean (SD) age of 63.3 (12.7) years (21 men [47.7%]; 23 women [52.3%]). Median tumor height was 2.7 mm (interquartile range, 2.3- 2.9 mm). Forty of 44 biopsy samples (90.9%; 95% CI, 82.4%-99.4%) yielded adequate cells for gene expression profile analysis. Transscleral and transvitreal yield rates were 11 of 11 (100%) and 29 of 33 (87.9%), respectively. Most localized vitreous hemorrhages were resolved by 3 months. There was a moderate association between localized vitreous hemorrhage and transvitreal biopsy method, for which the phi value was -0.526 (95% CI, -0.712 to -0.157; P < .001).

Conclusions and Relevance: These findings suggest intraoperative adequacy evaluation of fine-needle aspiration biopsy specimens leads to high yield and is more informative for patients.