AUG 27, 2018
This study compared the cellular yield rate from transscleral and transvitreal fine-needle aspiration biopsies (FNAB) of small uveal melanoma.
Researchers retrospectively assessed 44 patients with small uveal melanoma (height range 2.3–2.9mm) who were treated at a single institution.
Transvitreal or transscleral biopsies were performed using 23- and 25-gauge needles. In transscleral biopsies, tumors were marked with a surgical marker to ensure adequate biopsy sites. Cryotherapy was applied as the needle was removed to destroy cells remaining on the needle tip. Transvitreal biopsy was done using a trocar in conjunction with chandelier lighting inserted at 180° opposite the tumor. For lesions smaller than 2.5 mm, clinicians used a thin needle to create a small hole in the retina over the tumor prior to harvesting cells with a 27-gauge cutter set with a low-cut rate. Intravitreal diathermy was applied if a second pass was necessary. Samples were aspirated with an aspiration gun. Cells were subsequently submitted for further genomic analysis.
All 11 samples obtained via the transscleral approach and 29 of 33 transvitreal samples had sufficient cells for genomic analysis. Gene expression profiling of 40 biopsies revealed 26 class 1A, 7 class 1B and 7 class 2 tumors. Four samples failed to amplify.
The most common transient complication was localized vitreous hemorrhage (24 cases), especially in transvitreal biopsies. However, only 3 lasted longer than 6 months. There were no retinal detachments or local recurrence of uveal melanoma. One patient developed metastatic disease and 1 patient underwent enucleation related to radiation retinopathy. Transvitreal biopsy correlated with localized hemorrhage at 1 day postop (phi value -0.526; P<0.001)
In addition to its retrospective nature, the study had a small sample size and short follow-up times. The authors did not discuss if infusion cannulas or BSS injections were used for IOP management during FNAB. It could have been beneficial to include the catalog information for the short bevel needles used for these procedures.
This article supports the safety and feasibility of using a transvitreal or transscleral approach for the biopsy of uveal melanoma tumors including in small uveal melanoma.