Abstract
Purpose::
To compare the cytologic and flow cytometry features of vitreous samples obtained using 20- or 25 gauge vitrectomy for intraocular lymphoma.
Methods::
Cells from a commercially available large B-cell line were suspended in rabbit vitreous that had been isolated from frozen enucleated globes (n=10). The biopsy of the suspension of cells in rabbit vitreous was performed using 20 gauge vitrectomy (Group 20G, n=5) or 25 gauge vitrectomy (Group 25G, n=5) at 1500cpm. Conventional flow cytometry using an ultrashort panel of markers and liquid based cytology were performed on the vitreous biopsy samples thus obtained and on controls (pure lymphoma B-cells and a vitreous sample without B-cells aspirated using 20G vitrectomy).
Results::
Flow cytometry demonstrated a similar mean cellular viability in the two groups (Group 20G: 48.5%, Group 25G: 58%, p=0.59) with 13.4% and 36.8% in Groups 20G and 25G respectively identified as large B-cells (p=0.11). Liquid-based cytology showed moderate cellularity of lymphoma cells in 5/5 samples in Group 20G and 2/5 in group 25G (p=0.03) with 3/5 samples in Group 25G having low cellularity of lymphoma cells. In all samples of each group, results of cytology or flow cytometry were adequate for identifying the presence of B-cell lymphoma.
Conclusions::
Samples obtained using 25-gauge vitrectomy have adequate cytologic and immunophenotypic features to allow the diagnosis of intraocular lymphoma, although cytology shows a statistically significant reduction in cellularity of lymphoma cells compared to 20-gauge vitrectomy.
Keywords: vitreoretinal surgery • pathology techniques • oncology