The Diagnostic Utility of Fine Needle Aspiration Biopsy for Evaluating Ocular Lesions

Summary: Introduction: Fine needle aspiration biopsy (FNAB) has been used to diagnose ocular lesions including Uveal Melanoma (UM), Ocular Lymphomas (OL), and Metastatic Ocular Disease (MOD). However, utilizing limited FNAB material to perform ancillary studies is challenging. This study assesses FNAB's efficacy in obtaining material for ancillary testing. Materials and Methods: We analyzed demographic data, cytologic diagnoses, and ancillary testing outcomes from ocular FNABs conducted between January 2018 and December 2022. Ancillary studies were defined as molecular testing (RT-PCR at Castle Biosciences) for suspected UM, flow cytometry for suspected lymphoma, and immunohistochemistry for suspected metastases. Results: FNABs were performed for suspected UM (Figure 1a) in 59 patients. The mean age was 61.3 years; male to female ratio was 0.6. Diagnostic categories included malignant, suspicious for malignancy, atypical, and negative for malignancy. Table 1 shows the distribution of these diagnoses. The collected material was sufficient for molecular testing in all patients. FNABs were performed for suspected OL (Figure 1b) in 24 patients. The mean age was 64.1 years; male to female ratio was 1.2. See Table 1. The collected material was sufficient for flow cytometry in all malignant and suspicious for malignancy cases, 33% of atypical cases, 64% of negative cases, and 50% of nondiagnostic cases. FNABs were performed for suspected MOD (Figure 1c-d) from an extraocular primary mass in 9 patients. The mean age was 54.9 years; male to female ratio was 2.0. All cases had an extraocular primary diagnosis. See Table 1. Sufficient material was collected for immunohistochemistry in all cases but one. Conclusions: FNABs provided sufficient material for molecular testing in UMs, even with nondiagnostic results. However, adequacy for ancillary studies in OL and MOD varied, emphasizing the importance of awareness of the clinical suspicion and subsequent sample adequacy.