Performance characteristics of EUS-FNA biopsy for adrenal lesions: A meta-analysis

Background and Objective: The role of EUS-FNA biopsy (EUS-FNAB) for detection of metastatic lesions (mets) to adrenals has not been evaluated systematically. Our aim is to systematically evaluate the performance characteristics of EUS-FNAB in detecting metastasis to the adrenal glands. Materials and Methods: We performed a systematic search on PubMed and OvidSP from January 1990 to July 2016 using various search terms for EUS and adrenal lesion. Only articles published in English literature were included in the study. Studies with fewer than 10 patients were excluded from the study. Publication bias was assessed using Begg-Mazumdar test and visual inspection of funnel plots. Results: Eight studies including 360 adrenal lesions that underwent EUS-FNAB were identified. Of these, 137 FNABs were conclusive for malignancy. Sensitivity of EUS-FNAB in detecting metastasis to the adrenals was 95% (95% confidence interval [CI]: 90%–98%) and specificity was 99% (95% CI: 96%–100%). Pooled positivity of EUS-FNAB in detecting lung cancer metastasis to the adrenals was 44% (95% CI: 31.5%–57.3%). No evidence of publication bias was noted. Conclusion: Our study demonstrates that EUS-FNAB is highly sensitive and specific in detecting metastasis to adrenals. It also shows that up to about half of the patients with lung cancer and adrenal lesions on imaging have metastasis, a finding with profound implications on lung cancer staging and treatment.