The diagnostic performance of adrenal biopsy: a systematic review and meta-analysis

Objective: To perform a systematic review of published literature on adrenal biopsy and assess its performance in diagnosing adrenal malignancy. Methods: Medline In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trial were searched from inception to February 2016. Reviewersextracted data and assessed methodological quality in duplicate. Results: We included 32 observational studies reporting on 2174 patients (39.4% women, mean age 59.8 years) undergoing 2190 adrenal mass biopsy procedures. Pathology was described in 1621/2190 adrenal lesions (689 metastases, 68 adrenocortical carcinomas , 64 other malignant, 464 adenomas, 226 other benign, 36 pheochromocytomas, 74 other). The pooled non-diagnostic rate (30 studies, 2030 adrenal biopsies) was 8.6% (CI 6.1%-11%). The pooled complication rate (25 studies, 1356 biopsies) was 2.4% (CI 1.5%-3.3%). Studies were at a moderate risk for bias. Most limitations related to patient selection, assessment of outcome and adequacy of follow up. Only 8 studies (240 patients) could be included in the diagnostic performance analysis with sensitivity and specificity of 87% and 100% for malignancy; 70% and 98% for adrenocortical carcinoma ; and 87% and 96% for metastasis. Conclusions: Evidence based on small sample size and moderate risk of bias suggests that adrenal biopsy appears to be most useful in the diagnosis of adrenal metastasis in patients with a history of extra-adrenal malignancy. Adrenal biopsy should only be performed if the expected findings are likely to alter the management of the individual patient and after biochemical exclusion of catecholamine-producing tumors to help prevent potentially life-threatening complications.