Fine-needle aspiration cytology of adrenal masses: a re-assessment with histological confirmation

Background: Fine-needle aspiration (FNA) of adrenal masses is a method currently indicated in lesions suspected of being extra-adrenal in origin; even though its diagnostic reliability has already been determined in many studies, few have used histological examination obtained after adrenalectomy for diagnostic confirmation. Aim: to analyze the diagnostic performance of adrenal FNA in subjects with an available histological confirmation. Subjects and Methods: 50 subjects (26 benign adrenal lesions, 9 primary malignant lesions and 15 metastatic lesions) who had undergone ultrasound-guided adrenal FNA and then adrenalectomy were re-analyzed retrospectively. Results: FNA guaranteed a sensitivity of 85.7% and a specificity of 100% in all subjects; after having divided the subjects into oncologic and non-oncologic groups, the sensitivity of the test in oncologic patients (100%) increased significantly compared to non-oncologic (57.1%) with no difference in specificity (100% in both groups). Considering also non-diagnostic samples in our analysis (n=11; 22% of all samples studied), FNA correctly diagnosed malignancy only in 75% of the cases and benignancy only in 66.6%; however, even after including non-diagnostic samples, the percentage of correct malignancy diagnosis remained significantly higher in oncologic (93.3%) than in non-oncologic patients (44.4%) without significant statistical difference between the two groups regarding the percentage of correct benignancy diagnosis (respectively 100% and 63.6%). Conclusions: Our study, based on histological confirmation, underlines the low discriminant value of US-guided adrenal FNA though the method may have value in oncologic patients.