Is Endoscopic Ultrasonography-Guided Fine Needle Aspiration Trailblazing in Tissue Sampling of Adrenal Masses?

developments in imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) have led to increased detection of adrenal tumors. 1 Most incidentally discovered adrenal masses are biochemically non-functioning, and only 2% are metastases from various cancers. Approximately 75% of adrenal masses that are found during the staging of patients with cancer are metastases from melanomas, carcinomas of the lung and breast, renal cell carci-nomas, or lymphomas. 2 Current imaging methods cannot sufficiently differentiate benign from malignant masses. Therefore , ultrasonography-or CT-guided fine needle aspiration (FNA) have traditionally been used for tissue sampling of the adrenal glands. 3 Recently, with the emergence of endoscopic ultrasonography (EUS) and accessories, EUS-guided FNA has been used for adrenal gland biopsy. Eloubeidi et al. 4 reported that the false-positive rates of diagnosis of CT and MRI were 21% and 50%, respectively, meaning that a benign lesion was classified as a metastasis. Recently, positron emission tomography (PET) has been used to predict adrenal gland metastasis in patients with lung cancer. A systematic analysis by Stone et al. 5 showed that although PET had high sensitivity and specificity for malignant adrenal masses in patients with lung cancer, adrenal biopsy was recommended for confirming the imaging findings. However, adverse events related to percutaneous adrenal biopsies included hemorrhage, tract seeding. 6 We need to establish a new methodology for tissue sampling of adrenal masses in patients with lung cancer. EUS-guided FNA, which has few adverse events, may be better than percutaneous biopsies. On EUS imaging, a normal adrenal gland hasa seagull shape. Complete evaluation of the right adrenal gland is more technically challenging than the left adrenal gland. For example, one study reported that the right adrenal gland could be visualized by EUS in 87.3% of patients, whereas the left was visualized in all of the patients. 7 In this particular report, tuberculosis of the adrenal gland showed low echoic features with or without ne-crotic foci compared with other causes, and metastatic lesions displayed variable shapes such as enlargement of one limb or focal nodules. 8 Interestingly, no radiological evidence of tuberculosis was found in other sites among the patients. However, alterations in the shape of the adrenal gland with focal lesions and enlargement of only one limb were observed. Eloubeidi et al. 4 reported that EUS had an accuracy of 68% when used to distinguish benign from malignant masses based on size (≥30 mm). Therefore, …