Role of endoscopic ultrasound (EUS) and EUS-guided fine needle aspiration in the diagnosis and treatment of cystic lesions of the pancreas

Introduction and Aims: Cystic neoplasms of the pancreas may be inadvertently treated as benign pseudocysts in clinical practice, often without the use of cytology, cyst tumor markers, or histopathology. We assessed the utility of EUS-guided fine-needle aspiration (EUS-FNA) to assist in the diagnosis and management of pancreatic cysts. Methodology: All patients who had pancreatic cysts detected by EUS over a 24-month period were analyzed. Preoperative diagnosis was derived from an algorithm combining clinical history and endosonographic features. In selected cases, EUS-FNA was performed and cyst fluid aspirates Were analyzed. Surgical specimens served as diagnostic standard. Results: A total of 43 patients with pancreatic cysts underwent 45 EUS examinations. Surgical specimens were obtained from 9 patients (mucinous cystadenocarcinoma, 3; adenocarcinoma, 3; pancreatic endocrine tumor, 2; and benign cyst, 1); diagnostic EUS correctly predicted malignant cysts in 8/9 (88.9%). One case inaccurately interpreted by EUS as cystic neoplasm turned out to be a benign cyst on resection. Twenty-one patients underwent EUS-FNA. The cytologic interpretation was adenocarcinoma in 9.5% (2/21); suspicious for malignancy or atypical cells in 19.0% (4/21); benign in 66.6% (14/21); and insufficient cells in 4.8% (1/21). Conclusion: The information gathered from clinical history and EUS, complemented by fluid analysis after EUS-guided FNA, predicts neoplastic pancreatic cysts and assists in decision-making for medical or surgical approach.