Management of cystic lesions of the pancreas

Pancreatic cystic lesions are being increasingly identified. Clinical decision making is driven by the differential diagnosis of the cyst and, for the asymptomatic patient, its likelihood of causing harm. The fundamental issue is whether the cyst is neoplastic, and, if so, what is its risk for malignant degeneration. High-resolution computed tomography provides detailed information about cyst structure and may facilitate differentiation from mucin-secreting tumors of the pancreas. Magnetic resonance imaging has the potential added advantage of determining communication between the cyst and pancreatic duct. Endoscopic ultrasound (EUS) imaging provides additional characterization of the lesion. While EUS morphology alone has limitations regarding definitive diagnosis, aspiration, and characterization of cyst, fluid contents may provide incremental information. Aspiration is well tolerated and safe, with a complication rate of less than 1%. In the absence of a history of pancreatitis, pseudocyst is quite unlikely, and the concern of a cystic neoplasm is paramount. In general, all symptomatic lesions should proceed to appropriate surgical resection. If preoperative characterization of the lesion will change management, EUS + FNA for cytology and fluid analysis (CEA) may characterize the lesion as mucinous, although cytology alone is rarely definitive. For those patients with benign-appearing lesions, such as classic appearance of a serous cystadenoma, observation alone seems appropriate. In some circumstances, EUS + FNA confirmation of a negative cytology and low fluid CEA can further provide evidence to support a monitoring approach and deferral of surgical intervention.