Role of endoscopic ultrasound in the diagnosis of cystic lesions of the pancreas.

Endoscopic ultrasound (EUS) is an ideal imaging technique for pancreatic cystic lesions. Ultrasound is exquisitely sensitive for detecting and characterizing cysts arising in solid organs, and when the transducer is placed on an endoscope, high resolution imaging of the pancreas is achieved. Linear EUS can also guide needle aspiration of pancreatic cystic lesions and through the use of aspiration cytology, cystic tumors of the pancreas can be diagnosed. Since cytology is a relatively insensitive test, cyst fluid tumor markers such as CEA have been employed to improve the sensitivity for the detection of malignancy. Cyst fluid CEA values are uniformly low in serous cystadenomas, higher in mucinous lesions, and markedly elevated in mucinous cystadenocarcinomas. Through the use of these techniques, the ability to detect and diagnose early malignancies of the pancreas will be greatly enhanced.