Endoscopic Diagnosis in Pancreatic Cancer

Seo, Dong Wan

Abstract

Pancreatic ductal adenocarcinoma is the most common malignancy occurring in the pancreas. This entity almost always shows fatal outcome and the complete cure is extremely difficult. The fatal outcome seems to be caused by the fact that this entity is usually diagnosed at its' advanced stage and the biological behavior is different from other curable types of malignancy. Endoscopic approach to the diagnosis of pancreas cancer comprises mainly of endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasonography (EUS). Upon ERCP, pancreatic cancer usually shows stricture or complete obstruction of main pancreatic duct and distal bile duct obstruction in case of pancreas head cancer. Endoscopic brush cytology, forcep biopsy or pancreatic juice analysis can offer histologic diagnosis but the sensitivity is very low. Upon EUS, pancreatic cancer is usually observed as a hypoechoic or mixed echogenic mass and outer margin of the mass becomes more indistinct as the size of the mass increases. EUS can offer more accurate local tumor staging than helical computed tomography, in terms of nodal involvement and vascular invasion. EUS-guided fine needle aspiration can give additional histological information of the mass and therapeutic strategy can be modified according to the histology and EUS staging. EUS has limitations in the diagnosis of distant nodal involvement and hepatic metastasis. Endoscopic approach can detect pancreatic mass with high sensitivity and especially EUS can give detailed information about local tumor extent. However, physician should also understand the benefits and limitations of other imaging modalities such as computed tomography or magnetic resonance cholangiopancreatography, and try to make more accurate diagnosis of the lesion and extent.