Endoscopic diagnosis and staging of mucinous cystic neoplasms and intraductal papillary-mucinous tumors

Background/Purpose. The number of patients with cystic neoplasms of the pancreas as detected using various types of imaging techniques has been steadily increasing. Among the cystic neoplasms, mucinous cystic neoplasms (MCNs) and intraductal papillary-mucinous tumors (IPMTs) were comparatively more frequently encountered. We used imaging techniques to focus on the differential diagnosis of MCNs and IPMTs, and tumor staging. Methods. Fifteen patients with MCNs with ovarian-like stroma and 109 patients with IPMTs were experienced. We examined the image findings for the differential diagnosis and stage diagnosis of these two types of cystic neoplasms. Results. Endoscopic ultrasonography could reveal detailed images of internal structure and was effective for the diagnosis of MCNs. Other endoscopic imaging modalities could not give specific findings for MCNs. Endoscopic retrograde cholangiopancreatography (ERCP; including duodenoscopic findings and pancreatogram) and pancreatoscopy showed the characteristic and specific findings of IPMTs. Also, endoscopic ultrasonography and intraductal ultrasonography were found to have high sensitivity and diagnostic accuracy for their differential diagnosis of neoplastic/nonneoplastic and invasive/noninvasive lesions in IPMTs. Conclusions. Endoscopic imaging techniques are capable of revealing the detailed structure of pancreatic cystic lesions. They are effective for differential diagnosis, for assessing the degree of malignancy, and for deciding upon an appropriate treatment in patients with IPMTs.