gastrointestinal disorders
Pancreatic Cancer
Intraductal Papillary Mucinous Neoplasms
Intraductal papillary-mucinous neoplasms (IPMN) are cystic neoplasms that result in mucus hypersecretion and ductal obstruction. Histology may be benign, borderline, or malignant. Most (80%) tumors occur in women and in the tail of the pancreas (66%). IPMNs are broadly classified into three types: main duct, branch duct, and mixed type. Main duct IPMNis diagnosed when the tumor involves the main pancreatic duct. This usually results in main duct dilation (often to > 10 mm) as well as extrusion of mucin through the sphincter of Oddi. Main duct IPMN carries a high risk of underlying cancer, and people are routinely offered surgical resection when diagnosed. Branch duct IPMNis a result of neoplastic involvement of a side duct of the main pancreatic duct. These tumors do not lead to dilation of the main pancreatic duct. Unlike main duct IPMN, branch duct IPMN harbor a variable risk of cancer, and the decision to operate or survey the tumor is based on a series of imaging and endoscopic tests (often with biopsy and cyst fluid analysis). If surveillance is offered, it is usually a combination of imaging and endoscopic ultrasound. Mixed-type IPMNhas characteristics of both main duct and branch duct IPMN, namely resulting in dilation of both the main duct and its associated branch ducts. Mixed-type IPMN harbor the same malignancy risk profile as main duct IPMN and are treated similarly with surgical resection. Symptoms of IPMN consist of pain and recurrent bouts of Overview of Pancreatitis . Often, they are seen incidentally on cross-sectional imaging that is done for other reasons. Diagnosis of IPMN is made by cross-sectional imaging (CT or MRI). Often, endoscopic ultrasound with aspiration and cytology is used adjunctively to clarify the diagnosis. A classic finding on endoscopy that indicates main duct IPMN is a fish-mouth appearance caused by extrusion of mucin from the sphincter of Oddi. Surgical resection is the treatment of choice for patients with IPMN with high-grade dysplasia who have progressed to invasive carcinoma or who have features that suggest a high risk of developing cancer. For patients with underlying cancer, postoperative systemic therapy is similar to that for pancreatic adenocarcinoma. With surgery, 5-year survival is>95% for benign or borderline cases, but 50 to 75% for malignant tumors. 