Pancreatic Cysts & Tumors PDF

Pancreatic cysts & tumors Non-Neoplastic Cysts Congenital Cysts Congenital cysts are caused by anomalous development of the pancreatic ducts; in congenital polycystic disease, they frequently coexist with kidney and liver cysts. In von Hippel-Lindau disease pancreatic cysts and ang...

Pancreatic cysts & tumors Non-Neoplastic Cysts Congenital Cysts Congenital cysts are caused by anomalous development of the pancreatic ducts; in congenital polycystic disease, they frequently coexist with kidney and liver cysts. In von Hippel-Lindau disease pancreatic cysts and angiomas of the central nervous system (CNS) are seen. They are usually unilocular and thin-walled with a cuboidal epithelial lining. Pseudocysts Pseudocysts are collections of necrotic-hemorrhagic material rich in pancreatic enzymes; formed by walling off areas of fat necrosis, they account for 75% of pancreatic cysts. They are not lined by epithelium (thus, “pseudocysts”), rather they are encircled by fibrosed granulation tissue. They occur after bouts of acute pancreatitis or following trauma. While many spontaneously resolve, they can become secondarily infected or compress adjacent structures. Cystic Neoplasms Cystic tumors constitute less than 5% of pancreatic neoplasms; they typically occur as painless, slow-growing masses. Serous cystadenoma: Typically seen in women older than 60 years; these are usually solitary, well-circumscribed nodules with a central stellate scar. They are composed of numerous 1- to 3-mm cysts lined by a glycogen-rich cuboidal epithelium and containing serous, watery fluid. These are almost always benign and resection is curative.  Mucinous cystic neoplasm: These multiloculated cystic neoplasms are filled with thick mucinous material; the cysts are lined by mucin- producing columnar cells within a dense stroma. Almost 95% occur in women, and most arise as slow- growing painless masses in the body or tail of the gland. One third of these lesions harbor an invasive adenocarcinoma.  Intraductal papillary mucinous neoplasm (IPMN): These are intraductal mucin-producing neoplasms, more common in men than women. Most arise in the head of the gland, and 10% to 20% are multifocal. They differ from mucinous cystic neoplasms by lacking an associated dense stroma and by involving a larger pancreatic duct, but they have a similar malignant potential. Solid-pseudopapillary tumor: These round and well-circumscribed neoplasms have solid and cystic regions; they occur mainly in young women and cause abdominal discomfort due to their large size. These tumors are associated with activating mutations of b-catenin. Although some are locally aggressive, complete resection is usually curative.  Carcinoma of the pancreas is a common tumor. Incidence is increasing; the carcinoma is more common in smokers. The carcinoma is almost always adenocarcinoma. More often, the carcinoma arises in the head of the pancreas, causing obstructive jaundice (see Table 16-1); somewhat less often it originates in the pancreatic body or tail. Carcinoma involving the pancreatic tail can cause islet destruction and secondary diabetes mellitus.  Clinical manifestations may include abdominal pain radiating to the back, weight loss and anorexia, sometimes migratory thrombophlebitis (Trousseau sign), and frequently common bile duct obstruction resulting in obstructive jaundice (often accompanied by a distended, palpable gallbladder). Cancer is often silent before widespread dissemination occurs. Death usually results within 1 year.