Ductal Adenocarcinoma

Abstract

PathologyDuctal adenocarcinoma is a malignant epithelial neoplasm with glandular (ductal) differentiation, without a predominant component of any other types of carcinoma [ 7 ].Sixty to seventy percent of ductal adenocarcinomas is located in the pancreatic head, 30 % in the body and tail, and 5 % involve the whole organ. Multifocal disease has been reported as well as synchronous or metachronous carcinomas.Carcinomas of the pancreatic head tend to cause symptoms such as painless jaundice, acute pancreatitis, and epigastric pain that radiates to the back.Carcinomas of the body-tail of the pancreas often present with unexplained weight loss, back pain, or distant metastases.Sudden onset of diabetes mellitus may be the fi rst sign of pancreatic cancer. 2Carcinomas of the pancreatic head are usually diagnosed earlier and are more often resectable than carcinomas that involve the body-tail.Surgically resected carcinomas of the pancreatic head are generally signifi cantly smaller than the tumors of the body and tail (2-3 cm versus 5-7 cm, respectively). MacroscopyOn the cut surface, the tumor usually appears as a solid fi rm mass with infi ltrative, indefi nable margins, whitish color, and hard consistency.The tumor is often surrounded by a phlogistic fi brous "cuff," derived from a focal peritumoral pancreatitis, making it sometimes hard to identify the actual dimensions of the tumor, both at imaging and macroscopically.Extensive areas of hemorrhage and necrosis with cystic cavitation are uncommon, but microscopic foci are not so uncommon.Carcinomas of the pancreatic head, with the exception of those arising in the uncinate process, almost always infi ltrate both the common bile duct and Wirsung's duct, leading to a variable degree of stenosis and upstream dilation (radiological "double-duct sign"). This causes jaundice and upstream obstructive pancreatitis, which could lead to chronic pancreatitis, characterized by the presence of fi brotic or fi bro-adipous components, associated with a variable degree of acinar cells atrophy, with duct dilatation and retention cysts formation.The involvement of duodenum and/or Vater's ampulla, frequently found in the carcinomas of the pancreatic head, causes retraction of the intestinal wall, and eventually mucosal ulceration.Invasion and thrombosis of large peripancreatic vessels, such as the splenic vein, are frequently observed in bodytail carcinomas.The pathological evaluation of the retroperitoneal resection margin provides the most important information about local recurrence and patient survival. This margin is defi ned as the peripancreatic adipose tissue behind the head of the pancreas, which is located ventral and lateral, in respect to the superior mesenteric artery [ 8 -11 ].When the tumor involves the celiac trunk or the superior mesenteric artery, it is considered unresectable; so, this involvement is rarely present in surgical pathology specimens. A focal and partial, noncircumferential, adhesion of the posterior pancreatic surface to the mesenteric vein may justify ...