Groove pancreatitis.

Groove pancreatitis is a segmental chronic pancreatitis that affects the anatomical area between the pancreatic head, the duodenum, and the common bile duct, referred to as the groove area. Most patients with groove pancreatitis are males aged 40-50 years with a history of alcohol abuse. In about 20% of patients undergoing pancreaticoduodenectomy to treat chronic pancreatitis, groove pancreatitis is detected. The clinical symptoms are weight loss, upper abdominal pain, postprandial vomiting, and nausea due to duodenal stenosis. The pathogenesis of groove pancreatitis is thought to be anatomical or functional obstruction of the minor papilla. The viscosity of pancreatic juice increases due to excessive alcohol consumption and/or smoking, leading to calcification of the pancreatic duct. According to these conditions, pancreatitis in the groove area might arise due to impaired pancreatic juice outflow. The descending part of the duodenum is usually stenotic. Severe fibrosis and scarring are evident in the groove area. Characteristic pathological findings are cystic lesions in the duodenal wall, Brunner gland hyperplasia, dilation of Santorini's duct and protein plaques in the pancreatic duct. A differential diagnosis of groove pancreatitis from peripancreatic cancer is clinically important. Cystic lesions in the duodenal wall and smooth stenosis of the bile duct are important findings of groove pancreatitis revealed by endoscopic ultrasonography, computed tomography and magnetic resonance imaging. Biopsy through the duodenum is also useful for diagnosis. Conservative treatment options include endoscopic stenting of the minor papilla, but long-term outcomes remain unclear. Pancreatoduodenectomy is a rational treatment for symptomatic groove pancreatitis.