559 Int. J. Morphol., 29(2):559-561, 2011. A Classic Case of Annular Pancreas and its Clinical Implications Un Caso Clásico de Páncreas Anular y sus Implicaciones Clínicas ** Satheesha Nayak B. & ** Ooi Mun Yooi NAYAK, B. S. & MUN YOOI, O. A classic case of annular pancreas and its clinical implications. Int. J. Morphol., 29(2):559-561, 2011. SUMMARY: Annular pancreas is a rare developmental anomaly where the head of the pancreas surrounds the second part of the duodenum like a ring. This may cause the duodenal constriction, obstruction, peptic ulcers and other complications. We saw a classic case of annular pancreas. The head of pancreas surrounded the second part of duodenum completely. However there was no narrowing of the duodenum. The case may be of importance for gastroenterologists, surgeons and radiologists. KEY WORDS: Pancreas; Annular pancreas; Duodenum; Anomaly. INTRODUCTION The pancreas is a soft lobulated gland that is situated close to the posterior abdominal wall. It is about 15-20 cm long and weighs about 90 gm in weight. It is a mixed gland; partly exocrine and partly endocrine. The exocrine part is represented by the serous pancreatic acini and drained by a major and an accessory pancreatic duct. The major pancreatic duct joins with the common bile duct to form the hepatopancreatic ampulla which opens into the second part of the duodenum on the summit of the major duodenal papi- lla. The accessory pancreatic duct opens into the second part of the duodenum on the summit of the minor duodenal pa- pilla. The endocrine part is represented by islets of Langerhans which secrete insulin and glucagon. The pancreas has a head, a neck, a body, a tail and an uncinate process. The head fits into the curve of the duodenum, the body crosses in front of the vertebral column and the tail touches the hilum of pancreas. All the parts except the tail are retroperitoneal. We observed only one case of annular pancreas among more than 100 cadavers dissected in the last fifteen years. CASE REPORT During routine dissection for the undergraduate medical students, we observed the classic annular pancreas. This anomaly was noted in cadaver age 50 years approximately. The head of the pancreas made a circle around the second part of the duodenum (Fig 1). The annulus was also closely related to the inferior surface of the right lobe of the liver and the anterior surface of the right kidney and the right renal vessels. The neck, body and tail of the pancreas were normal and had the normal relations. There were no other notable variations in the cadaver. DISCUSSION One of the most interesting but rare variations of the pancreas is the condition known as the ‘annular pancreas’. In this condition the descending part (2nd part) of the duodenum is surrounded by a ring of pancreatic tissue that is continuous with the head of the pancreas. It may be associated with a constriction of the duodenum at the location of the ring, with dilations above and below. The pancreas develops from the endoderm of the caudal end of the foregut. Its development begins with the formation of a dorsal and a ventral pancreatic bud. The dorsal bud grows in the dorsal mesentery and the ventral grows in the ventral mesentery of the duodenum. Later the ventral bud rotates along with the rotation of the duodenum and fuses with the dorsal pancreatic bud. The dorsal pancreatic bud forms the upper part of the * Professor of Anatomy Melaka Manipal Medical College, Manipal University, Manipal, India. * Final year Medical Student, Melaka Manipal Medical College, Manipal University, Manipal, India.