Presentation
Vomiting and epigastric pain of several days of evolution. She brings an abdominal ultrasound showing an allithiasic gallbladder.
Patient Data
The T2-weighted images in the coronal plane show the inflammatory phenomena surrounding the cephalic portion of the pancreas and the loss of the acinar pattern of the parenchyma in this sector, interpreted as acute pancreatitis.
In the weighted T2FS, T1FS and T1-enhanced images, pancreatic tissue is observed completely surrounding the duodenum like a ring.
The 3D reconstructions obtained from the MR cholangiopancreatography sequence show a caliber change in the duodenum over the Vater's ampulla.
Case Discussion
Annular pancreas is an uncommon congenital anomaly.The presentation in adults differs from that in children.
A lot of adults patients with annular pancreas are asymptomatic. When symptomatic, the presentation is usually in the third to sixth decade with abdominal pain, postprandial fullness, vomiting, upper gastrointestinal bleeding from peptic ulceration, acute or chronic pancreatitis, or in rare instances, biliary obstruction.
The pancreas develops from a single dorsal and two ventral buds since in the fifth week of gestation. The two ventral buds rapidly fuse. By the seventh gestational week, expansion of the duodenum causes the ventral bud to rotate and pass behind the duodenum from right to left and fuse with the dorsal bud.
Annular pancreas results from failure of the ventral bud to rotate with the duodenum, resulting in envelopment of the duodenum. This can be complete or incomplete.