View source for WBR0805

{{WBRQuestion
|QuestionAuthor={{Rim}}
|ExamType=USMLE Step 1
|MainCategory=Embryology
|SubCategory=Gastrointestinal
|MainCategory=Embryology
|SubCategory=Gastrointestinal
|MainCategory=Embryology
|SubCategory=Gastrointestinal
|MainCategory=Embryology
|MainCategory=Embryology
|SubCategory=Gastrointestinal
|MainCategory=Embryology
|SubCategory=Gastrointestinal
|MainCategory=Embryology
|SubCategory=Gastrointestinal
|MainCategory=Embryology
|SubCategory=Gastrointestinal
|MainCategory=Embryology
|MainCategory=Embryology
|SubCategory=Gastrointestinal
|Prompt=A 36 year old man with no significant past medical history presents to the emergency department for right upper quadrant abdominal pain and jaundice.  On physical examination, his vital signs show a temperature of 38.5 degrees C (101.3 degrees F), heart rate of 96 bpm, and a blood pressure measuring 118/78 mmHg. Following appropriate work-up, the diagnosis of acute cholangitis is made.  During endoscopic retrograde cholangiopancreatography (ERCP), he is found to have 2 distinct dorsal and ventral pancreatic ducts. Which of the following embryologic processes failed to occur in this patient's incidental finding?
|Explanation=Pancreatic divisum is considered the most common variant of pancreatic ductal configuration that occurs in approximately 10% of the population.  It is caused by failure of fusion of the dorsal and the ventral pancreatic ducts.  Most patients with pancreatic divisum are asymptomatic and the diagnosis is based on incidental findings during ERCP.  Only the minority of patients with pancreatic divisum are symptomatic and generally complain of non-specific recurrent abdominal pain and episodes of pancreatitis.  Although no definitive cause for the symptoms has been confirmed, it is believed that the partial obstruction of pancreatic fluid at the level of the minor papilla causes an elevated pressure within the ducts and leads to pancreatitis. Symptomatic treatment for such patients is endoscopic sphincterotomy.

Educational Objective: 
Pancreatic divisum is the most common congenital variant of pancreatic ductal configuration.  It is caused by the failure of fusion of the distal and ventral pancreatic ducts leading to 2 distinct ducts.

Reference:
Manfrendi R, Costamagna G, Brizi MG, et al. Pancreas divisum and "santorinicele": diagnosis with dynamic MR cholangiopancreatography with secretin stimulation. Radiology. 2000;217:403-408.
|AnswerA=Failed fusion
|AnswerAExp=Pancreatic divisum is caused by failure of fusion of the dorsal and ventral ducts.
|AnswerB=Failed apoptosis
|AnswerBExp=Pancreatic divisum is not due to failed apoptosis.
|AnswerC=Failed differentiation
|AnswerCExp=Pancreatic divisum is not due to failed differentiation.
|AnswerD=Failed proliferation
|AnswerDExp=Pancreatic divisum is not due to failed proliferation.
|AnswerE=Failed recanalization
|AnswerEExp=Pancreatic divisum is not due to failed recanalization.
|RightAnswer=A
|WBRKeyword=pancreatic, divisum, fusion, fuse, ventral, dorsal, duct, ducts, failure of fusion, failed fusion, pancreas, recanalization, differentiation, apoptosis, failure, failed, cholangitis, incidental, finding, fever, jaundice, abdominal, pain
|Approved=No
}}