- (2007) Volume 8, Issue 4
Oya Uygur-Bayramiçli1, Resat Dabak2, Gamze Kiliçoglu3, Can Dolapçioglu1, Derya Öztas1
Departments of 1Gastroenterology and 2Family Medicine, Kartal State Hospital; 3Department of Radiology, Haydarpasa Numune Hospital. Istanbul, Turkey
Received March 9th, 2007 - Accepted May 10th, 2006
Context Agenesis of the dorsal pancreas is a rare entity and might present with various symptoms. We report a case which presented with chronic pancreatitis. Case report The patient presented with epigastric pain and we found dorsal pancreatic agenesis causing chronic pancreatitis. Conclusions Dorsal pancreatic agenesis can be easily diagnosed with new techniques and its association with clinical syndromes can be better understood.
Abdominal Pain; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Pancreatitis, Chronic
During the complex embryologic development of the pancreas, several morphologic anomalies can develop. One of these anomalies is complete agenesis of the dorsal pancreas which is a rare entity and has been reported in the literature only as case reports. This congenital anomaly is accepted mostly as an anatomic variation but it may cause some symptoms such as non-specific abdominal pain and diabetes mellitus [1]. We present a case of dorsal pancreatic agenesis presenting as chronic pancreatitis.
A 44-year-old male patient presented with epigastric pain of a two week duration which worsened after meals. In these two weeks, the patient had lost 4 kg as a result of deceased food intake due to a fear of pain; he also had loose stools. The patient said that he had had three similar pain episodes in the last two years. The past medical records of the patient revealed that he had had mild hyperamylasemia and leukocytosis during those episodes, but they resolved spontaneously after one to two weeks and the patient had not received any treatment. Abdominal ultrasound was said “to be normal” but the images were not available. On physical examination, everything was normal except for abdominal distension. There was no family history of pancreatitis or diabetes and he himself did not have a history of diabetes. He did not drink alcohol or smoke and he did not use any drugs on a regular basis. The biochemical evaluation of the patient revealed hyperamylasemia (250 IU/L; reference range: 30-115 IU/L), leukocytosis (12,000 mm-3; reference range: 4,000-11,000 mm-3) and a mild elevation of fasting plasma glucose (135 mg/dL; reference range: 80-115 mg/dL). A Van de Kamer test, transaminase, alkaline phosphatase, gamma glutamyltransferase, bilirubin, CRP, lipase and CA 19- 9 levels were normal. An abdominal ultrasound was performed which showed a large dense pancreatic head. An upper abdominal MRI and MRCP were carried out with the suspicion of a pancreatic malignancy. T2-weighted axial MRI images demonstrated that the pancreatic head and neck were normal in size and shape; however, the body and tail were inexistent. At MRCP, the major pancreatic duct was short and the dorsal duct could not be visualized. These findings were compatible with the diagnosis of dorsal pancreatic agenesis (Figure 1). The patient was diagnosed as having chronic relapsing pancreatitis based on the recurrent clinical symptoms and laboratory values. We could not identify any toxins, or metabolic or autoimmune disorders which may have caused chronic pancreatitis. The pain resolved after 10 days on a low-fat diet; his diabetes was also controlled with diet. The patient had two more episodes of epigastric pain and hyperamylasemia in the following 12 months but they also resolved spontaneously.
Figure 1. Abdominal MRCP showing a short major pancreatic duct and no visualized dorsal duct.
The pancreas is formed by ventral and dorsal endodermal buds. At the 6-7th week of gestation the ventral pancreas fuses with the dorsal pancreas and then both of these buds form the main pancreatic duct. During this complex development, congenital abnormalities can occur.
Complete agenesis of the pancreas and agenesis of the ventral pancreas are not compatible with life [2]. Partial agenesis of the dorsal pancreas is another anomaly which has been reported in 14 cases between 1913 and 1999 [1]. The differential diagnosis of dorsal pancreatic agenesis must be made between pancreas divisum and autodigestion due to chronic pancreatitis. The chief complaint of the patients with dorsal pancreatic agenesis is abdominal pain which is possibly related to the underdevelopment of the papillary muscle [3]. Most of them also have diabetes mellitus probably because most of the islet cells are located in the pancreatic body and tail [1]. Absence of the dorsal pancreas may co-exist together with polysplenia syndrome [4] and may also cause acute pancreatitis [5, 6] and chronic pancreatitis [3].
In the literature, there is a case of pancreatic adenocarcinoma associated with dorsal agenesis [7] and also a familial case of agenesis [8].
Two possible mechanisms may play a role in the pathogenesis of pancreatitis in these patients, namely sphincter of Oddi dysfunction [9] and hypertrophy of the remnant ventral gland with higher intrapancreatic duct pressures [10].
Distal pancreatic agenesis involves the body and tail, generally starting from the midline. The situation may be distinguished from fatty infiltration of pancreatic tissue by the presence of volume loss and intestinal loops filling the location of the presumed distal pancreas. Namely,, if fatty infiltration had taken place, there would have been fatty tissue in the expected location of the distal pancreas, . Further discrimination may only be possible at pathological examination which would demonstrate the presence of islet cells within the excised tissue. However, this patient was not operated on; therefore, pathological evaluation was not possible and diagnosis has to be established based on imaging findings alone.
The most common cause of chronic pancreatitis is alcohol ingestion followed by tropical, hereditary, metabolic, autoimmune pancreatitis. There is a subclass which is defined as “anatomic” chronic pancreatitis, namely, a pancreatitis associated with obstructive pancreatitis, pancreas divisum, post-traumatic pancreatic duct scars and periampullary duodenal wall cysts [11]. Chronic pancreatitis due to dorsal pancreatic agenesis can also be defined as “anatomic” pancreatitis which probably causes an impairment of pancreatic secretion and higher intraductal pressures in the dense ventral part. Its diagnosis requires a high index of suspicion. Before the use of modern imaging techniques, the diagnosis was only made by autopsy or at surgery. Now, abdominal US, CT, ERCP, MRCP and EUS can be used for a diagnosis [12]. EUS seems to be a much more sensitive and noninvasive method in the diagnosis of pancreatic disease in comparison to other diagnostic modalities [13].
Complete agenesis of the dorsal pancreas will be able to be diagnosed much more easily with these techniques in the future [12, 14], and its association with clinical syndromes will be better understood.
The authors have no potential conflicts of interest
