Congenital short pancreas

Congenital short pancreas, also known as partial agenesis or hypoplasia of the dorsal pancreas1 is a rare congenital abnormality consisting of the parenchyma and ductal system restricted to the head with some residual dorsal tapering and arborizing ducts communicating with the minor papill.2 Complete pancreatic agenesis is fatal, and only nine possible examples of partial agenesis have been previously reported in adults in the literature.3-10 Three of them were polysplenia syndrome associated with short pancreas, and only six patients with congenital short pancreas with normal situs. Here we present a new case associated with steatorrhoea. CASE REPORT A 43-year-old Chinese woman was admitted to this hospital in November 2005 because of aggravated epigastric pain for one year and vomiting and diarrhea for 4 months. The patient underwent cholecystectomy for acute cholecystitis in September 2004. The symptoms were not alleviated after operation. She complained of recurrent severe pain in the epigastric region, which radiated to the back and was partially relieved by leaning forward. The pain lasted from half an hour up to two hours and was accompanied by diarrhea with undigested food. Between these episodes, she complained of a post-prandial heaviness, sometimes relieved by vomiting. She underwent another laparosopic operation in September 2005 for hiatus hernia, but the symptoms were not alleviated. On admission, a weight loss of 10 kg was recorded. She was diagnosed as an insulin-dependent diabetes 6 years ago with poor glucose control. There was no history of abdominal trauma, abdominal pain, pancreatitis, and no significant family history. Physical examination: body temperature: 37.1°C; blood pressure: 121/78 mmHg. Mild tenderness in upper abdomen but otherwise unremarkable. The endoscopy showed gastric stasis without stenosis or reflux esophagitis. Ultrasonography showed an abnormal echogenic pattern in the head of the pancreas, while the body or tail of pancreas could not be identified. Computerized tomography (CT) (Fig. 1) showed: (1) postoperation change of cholecystoectomy; (2) no pancreas’ body or tail could be identified; (3) dilation of stomach and duodenum. Magnetic resonance imaging (Fig. 2) revealed a short pancreatic duct (the length was 31.63 mm) stretching up and rightward. Plain abdominal film showed incomplete intestinal obstruction. Upper gastrointestinal series confirmed gastric stasis. Normal results were found in colorectal endoscopy, electroencephalogram, normal flow in the color Doppler imaging of hepatic portal vein, superior mesenteric celiac trunk and thoracic aorta. Laboratory examination showed a para-aminobenzoic acid (PABA) excretion test of: 43.0% (normal value > 50.0%). Insulin releasing test: 0 minute serum insulin: 2.00 mIU/L; 60 minutes serum insulin: 5.50 mIU/L; 120 minutes serum insulin: 2.90 mIU/L; 180 minutes serum insulin: 3.60 mIU/L; serum C-peptide assay: 0 minute: 0.80 ng/ml; 60 minutes: 1.70 ng/ml; 120 minutes: 1.30 ng/ml; 180 minutes: 0.99 ng/ml. Oral glucose tolerance test: 0 minute serum glucose: 15.93 mmol/L; 60 minutes serum glucose: 23.12 mmol/L; 120 minutes serum glucose: 19.50 mmol/L; 180 minutes serum glucose: 20.10 mmol/L. Blood tumor marker: CA19-9 (11.16): 49.90 U/ml; (11.22): 52.70 U/ml; (12.7): 55.00 U/ml; Thyroid function test, examination of blood cell, adrenocorticotropic hormone, serum amylase and lipase levels, myocardial enzymes, cardiac troponin-I test, antinuclear antibodies assay, erythrocyte sedimentation rate, c-reactive protein, tuberculosis antibody, purified protein derivative, bacterial culture of stool showed no evidence of abnormality.Fig. 1.: Computerized tomography showing no body or tail of the pancreas that could be identified and the dilation of the stomach and duodenum.Fig. 2.: Magnetic resonance imaging revealing a short pancreatic duct (the length was 31.63 mm) stretched toward to the right above. There is no pancreatic duct that can be seen in the region of the body or tail of the pancreas.DISCUSSION Etiology and pathogenesis The pancreas develops from dorsal and ventral elements, which normally fuse with each other in the second month of the embryonic state. The ventral bud gives rise to a portion of the pancreatic head and to the uncinate process, while the dorsal pancreas is the origin of the pancreatic head, body, and tail.11 Congenital aplasia of the body and tail of the pancreas derived from a defect of the dorsal pancreatic anlage and should not be considered a type of acquired atrophy of these structures.7 Classification Aplasia, or varying degrees of hypoplasia, of the pancreas were classified histologically by Lumb et al into:12 (1) complete, (2) partial: (a) involving both endocrine and exocrine tissue, (b) involving endocrine tissue only, (c) involving exocrine tissue only. Hypoplasia of the pancreas in adults have been found only in the dorsal part of the pancreas, and there have been no reported cases of partial agenesis of the ventral pancreas except a case in infant.10 According to the degree of immaturity of the dorsal pancreas development, hypoplasia of the pancreas is classified clinically into three types (1) total agenesis of the dorsal pancreas; (2) hypogenesis of the body and tail; (3) hypogenesis of the tail. In type 1, the major pancreatic duct can be identified on endoscopic retrograde cholangiopancraphy (ERCP) images, but not the minor pancreatic duct. In types 2 and 3, ERCP images show both major and minor pancreatic ducts communicating with each other, which can be used to rule out pancreas divisum.7 Diagnosis Nowadays, careful scanning and pancreatography can correctly make the diagnosis. In this case, ultrasonography and CT scanning confirmed our diagnosis by revealing the absence of pancreatic tissue in the region of the body and tail of the pancreas. There was no history of abdominal trauma, previous abdominal pain or history of pancreatitis, and the relevant investigations can exclude the pancreatic atrophy secondary to pancreatitis upstream of an obstructed duct. Clinical features It can be an incidental finding in the radiological examination without any symptom.1,9 In the patients described to date, abnormal pain eventually led to the diagnosis being made. The etiology of the abdominal pain of congenital abnormality of the pancreas is unknown and has been presumed to be pancreatitis or autonomic neuropathy similar to that in patients with diabetes mellitus.9 Diabetes presented in 5 of the 9 reported cases; in some cases it substantially preceded the onset of abdominal discomfort and anatomical diagnosis.13 Most patients with congenital short pancreas with normal situs have had diabetes mellitus, occasionally associated with pancreatitis. In contrast, patients with polysplenia short pancreas are not diabetic and have normal amylase levels.3-5,11 Our case revealed that ultrasonography and CT showed no existence of the body and tail of the pancreas, complicated with insulin-requiring diabetes mellitus, which was due to the reduced number of B cells, as the dorsal pancreas contains more A, B, and D cells in the Langerhans islet than in the ventral pancreas.14 In the present case, the glucose tolerance test, serum C-peptide assay and insulin releasing tests showed a poor response of plasma insulin, suggesting that the patient has a small number of B cells.15 It is not sure whether the patient’s steatorrhea contributed to insufficiency of the exocrine function or not, and from various tests i.e. steatorrhea, PABA, triolein, the exocrine pancreatic function was judged to be either normal, borderline,9 or abnormal.10 Pancreatic exocrine dysfunction is probably normal if approximately 10% of the secretory capacity of the pancreas remains.9 In this case, the PABA test showed a slight exocrine pancreatic insufficiency. With good control of the diabetes, the patient’s diarrhea stopped, which suggests that the diarrhea was ascribed to a diabetic autonomic neuropathy. It is also unclear whether congenital short pancreas is accompanied by pancreatitis or not. Calcifying pancreatitis in congenital short pancreas has also been reported.9,10 The other digestive problems, such as gastric stasis and vomiting were also ascribed to a diabetic autonomic neuropathy.8 Investigation Most of the routine laboratory findings were normal; the amylase and lipase levels were also normal. PABA excretion test was judged to be normal, borderline,9 or abnormal.10 Ultrasonography and CT scanning revealed a slightly abnormal head of the pancreas without body or tail being identified. MRI revealed a short branching main pancreatic duct consistent with a ventral pancreas. The pancreatic duct could not be seen at the region of the body and tail of the pancreas. ERCP revealed an abnormal duct configuration considered to be consistent with a ventral pancreas. Injection of contrast into the main papilla resulted in spillage into the duodenum via the accessory papilla. No contrast entered the body of the gland. There was a duct system that communicated with both minor and major papilla.9 Some cases have shown a short and dilated main duct.13 Differential diagnosis Pancreatic atrophy: Congenital short pancreas should be differentiated from pancreatic atrophy, secondary to pancreatitis upstream of an obstructed duct.9 A history of previous abdominal pain, panceatitis, CT scanning, and the amylase level detection can make the differential diagnosis. Tumor of the pancreas: It is also important to differentiate tumor of pancreas from congenital short pancreas. In general, CT scanning shows the density of the head of the pancreas as uniform and no body and tail of the pancreas in congenital short pancreas. Most of the tumors of the head of the pancreas are malignant, which can be accompanied by jaundice. CT shows a tumor of the head of the pancreas causing obstruction of both the pancreatic duct and the common bile duct giving a classic double-duct stricture sign and the existence of the body and tail of the pancreas. Other pancreatic malformations: Congenital short pancreas needs to be differentiated from other pancreatic malformations. The pancreas develops from dorsal and ventral elements. Failure of fusion may result in “pancreas divisum”, present in at least 5% of the population. The rarer annular pancreas occurs when the two parts fuse through a circumferential branch.8 The clinical features of pancreas divisum are similar to the chronic pancreatitis. The entity is usually diagnosed at ERCP: (1) a short but normal “tree-like” ventral segment of pancreatic duct is identified after contrast is introduced through the major papilla, and (2) a patent dorsal system draining the body and tail of the pancreas is delineated by injecting a contrast through the minor papilla. Diagnosis for the annular pancreas is often made by X-ray, which may show 2 areas of gas shadow with air-fluid levels (double-bubble sign) or a dumb-bell shaped shadow. In adults, the diagnosis is often made by radiological demonstration of a hugely dilated first part of the duodenum during a barium study. CT scanning can identify the body and the tail of the pancreas of both pancreas divisum and annular pancreas. Treatments The main goal of the therapy for congenital short pancreas is to relieve symptoms. There is no need to treat the patient without symptoms. Control of the diabetes The digestive problems were ascribed to a diabetic autonomic neuropathy. Due to better control of the diabetes, the patient’s diarrhea stopped.8 Odynolysis Noramidopyrine or tremonium could not relieve the pain. Then the patient was given a combination of promethazine, pethidine, and chlorpromazine. Continuous enteral nutrition through a nasogastric tube was adopted at the same time. The patient responded dramatically with a weight gain of 4 kg and a total disappearance of pain.8 In this case, the patient’s pain was not relieved by pinaverium bromide, scopolamine butylbromide, trimebutine maleate, or tramadol. She was then given a combination of non per os, total parenteral alimentation, gastrointestinal decompression, promethazine, risperidone, paroxetine and mecobalamin. The pain stopped a few days after administration, Sphincterotomy In one reported case accompanied by calcifying pancreatitis, the pancreatic sphincterotomy was then performed on the papilla, which was catheterized from the second duodenum, causing pain relief.8