Approach Considerations
If pancreatitis is suspected, amylase and lipase levels should be measured, as they may support a clinical diagnosis. However, these laboratory test findings alone are not reliable or cost effective as a screening tool, and the magnitude of enzyme elevation does not correlate with the severity of pancreatic injury. [5]
Ultrasonography and computed tomography (CT) scanning are the preferred imaging modalities used to diagnose and follow the course of pancreatitis and pancreatic pseudocysts.
Laboratory Studies
Amylase levels
Elevated serum or urine amylase levels aid in the diagnosis of pancreatitis and peak 48 hours after onset, although 10-15% of patients with pancreatitis may have levels within the reference range. Serum amylase levels are typically elevated for as long as 4 days—although amylase levels can be elevated in patients with other abdominal conditions, the levels are typically not as high as those found in patients with pancreatitis.
Lipase levels
Serum lipase is more specific than amylase for acute pancreatitis, and typically, lipase levels remain elevated 8-14 days longer than amylase levels. Serum lipase levels can also be elevated in patients with other diseases or conditions; therefore, all laboratory results should be evaluated in the context of the clinical presentation. [6]
Other
Other laboratory abnormalities found in patients with pancreatitis may include coagulopathies, leukocytosis, hyperglycemia, glucosuria, hypocalcemia, hyperbilirubinemia, and elevated gamma glutamyl transpeptidase.
Urinary levels of trypsin activator peptide (TAP) may help determine the severity of the pancreatitis.
As many as 20% of children who present with acute pancreatitis develop severe disease that carries an increased morbidity, longer hospitalization, and need for aggressive medical management. A retrospective study showed that malnourished children were more likely to experience a protracted hospitalization independent of all the conventional biochemical parameters associated with an increased risk of disease severity in adults, including hypertriglyceridemia, ethnicity, or history of hepatobiliary disease. [7] In that study, most children with severe malnutrition had comorbid conditions, including cerebral palsy and encephalopathy, that could have masked the typical early clinical symptoms of acute pancreatitis.
One study provided a prognostic tool that may be used clinically to predict the severity of acute pancreatitis in children. [7] In that study, a predictive model based on a high serum lipase level (>19 the upper limit of normal) and a low albumin and white blood cell count was associated with an increased risk of morbidity. The authors concluded that the application of these three parameters in clinical practice may help pediatricians to identify those patients who are most at risk in developing severe pancreatitis and can thus help direct a more aggressive clinical management strategy.
Imaging Studies
Ultrasonography is the primary screening tool for evaluation of the pediatric pancreas, due to the absence of ionizing radiation and ability to image without sedation. Computed tomography (CT) scanning may be better suited for evaluation of chronic pancreatitis and its complications, pancreatic trauma, and neoplastic conditions and is often used to further evaluate abnormalities found on ultrasonography. Magnetic resonance imaging (MRI) is another modality to diagnose pancreatitis, providing tissue characterization and high-contrast imaging of the pancreatic duct without the use of invasive instrumentation or ionizing radiation. [8, 9]
Ultrasonography
Ultrasonography findings may include a focally or diffusely enlarged, hypoechoic, sonolucent, or edematous pancreas; dilated pancreatic ducts; a pancreatic mass; a fluid collection or peripancreatic fluid; an abscess; or a pseudocyst demonstrated as a well-defined, hypoechoic mass, which may be multilocular (see the image below).
Pediatric Pancreatitis. This real-time ultrasonogram of the abdomen, with attention to the right upper quadrant, reveals a loculated fluid collection in the hilum of the liver. This is compatible with a pancreatic pseudocyst. The differential diagnosis includes a large choledochal cyst.
CT scanning
CT scan findings include an enlarged gland with ill-defined margins; peripancreatic fluid; areas of decreased or enhanced density; or pseudocysts with a well-defined wall or capsule and central area of low attenuation (see the following images). CT scanning is a better modality for evaluating presence and extent of pancreatic necrosis and inflammation of peripancreatic fat.
Of note, findings on imaging studies initially appear normal in 20% of children with acute pancreatitis.
Pediatric Pancreatitis. Computed tomography (CT) scan of the abdomen in a child with traumatic pancreatitis. The fluid collection adjacent to the pancreas will become a pseudocyst. Note that the pancreas is lacerated, nearly cut in half, by the force of the abdominal trauma. Also, note the typical location of this injury in relation to the vertebral column.
Pediatric Pancreatitis. Computed tomography (CT) scan of a young man who was referred after 2 weeks into his second bout of severe acute pancreatitis. Gravely ill, he had fever and leukocytosis as well as hypotension requiring pressors and respiratory distress requiring mechanical ventilation. His abdominal CT scan shows severe acute pancreatitis. A percutaneous drain was placed in the dominant fluid collection to establish drainage while he was given imipenem/cilastatin, which stabilized his condition.
Pediatric Pancreatitis. Computed tomography (CT) scan of a patient initially seen for recurrent abdominal pain. An esophagogastroduodenoscopy (EGD) showed a submucosal nodule in the antrum, which prompted a referral to another center, with a request for endoscopic ultrasonography and polypectomy. Because the endoscopic ultrasonogram was indeterminate, a polypectomy was attempted. That evening, the patient developed progressively severe epigastric abdominal pain radiating to the back and presented to an emergency department. She had a leukocytosis and a mild elevation of her lipase and was admitted with a diagnosis of pancreatitis. This CT scan of her abdomen shows circumferential hypodense thickening of her antrum, with a normal-appearing pancreas. A small portion of pancreatic tissue was later identified as pancreatic rectitis in the pathology specimen.
ERCP and MRCP
Endoscopic retrograde cholangiopancreatography (ERCP) is essential for evaluation of pancreatic and biliary anomalies. ERCP can aid in the diagnosis of various ductal abnormalities or obstructions and may serve as a therapeutic intervention (ie, sphincterotomy, stent placement) (see the images below). Magnetic resonance cholangiopancreatography (MRCP) is a noninvasive alternative to ERCP but lacks therapeutic capabilities.
Pediatric Pancreatitis. Familial adenomatous polyposis syndrome in a patient with persistent pancreatitis due to a partially obstructing ampullary adenoma. The pancreatogram shown here reveals a very prominent ductal system. Because the patient had undergone several previous abdominal operations, she opted to have an endoscopic ampullectomy.
Pediatric Pancreatitis. In this radiograph from the same patient as in the previous image, it can be seen that stents were placed into the biliary and pancreatic ductal systems following ampullectomy. The smoldering pancreatitis resolved within a week, the stents were subsequently removed, and the patient participated in an endoscopic surveillance program, with no recurrence at the time of this article's publication.
Pediatric Pancreatitis. Recurrent pancreatitis associated with pancreas divisum in an elderly man. This pancreatogram of the dorsal duct shows a distal stenosis with upstream chronic pancreatitis. After the stenosis was dilated and stented, the patient's pain resolved, and he improved clinically during 1 year of stent exchanges on a quarterly basis. Follow-up computed tomography (CT) scans showed resolution of an inflammatory mass. Although ductal biopsies and cytology were repeatedly negative, pain and pancreatitis returned when the stents were removed. The patient developed duodenal outflow obstruction and was sent to surgery; a Whipple procedure revealed a periampullary adenocarcinoma (of the minor papilla).
Radiography
Roentgenography may demonstrate nonspecific findings ranging from a distended loop of small intestine (ie, sentinel loop), calcifications, radio-opaque gallstones, dilatation of the transverse colon (ie, cutoff sign), ascites, peripancreatic extraluminal gas bubbles, ileus, left-sided basal pleural effusion, and blurring of the left psoas margin to pancreatic calcifications from chronic or recurrent pancreatitis.
Histologic Findings
Acute pancreatitis is characterized by enzymatic necrosis and inflammation of the pancreas. Focal areas of fat necrosis are interspersed with areas of interstitial hemorrhage secondary to destruction of blood vessels. In severe cases, large, blue-black hemorrhagic foci are interspersed with yellow-white chalky areas of fat necrosis.
Chronic pancreatitis is characterized by irreversible destruction of the pancreatic parenchyma and subsequent replacement with fibrous tissue. Histologic features include intraglandular fibrosis, acinar cell destruction, lymphocytic infiltration, and pancreatic duct obstruction. The pancreatic ducts are dilated and obstructed with protein plugs in their lumens. Grossly, the gland is hard.
Pancreatic pseudocysts are localized collections of pancreatic secretions walled off by granulation tissue that lack a true epithelial lining. The stomach, duodenum, small bowel, colon, or omentum may abut or form part of the pseudocyst capsule.
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Pediatric Pancreatitis. This computed tomography (CT) scan of the abdomen in the region of the pancreas demonstrates a large well-marginated cystic structure that represents a pancreatic pseudocyst.
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Pediatric Pancreatitis. This real-time ultrasonogram of the abdomen, with attention to the right upper quadrant, reveals a loculated fluid collection in the hilum of the liver. This is compatible with a pancreatic pseudocyst. The differential diagnosis includes a large choledochal cyst.
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Pediatric Pancreatitis. Flow diagram for suspected acute pancreatitis . Etiologic factors and forms of acute pancreatitis and Ranson criteria are reviewed. ABG = arterial blood gas; Alk phos = alkaline phosphatase; ALT = alanine transaminase; AST = aspartate aminotransferase; BUN = blood urea nitrogen; CBC = complete blood cell count; Cr, creat = creatinine; ERCP = Endoscopic retrograde cholangiopancreatography; Gluc = glucose; lab = laboratory; LDH = lactate dehydrogenase; PO2 = partial pressure of oxygen; SBP = systolic blood pressure; and T bili = total bilirubin.
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Pediatric Pancreatitis. Flow diagram for mild pancreatitis. Favorable prognostic signs and medical management for acute pancreatitis, as well as studies used for acute pancreatitis. NPO = nothing by mouth; RUQ = right upper quadrant.
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Pediatric Pancreatitis. Prognostic indicators for severe pancreatitis and flow diagram for intensive care unit (ICU) management. BUN = blood urea nitrogen; CT = computed tomography; NG = nasogastric; and O2 = oxygen; paO2 = partial pressure of oxygen in arterial blood.
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Pediatric Pancreatitis. Flow diagram for diagnosis and treatment of necrotizing pancreatitis. CT = computed tomography; Tx = treatment.
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Pediatric Pancreatitis. Flow diagram for treatment of and studies used for pancreatic pseudocysts. ERCP = Endoscopic retrograde cholangiopancreatography
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Pediatric Pancreatitis. Flow diagram for management of idiopathic recurrent pancreatitis. Etiologies for acute pancreatitis. CBD = common bile duct; ERCP = Endoscopic retrograde cholangiopancreatography
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Pediatric Pancreatitis. Flow diagram for management of pancreatic abscess. Definition of an abscess.
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Pediatric Pancreatitis. A patient with acute gallstone pancreatitis underwent endoscopic retrograde cholangiopancreatography (ERCP). The cholangiogram showed no stones in the common bile duct and multiple small stones in the gallbladder. In this image, the pancreatogram shows narrowing of the pancreatic duct in the area of the genu, the result of extrinsic compression of the ductal system by inflammatory changes in the pancreas.
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Pediatric Pancreatitis. Abdominal computed tomography (CT) scan from the same patient as in the previous image showing pancreatic enlargement and peripancreatic fat stranding. The gallstones are not visible.
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Pediatric Pancreatitis. Pancreas divisum associated with minor papilla stenosis causing recurrent pancreatitis. Because pancreas divisum is relatively common in the general population, it is best regarded as a variant of normal anatomy and not necessarily as a cause of pancreatitis. In this case, note the bulbous contour of the duct adjacent to the cannula. This appearance has been termed a santorinicele. A dorsal duct outflow obstruction is the probable cause of pancreatitis when a santorinicele is present and associated with a minor papilla that accommodates only a guidewire.
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Pediatric Pancreatitis. Normal-appearing ventral pancreas in a patient with recurrent acute pancreatitis. The dorsal pancreas (not pictured) showed evidence of chronic pancreatitis.
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Pediatric Pancreatitis. Computed tomography (CT) scan of the abdomen in a child with traumatic pancreatitis. The fluid collection adjacent to the pancreas will become a pseudocyst. Note that the pancreas is lacerated, nearly cut in half, by the force of the abdominal trauma. Also, note the typical location of this injury in relation to the vertebral column.
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Pediatric Pancreatitis. Computed tomography (CT) scan of a young man who was referred after 2 weeks into his second bout of severe acute pancreatitis. Gravely ill, he had fever and leukocytosis as well as hypotension requiring pressors and respiratory distress requiring mechanical ventilation. His abdominal CT scan shows severe acute pancreatitis. A percutaneous drain was placed in the dominant fluid collection to establish drainage while he was given imipenem/cilastatin, which stabilized his condition.
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Pediatric Pancreatitis. Endoscopic retrograde cholangiopancreatography (ERCP) in the same patient as in the previous image excluded suppurative cholangitis and established the presence of annular pancreas divisum. The dorsal pancreatogram showed extravasation into the retroperitoneum, and a sphincterotomy was performed on the minor papilla. As shown in this radiographic film, a pigtailed nasopancreatic tube was then inserted into the dorsal duct and out into the retroperitoneal fluid collection. The other end of the tube was attached to the bulb suction and monitored every shift.
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Pediatric Pancreatitis. While percutaneous drains removed loculated fluid collections elsewhere in the abdomen in the same patient as in the previous image, the nasopancreatic tube contained the retroperitoneal fluid collection. One week later, the retroperitoneal fluid collection was much smaller, as shown in this radiographic film (the image is reversed in the horizontal direction). By this time, the patient was off pressors and was ready to be extubated.
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Pediatric Pancreatitis. In the same patient as in the previous image, 4 months later, after the pseudocyst was converted into a pseudocystogastrostomy using minimally invasive techniques, the pancreatogram revealed the more proximal pancreatic duct.
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Pediatric Pancreatitis. In the same patient as in the previous image, a guidewire was placed into the dorsal duct, crossed the stenotic area, and advanced into the proximal duct. A dilating catheter was then advanced over the wire to enlarge the stenosis. The duct was subsequently stented.
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Pediatric Pancreatitis. Six months after severe acute pancreatitis, the same patient as in the previous image remained symptom free and was living independently. As shown in this follow-up abdominal computed tomography (CT) scan, minimally invasive techniques were successful in removing the pockets of infection, restoring the integrity of the pancreatic ductal system. These techniques also preserved the endocrine function of the pancreas, and at the time of this follow-up, the patient had no evidence of diabetes mellitus.
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Pediatric Pancreatitis. Familial adenomatous polyposis syndrome in a patient with persistent pancreatitis due to a partially obstructing ampullary adenoma. The pancreatogram shown here reveals a very prominent ductal system. Because the patient had undergone several previous abdominal operations, she opted to have an endoscopic ampullectomy.
-
Pediatric Pancreatitis. In this radiograph from the same patient as in the previous image, it can be seen that stents were placed into the biliary and pancreatic ductal systems following ampullectomy. The smoldering pancreatitis resolved within a week, the stents were subsequently removed, and the patient participated in an endoscopic surveillance program, with no recurrence at the time of this article's publication.
-
Pediatric Pancreatitis. Recurrent pancreatitis associated with pancreas divisum in an elderly man. This pancreatogram of the dorsal duct shows a distal stenosis with upstream chronic pancreatitis. After the stenosis was dilated and stented, the patient's pain resolved, and he improved clinically during 1 year of stent exchanges on a quarterly basis. Follow-up computed tomography (CT) scans showed resolution of an inflammatory mass. Although ductal biopsies and cytology were repeatedly negative, pain and pancreatitis returned when the stents were removed. The patient developed duodenal outflow obstruction and was sent to surgery; a Whipple procedure revealed a periampullary adenocarcinoma (of the minor papilla).
-
Pediatric Pancreatitis. Computed tomography (CT) scan of a patient initially seen for recurrent abdominal pain. An esophagogastroduodenoscopy (EGD) showed a submucosal nodule in the antrum, which prompted a referral to another center, with a request for endoscopic ultrasonography and polypectomy. Because the endoscopic ultrasonogram was indeterminate, a polypectomy was attempted. That evening, the patient developed progressively severe epigastric abdominal pain radiating to the back and presented to an emergency department. She had a leukocytosis and a mild elevation of her lipase and was admitted with a diagnosis of pancreatitis. This CT scan of her abdomen shows circumferential hypodense thickening of her antrum, with a normal-appearing pancreas. A small portion of pancreatic tissue was later identified as pancreatic rectitis in the pathology specimen.
