Image of the Month:
David M. Warshauer, Section Editor
Article Outline
Question: A 43-year-old Pakistani man presented with a 5-week history of painless jaundice, lethargy, and pruritus. He had noticed his urine had become dark, and his stools were pale. In addition, he had lost almost 14 kilograms in weight in the preceding 2 months. He had been a resident of the United Kingdom for 13 years, and he denied any recent foreign travel. He had no other past medical history of note. There was no history of significant alcohol consumption. Physical examination revealed that he was deeply jaundiced, but there were no other clinical findings.
Laboratory tests showed a normal full blood count, urea and electrolytes, glucose, and amylase. Liver function tests were in keeping with an obstructive jaundice, with a bilirubin of 419 mmol/L (range, 3–15), alkaline phosphatase of 1026 IU/L (range, 100–300), and an alanine transaminase of 46 IU/L (range, 5–35). His synthetic liver function was preserved. A full liver etiology screen was negative, with the exception of a weakly positive antinuclear antibody, and a polyclonal increase in gamma globulin.
His CA 19.9 levels were normal (<33 U/mL). An abdominal ultrasound scan showed intra- and extra-hepatic duct dilatation, an enlarged gallbladder containing bile and sludge, and an enlarged, hypoechoic pancreas. Abdominal computed tomography (Figure A) confirmed biliary dilatation and a uniformly swollen pancreas (labeled 1), with a patchy parenchymal pattern on contrast enhancement. Endoscopic retrograde cholangiopancreatography (Figure B) was undertaken with a view to placement of a stent to relieve the jaundice and pruritus. The pancreatic duct is labeled 2. In addition, a 1.5-cm stenosis in the intrapancreatic common bile duct was successfully stented. Brushings did not reveal malignant cells. Endoscopic ultrasonography was undertaken (Figure C); the pancreas is labeled 3. Fine needle aspiration was performed at the time, but only mixed inflammatory cells were observed.
What is the diagnosis?
Look on page 1141 for the answer and see the Gastroenterology website (http://www.gastrojournal.org) for more information on submitting your favorite image to Image of the Month.
Answer to the Image of the Month Question (page 785): Autoimmune Pancreatitis
A case of pancreatitis associated with hypergammaglobulinemia was reported as early as 1965,1 but autoimmune pancreatitis has only recently been recognized as a distinct, and rare, clinical entity. The disease mainly occurs in elderly males and is characterized clinically by painless, obstructive jaundice with few other symptoms. For this reason, it can be extremely difficult to differentiate from carcinoma of the head of the pancreas. Patients may undergo unnecessary pancreaticoduodenectomy because of failure to recognize the condition.
Diagnosis can be achieved by thorough investigation. On computed tomography, the pancreas shows delayed enhancement, and, as noted in our patient, a low density rim surrounding the pancreas has been described. This rim presumably acts as a barrier to leakage, explaining the complete lack of peripancreatic fluid or other features of inflammatory change usually seen with pancreatitis. Irregular narrowing of the pancreatic duct, and stenosis of the lower common bile duct at ERCP are also well recognized. Ultrasonography reveals an enlarged hypoechoic pancreas with bright spots (Figure C). Histopathology reveals pancreatic fibrosis with lymphocytic infiltration. These have been characterized immunohistochemically, and they have shown to be CD4- and CD8-positive T lymphocytes and IgG4-positive plasma cells.2 Indeed, increased levels of IgG, particularly IgG4, have been shown to occur in up to 90% of patients with autoimmune pancreatitis.3 The clinical and radiological findings tend to respond dramatically to steroid therapy.
IgG subclass levels were requested in our patient, and the IgG4 levels were grossly elevated at 12.7 g/L (0.08–1.4). The patient was begun on oral steroids, and his liver function returned to normal, with simultaneous improvement of the radiological abnormalities shown in Figure D of the body of the pancreas, and Figure E of the head and neck area (the gastroduodenal artery is labeled 4, and the biliary stent 5).
His biliary stent was removed and his steroid dose was gradually tapered, with ongoing monitoring of the liver function tests, with a view to commencement of immunosuppressant therapy with azathioprine.
References
- . Chronic inflammatory sclerosis of the pancreas—an autonomous pancreatic disease . Am J Dig Dis . 1961;6:688–698
- . Close relationship between autoimmune pancreatitis and multifocal fibrosclerosis . Gut . 2003;52:683–687
- . High serum IgG4 concentrations in patients with sclerosing pancreatitis . N Engl J Med . 2001;344:732–738
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PII: S0016-5085(05)01556-8
doi:10.1053/j.gastro.2005.07.048
© 2005 American Gastroenterological Association. Published by Elsevier Inc. All rights reserved.
