Clinical Challenges - January 2017
What’s your diagnosis?

The diagnosis

The radiographic and pathologic findings and the patient’s clinical presentation were most consistent with autoimmune pancreatitis and IgG4-related sclerosing cholangitis, which are manifestations of IgG4-related disease. IgG4-related disease is a fibroinflammatory condition that has been described in almost every organ system. Elevated serum IgG4 levels suggest this diagnosis, but many times remain normal.1,2 Therefore, a strong clinical suspicion should prompt a biopsy of the affected tissue, which will show a dense lymphoplasmacytic infiltrate organized in a matted and irregularly whorled pattern.2,3 Making a diagnosis requires immunohistochemical confirmation with IgG4 immunostaining of plasma cells.

The patient was started on prednisone followed by azathioprine and experienced a rapid and sustained clinical and biochemical response even after stopping immunosuppressive therapy. After treatment, repeat imaging studies were performed, which showed dramatic improvement in the above-mentioned abnormalities. Abdominal CT showed a decrease in size of the pancreatic head (Figure C) and repeat cholangiogram showed resolution of biliary stenoses (Figure D).

References

1. Oseini, A.M., Chaiteerakij, R., Shire, A.M., et al. Utility of serum immunoglobulin G4 in distinguishing immunoglobulin G4-associated cholangitis from cholangiocarcinoma. Hepatology. 2011;54:940-8.

2. Takuma, K., Kamisawa, T., Gopalakrishna, R., et al. Strategy to differentiate autoimmune pancreatitis from pancreas cancer. World J Gastroenterol. 2012;18:1015-20.

3. Stone, J.H., Zen, Y., Deshpande, V. IgG4-related disease. N Engl J Med. 2012;366:539-51.