[IgG4-related systemic disease with autoimmune pancreatitis and lung involvement primarily presenting as pancreatic cancer with pulmonary metastases].

BACKGROUND

After the first case publication using the term "autoimmune pancreatitis" in 1995 and the successful treatment with steroids we now can distinguish between two clinical und histopathological forms of autoimmune pancreatitis. Type 1 autoimmune pancreatitis (AIP) is usually part of an IgG4-related systemic disease. AIP Typ 2 is an IgG4-independent pancreatic disease. For both entities pancreas cancer is the most important differential diagnosis.

CASE REPORT: We report the case of an 82-year-old male patient who primarily presented with obstructive jaundice. Computed tomography (CT) revealed the typical image of a small cancer of the head of the pancreas with pulmonary metastases. After endoscopic drainage of the bile duct a CT-guided biopsy of a pulmonary nodule was performed in which cancer was ruled out. Next the patient was treated with steroids because of "tumour-associated cachexia". In the follow-up the mass in the head of the pancreas like the lung nodules had surprisingly disappeared. In the complete work-up the immune histochemical staining of the lung biopsy revealed subsequently a typical IgG4-associated inflammation. After termination of the therapy the disease relapsed as sclerosing cholangitis.

CONCLUSION

The IgG4-related systemic disease with AIP can present as cancer of the pancreas with lung metastases. Extrapancreatic IgG4-positive histopathology and response to therapy with steroids can help to diagnose the disease in complex clinical presentations.