 This paper presents a case study of a 63-year-old male patient who was diagnosed with Kuttner's tumor, also known as sclerosing chronic pancreatitis. He experienced symptoms such as epigastralgia and elevated serum lipase levels, leading to a computed tomography scan of his abdomen revealing a bulky mass of the pancreas. Biopsies were taken from the pancreas, showing massive infiltrations of lymphocytes and plasma cells. This led to a diagnosis of Kuttner's tumor, and the patient was treated with surgery and chemotherapy. One year later, the patient developed sickest syndrome and progressive renal failure. Immunoassays confirmed hypocomplementemia and a renal biopsy showed interstitial inflammation with lymphocyte and plasma cell infiltration. These results were consistent with IgG4-related disease and further testing confirmed this diagnosis. The patient was then successfully treated for hypocomplementomic tubulointerstitial nephritis. This article was authored by Davide Ralla, Diego Bellino, Giancarlo Paloso, and others. We are article.tv, links in the description below.