IgG4-Producing MALT Lymphoma in the Renal Hilum

IgG4-related disease is diagnosed when both the elevation of the serum IgG4 level and invasion of IgG4-positive interstitial cells and sclerosis to a tumor are noted. Some cases have demonstrated malignant disease. In the head and neck lesion in particular, IgG4-producing mucosa-associated lymphoid tissue (MALT) lymphoma has arisen during the treatment of IgG4-related disease. We herein report the first case of IgG4-producing MALT lymphoma...