[IgG4-related disease: a case report].

IgG4-related disease is an inflammatory condition characterized by high levels of IgG4. It affects salivary and lacrimal glands, pancreas, lymph nodes, lungs or kidney. The diagnosis is based on identifying a histological pattern with a dense lymphocyte and plasmacyte infiltration, focal fibrosis or phlebitis, finding more than 10 IgG4 positive cells per high power field and/or IgG4/IgG ratio in plasma higher than 40%.