[A case report of IgG4-related sclerosing disease with lung involvement]

IgG4-related sclerosing disease(IgG4-RSD) is a kind of lymphoplasmacytic disease with multi-organ involvement and is characterized by serum IgG4 elevation and tissue IgG4 positive plasma cell infiltration. Autoimmune pancreatitis, sclerosing cholangitis, sclerosing sialadenitis, retroperitoneal fibrosis and lymphadenopathy make up its main clinical manifestations. This difficult case was a middle-aged female with onset as muiltiple lymph nodes and glands enlargement, including lacrimal gland, salivary glands and pancreas. Meanwhile, repeated examinations of auto-antibodies and serum IgG4 were all negative. The patient didn't respond well to glucocorticoid therapy, and further progressed to rare lung involvement presenting as lung nodule. This complex entity was eventually diagnosed as IgG4-RSD by the support of histopathology evidence of IgG4 immunohistochemistry stain. Though IgG4-RSD has been known for years, it is still underappreciated in China and case reports are scarce. The case report here with literature review is just to enhance the recognition of this disease regarding its pathogenesis, various clinical manifestations, diagnosis and therapy.