[IgG4 related disease with exclusive sinonasal involvement: A case report and literature review].

IgG4 related disease (igG4-RD) is a pathological process which integrates a large number of diseases of unknown pathogenesis, considered as being exclusive to many different organs. Diagnosis is established through histological, radiological and serological criteria. Treatment is based on long term corticosteroids; rituximab being used only in refractory cases. It is unusual for this entity to be found exclusively in the head and neck, without systemic involvement; there are only a few reported cases to date. We present a case of a nasosinusal IgG4-RD orbital tumor with paranasal sinus involvement. The accurate diagnosis made early onset corticosteroid treatment possible and the patient is currently asymptomatic.