Surgical treatment for a patient with immunoglobulin G4-related lung disease.

Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune fibroinflammatory disease, and isolated lung disease is a rare phenomenon. IgG4-RD frequently mimics primary pulmonary malignancy. It has been described in association with malignancies, including lung cancer, but it remains unclear if it increases the risk of malignancy. We report the case of a patient who had a left lower lobectomy after relapse while receiving corticotherapy. The pathological findings confirmed the diagnosis of IgG4-RD. After 2 months, the thoracic computerized tomography scan showed an important left pleural effusion that could be a consequence of the recent intervention or a relapse of IgG4-RD.