[A case of systemic IgG4-related disease with a middle-posterior mediastinal lesion].

A 62-year-old Japanese man visited our hospital for the examination of a middle-posterior mediastinal lesion noted on a chest CT image. Magnetic resonance imaging (MRI) showed swelling of the hypophysis, bilateral orbital muscles and bilateral lacrimal and submandibular glands. CT subsequently showed a middle-posterior mediastinal lesion, centrilobular nodules in the lung fields, swelling of the pulmonary hilar lymph nodes and soft tissue tumor around the bilateral ureteropelvic junctions. The patient's serum IgG4 level was elevated, and biopsy specimens from the lacrimal gland showed abundant IgG4-positive plasma cells. These findings were consistent with systemic IgG4-related disease. Following steroid treatment, the lesions reduced. To the best of our knowledge, there are only 2 case reports regarding systemic IgG4-related disease accompanied with a middle-posterior mediastinal lesion.