[Immunoglobulin G4( IgG4)-related Fibrosing Mediastinitis Localized in the Retrosternal Area:Report of a Case].

An 84-year-old man was referred to our out-patient clinic with an elongated mass localized to the retrosternal area that was incidentally identified by computed tomography. On 18F-fluorodeoxyglucose-positron emission tomography, this lesion showed intense tracer uptake. Thus, a surgical biopsy under thoracoscopy was performed. Histological examination revealed dense fibrous tissue associated with inflammatory cell infiltration. The...