Non-IgG4-Related Fibrosing Mediastinitis Diagnosed on Core Needle Biopsy and Treated with Steroids: A Case Study and Review of the Differential Diagnoses.

Fibrosing mediastinitis is an extremely uncommon entity with unknown pathogenesis, and it is more important to rule out malignancy and infection than to delineate between fibrosing mediastinitis and IgG4-related disease. In doing this, we may reasonably initiate a trial of corticosteroids which may prove beneficial, as in this patient. More studies on the pathogenesis of fibrosing mediastinitis are necessary to guide better directed treatments.