Clinical and imaging spectrum of tuberculosis-associated fibrosing mediastinitis

Fibrosing mediastinitis (FM) is a rare disorder characterized by an excessive fibrotic reaction within the mediastinum, which can result in compression of mediastinal structures. To investigate the clinical and imaging characteristics of TB-associated FM, patients with evidence of TB infection were retrospectively evaluated in this study.

A total of 33 patients with clinically diagnosed FM and evidence of TB infection were selected from the database of two institutional medical centers. Medical records were reviewed to evaluate the clinical disease spectrum, responses to therapy and imaging characteristics.

TB-associated FM showed distinctive infiltrative pattern on chest CT, such as bilateral involvement and hilar predominance. The majority of patients presented with nonspecific respiratory symptoms due to the compression of mediastinal broncho-vascular structures. Echocardiography discovered pulmonary hypertension to various degrees in 60% of patients. Although only a part of patients responded to medical therapy, they seldom showed deterioration during the follow-up.

TB-associated FM shows some specific imaging characteristics, reflecting immune-mediated fibrotic reaction secondary to TB infection. The insidious progression to mediastinal fibrosis after TB infection poses a challenge to the early diagnosis and results in subsequent respiratory dysfunction and pulmonary hypertension.