The instance mentioned above illustrates fibrosing mediastinum with narrowing of the superior vena cava. Fibrosing mediastinitis is distinguished by the presence of thick fibroblasts. a non-cancerous and infrequently occurring fibrous tissue in the mediastinum.

This typically affects young age groups, and patients present with symptoms and signs associated with obstruction of critical mediastinal structures. Additionally, the main factor contributing to non-malignant SVC thrombosis is fibrosing mediastinum.

In the majority of cases, the source and pathophysiology are unknown, and linkages to infectious (histoplasmosis, tuberculosis) and noninfectious (immune-related) causes have been theorized.

The diagnosis of fibrosing mediastinitis is almost certain given the patient's prior TB treatment history (treated for disseminated TB involving lung, liver and spleen), multiple mediastinal, hepatic, and splenic parenchymal calcifications, typical imaging findings, as well as bronchoscopically guided biopsy were negative for fungi and acid-fast bacilli while demonstrating chronic inflammation without malignant cells.