Acute mediastinitis, mediastinal granuloma, and fibrosing mediastinitis: a narrative review.

Background and Objective: Acute mediastinitis, mediastinal granuloma (MG), and chronic fibrosing mediastinitis (FM) are distinct disease processes affecting the mediastinal structures. These diseases have variable etiologies, management strategies, and outcomes. The purpose of the manuscript is to present a narrative review of these distinct, albeit rare conditions affecting the mediastinum. Methods: We searched various databases such as PubMed and Google Scholar from the last 10 years for the various benign mediastinal disorders we wanted to discuss. Relevant articles that were written in English were shortlisted and used to help write this narrative review. Key Content and Findings: The most common causes of acute mediastinitis are post-operative infection, esophageal perforation, or deep neck space infection originating from the oropharynx. Acute mediastinitis is a life-threatening disease, is difficult to manage and is associated with high morbidity and mortality. MG is usually a sequela of chronic infection or inflammation that has an overall benign course and the possibility of spontaneous resolution. On occasion, an MG can cause pathophysiological consequences due to its mass effect. FM is caused by infectious, inflammatory, or malignant conditions and can also be idiopathic. This condition leads to extensive fibrosis throughout the mediastinum with invasion of mediastinal structures. It is difficult to treat, especially when complications arise from invasion or compression of mediastinal structures, and it carries a poor prognosis. Conclusions: In this review article, we will discuss each of these conditions in more detail, including epidemiology, pathophysiology, clinical features, imaging features, diagnosis, management, and prognosis.