This 32 year-old male patient had a tooth extraction which was complicated by right submandibular and deep neck space abscess which tracked to the mediastinum. The CT shows mediastinal gas and fluid (arrow), bilateral pleural effusions and pericardial effusion (yellow arrowheads).

Acute mediastinitis is an infection of the mediastinum which is often fulminant and fatal. The majority result from oesophageal perforation (including from primary carcinoma, impacted foreign body, during endoscopy, or spontaneously after vomiting). Other rarer causes are direct extension from adjacent soft tissue spaces (eg retropharyngeal abscess) or as a complication of bronchoscopy. Bacillus anthracis infection may present with severe acute mediastinitis.

Mediastinitis may progress to abscess formation or to the development of fistulae such as oesophagopleural fistulae.

Reference: Fraser and Pare. Diagnosis of Diseases of the Chest W.B.Saunders 1979

Credit: Dr Laughlin Dawes