Which imaging finding is associated with inhalational anthrax?

• A. Pleural effusion
• B. Pulmonary nodules
• C. Ground-glass opacities
• D. Mediastinal widening on imaging

Answer: (D)

Inhalational anthrax classically presents with mediastinal widening on chest imaging. This happens because the inhaled spores germinate in the lungs and trigger hemorrhagic mediastinitis and edema in the mediastinal tissues and lymph nodes. The result is an enlarged, expanded mediastinal silhouette that can be seen on chest X-ray or CT. Pleural effusions can occur as well, but the finding that best distinguishes this disease on imaging is the widening of the mediastinum. Pulmonary nodules or ground-glass opacities are not the characteristic pattern for inhalational anthrax and are more typical of other infections or inflammatory processes. Understanding this mediastinal widening helps point toward inhalational anthrax in the appropriate clinical context.