Pulmonary zygomycosis: CT appearance

We describe the CT appearance of pulmonary zygomycosis (mucormycosis), an opportunistic infection typically occurring in immunocompromised patients.

Eight patients with pulmonary zygomycosis imaged with CT were reviewed, seven at initial diagnosis and one with a subsequent complication. The appearance, number, and location of pulmonary lesions and the presence of pleural effusions and extrapulmonary involvement were assessed. Rim enhancement, air bronchograms, the halo sign, air crescent sign, cavitation, and central low attenuation suggesting necrosis were recorded.

There were 14 nodules and 5 areas of mass-like or wedge-shaped consolidation. Pleural effusion was present in five patients, halo sign in three, central low attenuation in two, and cavitation in one. In the affected lobe 13 of 14 nodules and all consolidations were posterior. Of 19 lesions 16 (84%) were confined to the upper lobes, with 3 in the superior segment of a lower lobe. Endobronchial disease with lobar collapse was the only manifestation in one patient. Major complications were direct spinal invasion in one patient and multiple pulmonary artery pseudoaneurysms in another patient.

In the appropriate clinical circumstance, nodules or mass-like or wedge-shaped consolidation, especially posteriorly in the upper lobes of the lung, should suggest zygomycosis. Endobronchial zygomycosis is less common.