Subacute pulmonary granulomatous schistosomiasis: high resolution CT appearances--another cause of the halo sign.

A case of probable acute granulomatous pulmonary schistosomiasis is described with multiple focal opacities on chest radiography and widespread, but predominantly peribronchovascular, nodules with ground-glass halos on high resolution CT (HRCT). The HRCT appearances in early schistosomiasis have not been described previously. Although the features are not diagnostic and may be seen in other conditions, in the appropriate clinical context they may suggest pulmonary involvement in schistosomiasis. The features of pulmonary schistosomiasis in the different stages of infection are discussed. Pulmonary involvement should be suspected in patients with even minor respiratory symptoms when there is a history of exposure to fresh water in endemic areas.