Pulmonary schistosomiasis - imaging features

Abstract

Schistosomiasis is a helminthic infection that is endemic in tropical and subtropical regions. Pulmonary involvement can be divided into two categories: acute or chronic compromise. Chronic and recurrent infection develops in persons living or travelling in endemic areas. In the lungs, granuloma formation and fibrosis around the schistosome eggs retained in the pulmonary vasculature may result in obliterative arteriolitis and pulmonary hypertension leading to cor pulmonale. Acute schistosomiasis is associated with primary exposure and is commonly seen in nonimmune travelers. The common CT findings in acute pulmonary schistosomiasis are small pulmonary nodules ranging from 2 to 15 mm and larger nodules with ground glass-opacity halo. Katayama fever is a severe clinical manifestation of acute involvement. We present a case of pulmonary involvement in schistosomiasis and provide a discussion about typical imaging findings in the acute and chronic form.

Keywords: computed tomography; lung disease; parasitic; schistosomiasis.

Figure 1

Egg of schistosoma haematobium showing the characteristic terminal spine. (Magnification factor 500)

Figure 2

Egg of schistosoma mansoni with a characteristic shape and a prominent lateral spine near the posterior end. (Magnification factor 500)

Figure 3

28 y old male with pulmonary schistosomiasis. Chest radiography (pa) showing multiple small pulmonary nodules scattered over both lungs without obvious predilection.

Figure 4

28 y old male with pulmonary schistosomiasis. Chest CT of the upper lungs showing blurred ground glass nodules scattered over both lungs (Siemens Sensation 16. 120 kV, 100 mAs, 16×1.5 mm collimation, slice thickness 3 mm).

Figure 5

28 y old male with pulmonary schistosomiasis. Chest CT of the middle lungs showing ground glass nodules and subpleural consolidation of the left superior lower lobe, both consistent with acute eosinophilic infiltration in the context of acute pulmonary schistosomiasis (Siemens Sensation 16. 120 kV, 100 mAs, 16×1.5 mm collimation, slice thickness 3 mm).

Figure 6

56 y old male with angiostrongyloidosis. Chest CT of another patient with parasitic disease. Upper lungs showing ground glass nodules in peripheral distribution represeting eosinophilic accumulation as an unspecific feature in parasitic lung involvement in the context of Loeffler syndrome (Siemens Sensation 16. 120 kV, 120 mAs, 16×1.5 mm collimation, slice thickness 3 mm).