Radiological appearance of diaphragmatic mesothelial cysts.

Background: Diaphragmatic mesothelial cysts are congenital lesions that derive from coelomic remnants.

Objective: To describe their radiological appearance on US, CT and MRI.

Materials And Methods: Four children (aged 7-14 years) who underwent surgery and for whom there was pathological confirmation of the diagnosis. Five more children (0-12 months old) who were managed conservatively, but for whom there was a high degree of suspicion for this diagnosis.

Results: All lesions presented as a cystic mass between the thoracic wall and the liver, in the right posterolateral costophrenic angle. Some lesions showed subtle evidence of their extrahepatic location.

Conclusions: The radiological findings identified are highly suggestive of diaphragmatic mesothelial cyst.