[Protein-losing enteropathy caused by a thoracic cyst].

A case of gastrointestinal protein loss in a 58-year-old man presenting with peripheral oedema and low levels of serum proteins is presented. Measurement of gastrointestinal protein loss with 111Indium-labelled transferrin showed a protein loss of 12.5% over 96 hours. Capsule endoscopy showed villous lymphangiectasia and it was assumed that the protein loss was secondary to a large left-sided thoracic cyst obstructing the thoracic lymph drainage. The patient improved following surgical removal of the cyst.