Cerebrospinal fluid hydrothorax without ventriculoperitoneal shunt migration in an infant.

Cerebrospinal fluid (CSF) hydrothorax is a rare complication of a ventriculoperitoneal shunt (VPS), and even rarer in the absence of shunt migration into the thoracic compartment. Because of the limited volume within the thoracic cavity, hydrothorax in infants can rapidly cause severe respiratory distress. The case of an infant with recurrent CSF hydrothorax despite a well-positioned VPS is presented. A ventriculoatrial shunt was successfully performed as the definitive treatment. The absence of ascites or predisposing factors for decreased peritoneal absorption and a false-negative β(2)-transferrin CSF marker are some of the factors that can add to the diagnostic challenge in these patients. This is a potentially life-threatening condition in infants, which should be closely considered in patients with VPS who develop hydrothorax, although diagnosis is not always straight forward. The etiology and pathophysiology of this very rare disease continue to be elusive, and treatment with ventriculoatrial shunt provides good results.