[Giant mesocolic cystic lymphangioma: A treacherous prenatal presentation. Case report].

Cystic lymphangiomas are usually located in the neck region. Less frequently, they can be found in the abdomen. In those cases, pre- and neonatal diagnosis is extremely difficult. We report on the case of a giant mesocolic cystic lymphangioma, diagnosed at birth, in a child who had been monitored during the prenatal period for what was believed to be a digestive dilatation. The progression was marked by excellent tolerance despite a complete lack of regression in the first 10 months of life. The authors discuss the prenatal signs that should suggest this diagnosis and an MRI, as well as management during the 1st year of life.