Abstract
Lymphangiomas are rare benign tumors that result from lymphatic vessel malformations and/or obstructions commonly on the neck and armpits, being rare in the retroperitoneal space. We report a case of a healthy 25-month-old male with a six-month history of abdominal distension and recurrent episodes of diarrhea who was clinically diagnosed with giardiasis. The complementary evaluation showed a cystic formation occupying the whole abdominal cavity and implanted at the abdominal retroactivity. The patient underwent videolaparoscopic surgery. At histopathological and histochemical examinations, the diagnosis of cystic lymphangioma was stated. The report presents a rare case of retroperitoneal lymphangioma, a condition that is frequently misdiagnosed due to its rarity.