Chylopericardium presenting as cardiac tamponade secondary to mediastinal lymphangioma

Mediastinal lymphangioma is a rare entity and chylopericardium is a rare form of pericardial effusion. We report a case of acute chylous cardiac tamponade due to a cervicomediastinal lymphangioma in a one-year-old boy. A chest x-ray revealed marked cardiac enlargement and echocardiography showed massive pericardial effusion. Emergency surgery was performed whereby a pericardial window was created, followed by excision of the lymphangioma.