Lymphatic malformation is a rare congenital lesion caused by lymphatic abnormality. Herein is a case of extensive pediatric lymphatic malformation involving almost entire neck from skull base to mouth floor. Surgical excision of the huge mass was performed without tracheostomy. Repeated attempts on post-operative extubation resulted in cyanosis and apnea due to narrow postlingual space. Hyoid suspension was performed to improve postlingual insufficiency and apnea events were eventually resolved. Clinical Trial Registration: None.