17%, in one study
In a 1999 study of lymphangiomas in 186 children
, 17% of patients had a recurrence after macroscopic complete (surgeon removed all tumor that he could see) surgical removal.
Complete removal was in 145 children. Recurrence rates were higher (40% recurrence rate) with laser
removal or with incomplete surgical removal. See the abstract of the study here: http://www.Ncbi.Nlm.Nih.Gov/pubmed/10442614.
Answer assisted by Steve Krager, Medical Student