English: Posterior triangle of the neck labeled. (Anterior triangles to the left. Occipital triangle labeled at center left.) ). Cystic hygromas are classically found in the posterior triangle of the neck (purple).
Unless stated otherwise, this image is from the 20th U.S. edition of Gray's Anatomy of the Human Body, originally published in 1918 and therefore lapsed into the public domain. A copy of Gray's Anatomy can be found on Bartleby and also on Yahoo!.