IT IS not uncommon in pediatric practice to see examples of asymmetry involving parts of the face or even, at times, of the extremities. However, when this asymmetry affects a complete side and is found in the bone structure as well as in the soft tissues it is rare enough to report. The number of such cases described in the literature to date is still probably under the one hundred mark. These cases, described as instances of total (or complete) asymmetry, may be of the atrophic or hypertrophic type. The nature and especially the causation of this condition have never been satisfactorily explained, and this is so in no small measure because of the lack of autopsied material. In an article published in 1942, Schwartzman and others1 stated that only 4 cases have come to postmortem examination. In the case we are about to report we were able to