Lateral Neck Fistula (Branchial Anomaly) vs. Sternomastoid Tumor
Left picture: The diagnosis is a second branchial anomaly, namely a lateral neck fistula of the right side. The prominence of the sternocleidomastoid muscle is caused by the posture. Right picture: The diagnosis is a tumor of the sternocleidomastoid muscle; this pathology may be combined with a torticollis, or lead to a congenital muscular torticollis, and is caused by an intrauterine compartment syndrome.
In both young infants the right or the left sternocleidomastoid muscle, respectively, seems to be prominent. Right picture: The peak of the black triangle points to the medially situated prominent left sternocleidomastoid muscle; it has a circumscript prominence which is rough on palpation and tapers off gradually in the muscle in a cranial and caudal direction. Left picture: Here, the right sternocleidomastoid muscle is as prominent as the left one in the case of the contralateral picture. This prominence, however, is caused by the posture needed for the examination; the main finding is a barely recognizable opening of a fistula at this site.