Second Branchial Cyst vs. Chronic Lymphadenitis
Left picture: The diagnosis is a lateral cyst of the neck (second branchial cyst). Right picture: In this case the diagnosis is a chronic lymphadenitis in atypical mycobacteria, cat scratch disease, or toxoplasmosis, or other causes. In this case report the age and the history of the child may be useful for the differential diagnosis. Left picture: This patient is one year old, therefore, a congenital malformation seems likely. The age speaks against a sterocleidomastoid tumor (the patient is not a newborn); so does the local finding (no firm mass, which is not continuously tappering off in the muscle). A cystic lymphangioma would be another possibility, in which case the mass would be rather smooth, not as tight as in a lateral cyst of the neck (except for an acute increase, for instance due to a hemorrhage in the lymphangioma). Right picture: In this case a schoolchild is involved, therefore, a lymphadenopathy, together with the other findings, receives priority.
In both patients a mass of the superior half of the lateral neck is present. The proximity to the jaw angle and to the sternocleidomastoid muscle is obvious. Left picture: Here, the mass lies in front and over the sternocleidomastoid muscle, is cystic on palpation, and the overlying skin is non-irritant. Right picture: Here, the local finding lies far from the sternocleidomastoid muscle in direction of the lower jaw, is rough, and the overlying skin is insignificantly reddish.