Castleman's disease as a uncommon cause of a neck mass.

Castleman's disease is an uncommon cause of a neck mass; in only 6% of the cases reported in the literature was the disease located in the neck. We present the case of a 21-year-old woman who developed a swelling in the left side of her neck that was subsequently diagnosed as Castleman's disease. The different forms of the disease and its histopathology are discussed.