A rapidly expanding lesion in the neck: unusual presentation of Castleman's disease.

We report a painless but rapidly enlarging 9 cm x 4 cm lobulated hard neck mass. CT scanning suggested lymphoid tissue that was not confirmed by cytopathology. Histopathological analysis of the excision specimen detected Castleman's disease, extending to the resection margin. Postoperative radiotherapy was administered. The patient remains disease-free after 44 months.