Castleman's disease is an uncommon benign lymphoid disorder usually found in the mediastinum (70 %) which is thought to be due to antigenic hyperstimulation of unknown origin. Two histological subtypes may be found in relation to two different clinical patterns with clinical and therapeutic implications. Diagnosis is frequently accomplished only by histological analysis after surgery since no specific features have been found in imaging studies. Surgical excision is both diagnostic and curative in localized forms, whereas additional therapies are required in multicentric forms. This report is of Castleman's disease presenting as a neck mass, an infrequent occurrence, with an analysis of management controversies and a review of the literature.