A case of Castleman's lymphoma of the neck and its immunohistological study.

Castleman's lymphoma was diagnosed of the neck in a 21-year-old female.The patient complained of a gradually enlarging tumor on the left side of her neck. The preoperative diagnosis was lymphoid hyperplasia. The tumor was removed and identified histologically as a hyaline-vascular type of Castleman's lymphoma.Immunohistological studies were performed to clarify the nature of the tumor. All elements of a lymphnode were present follicles, germinal centers, and intrafollicular spaces, plasma cells produced both κ and λ immunoglobulin. There was little evidence of inflammation and most of the lymphocytes were B cells. The tumor was therefore classified as a lymphoid hamartoma.