Immunological markers and DNA content in a case of giant lymph node hyperplasia (Castleman's disease)

Little is known about the immunologic characteristics of the cells in giant lymph node hyperplasia (GLNH). For this reason, cell surface markers and intracytoplasmic immunoglobulins were determined on a case of GLNH. In addition, cellular DNA content was determined by flow analysis. A 59-year-old male underwent thoracotomy for a posterior madiastinal mass, which was entirely excised. Histologically, the mass was diagnosed as GLNH with features of both the hyaline-vascular and plasma-cell types. Preoperatively, the patient had a broad-based hypergammaglobulinemia with an increase in serum IgG. Two months postoperatively, the serum protein electrophoresis had returned to normal. Surface immunoglobulins (SIg) were determined on fresh cells in suspension using a polyvalent antiserum and monospecific antisera against heavy and light chains. Ten percent of the cells had SIg. The distribution of SIg-bearing cells was polyclonal. Intracytoplasmic immunoglobulin (CIg), as determined by immunofluorescence on ethanol-fixed smears from the cell suspensions, showed 6% positive cells. The distribution of cytoplasmic immunoglobulin was similarly polyclonal. Ethanol-fixed frozen sections also showed a polyclonal pattern when stained for CIg. Fifty-two percent of fresh cells in suspension formed Erosettes. These immunologic characteristics do not differ from those observed in non-neoplastic lymphoid tissues. A DNA content histogram was obtained by flow microfluorometry using ethanol-fixed cells stained with propidium iodide following RNase treatment. The DNA content distribution was within the normal limits established by the study of non-neoplastic lymphoid tissues.