Monoclonal evolution of angioimmunoblastic lymphadenopathy.

A patient with angioimmunoblastic lymphadenopathy diagnosed on initial lymph node biopsy was found on rebiopsy two months later to have immunoblastic lymphoma as well. At presentation she had polyclonal hypergammaglobulinemia with polyclonal (kappa and lambda light chains) immunoblasts demonstrated by the immunoperoxidase stain. During the course of her illness, a monoclonal IgM kappa gammaglobulinemia developed, accompanied by monoclonal (kappa light chains only) immunoblasts demonstrated by the immunoperoxidase method. These findings were unique in that lymphomatous transformation and clinical deterioration are shown to be accompanied by a monoclonal evolution of immunoblasts. This constitutes further evidence for the heterogeneous nature of patients who have angioimmunoblastic lymphadenopathy and the malignant potential of this disease.