Giant lymph node hyperplasia (Castleman's disease) of hyaline vascular type. Clinical heterogeneity with immunohistologic uniformity.

Of three patients with giant lymph node hyperplasia (GLNH) of hyaline vascular type, one had multicentric involvement and systemic symptoms, and had the nephrotic syndrome develop. The two others had localized adenopathy and were asymptomatic. Immunohistochemistry carried out on frozen and paraffin-embedded tissue was uniform in all cases. For the most part this revealed a polyclonal B-cell population and a reactive T-cell population in keeping with reactive follicular hyperplasia. In contrast to the latter, however, was a total absence of Leu-7 (natural killer cell) activity. The significance of this is unclear but may represent an abnormal immunologic response in the face of overwhelming antigenic stimulation. GLNH is a clinically and pathologically heterogeneous disorder, the management of which is dependent on both the clinical presentation of the patient and the histologic appearances of the involved lymph nodes.