Immunohistological characterization of lymph nodes in two cases of adult onset Still's disease.

Although lymphadenopathy occurs in 60% of patients with adult Still's disease, its histopathological pattern has only recently been described. We report on the immunohistological study of a lymph node biopsy and the clinical course of 2 patients with adult Still's disease. The lymph node histology was characterized by a diffuse paracortical expansion with a high content of immunoblasts and plump endothelium venules. Immunohistochemistry using the alkaline phosphatase, antialkaline phosphatase technique showed the mixed B and T cell nature both of proliferating cells and immunoblasts. When antiheavy and light chain reagents were applied, the B cell component became polytypic. Our report stresses the relevance of immunohistological investigation in the diagnostic approach to Still's disease in which histological findings, if taken alone, might be misleading.