Immunoblastic malignant lymphoma in adult onset Still's disease.

Lymphadenopathy commonly occurs in patients with adult onset Still's disease (AOSD). Besides the more common reactive hyperplasia, the histological pattern may occasionally be confused with that of malignant lymphoma. A case of AOSD that developed an immunoblastic malignant lymphoma is described. Immunohistochemistry showed the B cell nature of the proliferating cells. As a result, AOSD should be added to the list of systemic rheumatic diseases, the course of which may be complicated by lymphoproliferative malignancies. Our case underlines the need for a careful examination and of close followup to detect this eventuality earlier.