Focal changes of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) associated with nodular lymphocyte predominant Hodgkin's disease.

Sinus histiocytosis with massive lymphadenopathy (SHML/Rosai-Dorfman disease) has, on rare occasions been identified as an isolated phenomenon in lymph nodes affected by malignant lymphomas. The Registry includes four cases of SHML in patients with non-Hodgkin's lymphomas and one with multiple myeloma. SHML has more recently been recorded as a focal finding in lymph nodes involved by Hodgkin's disease of the mixed cellularity type. We report two patients presenting with lymphadenopathy caused by involvement by nodular lymphocyte predominant Hodgkin's disease with focal changes of SHML, an association not previously recorded in the literature. Responsiveness of the histiocytic cells of SHML to B-cell derived cytokines is postulated as a mechanism for this phenomenon, an hypothesis previously raised in regard to the association of focal Langerhans cell histiocytosis with Hodgkin's disease and with non-Hodgkin's lymphomas.