Hepatic rosai-dorfman disease with coincidental lymphoma: report of a case.

Rosai-Dorfman disease (RDD; sinus histiocytosis with massive lymphoadenopathy) is a rare, usually nodal self-limited disease. Sometimes nodal disease is coupled with extranodal localizations, in which case the disease can follow a protracted clinical course characterized by remissions and relapses and, exceptionally, a fatal outcome. Exclusive extranodal localizations are rare and their prognosis variable. This study reports a case of RDD apparently limited to the liver coexisting with a diffuse (stage IV) relapsing follicular lymphoma. The patient is alive and well 24 months after the diagnosis of the lymphoma. It is conceivable that the lymphoma has induced RDD via an immunological disorder, possibly involving interleukin expression. The favorable outcome supports the belief that the prognosis of RDD is largely dependent on the number of extranodal sites involved, rather than on the specific sites themselves.