Sinus histocytosis with massive lymphadenopathy (Rosai-Dorfman disease) in a patient with primary Sjogren's syndrome.

Sinus histocytosis with massive lymphadenopathy is a rare disease that has been described by Rosai and Dorfman. It is characterized by massive, cervical lymphadenopathy, with extranodal manifestations in about 40% of patients. It occurs as a distinct entity, never associated with other diseases, and in most cases the prognosis is good. Lymphadenopathy is also a frequent sign of patients with primary Sjogren's syndrome (SS), usually associated with disease activity or concurrent infection. However, excessive lymphadenopathy in SS patients is a sign of lymphoproliferative disorder development. In this report, we describe a patient with primary SS, and excessive lymphadenopathy and splenomegaly who developed Rosai-Dorfman disease, and we discuss the possible aetiopathophysiological mechanism linking these two entities.