Rosai-Dorfman Disease: Report of a Case Associated with IgG4-Related Sclerotic Lesions.

We describe a rare case of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) associated with a six-year history of autoimmune pancreatitis, which was controlled by steroid treatment. The patient presented with multiple, cervical and thoracic lymphadenopathy and abnormal, nodular opacities in the lung. Histologically, Rosai-Dorfman disease with numerous IgG4-positive cells was identified in a subcutaneous lymph node in the patient's left forearm. The patient recovered uneventfully with steroid treatment.