Extranodal Rosai-Dorfman disease presenting as a cardiac mass in an adult: report of a unique case and lack of relationship to IgG4-related sclerosing lesions.

Rosai-Dorfman disease (also known as sinus histiocytosis with massive lymphadenopathy) is a rare disease of unknown etiology that typically presents as nodal disease in young children. However, it also can present in various extranodal sites and can be difficult to recognize if not considered in the differential diagnosis. We describe a 55-year-old man who was discovered to have extranodal Rosai-Dorfman disease that presented as a cardiac mass involving the left atrium and ventricle during evaluation for atypical chest pain, and discuss the clinical, radiologic, and pathologic findings as well as treatment approach and consideration of a possible relationship of this entity to IgG4-related sclerosing lesions.