Erdheim-Chester Disease with atrial mass and perinephric calcification.

Erdheim-Chester Disease is a multi-systemic condition characterized by non-Langerhans histiocytic infiltration. Cardiovascular involvement with pseudotumoral infiltration of the right atrium is present in approximately one-third of patients and may be asymptomatic. Although retroperitoneal fibrosis is common, perinephric dystrophic calcification has not been previously described.