Atypical presentation of extranodal Rosai-Dorfman disease.

We describe a 42-year-old woman with progressive dyspnea on exertion resulting from pulmonary artery compression by a mediastinal mass due to extranodal Rosai-Dorfman disease. After initial biopsies were inconclusive, she underwent surgical resection of the mass to relieve the pulmonary artery compression, which was causing severe right ventricular dysfunction. Debulking of the mass required resection and reconstruction of the ascending aorta, pulmonary trunk, and bilateral pulmonary arteries using cardiopulmonary bypass and circulatory arrest. We believe this is the first report of Rosai-Dorfman disease manifesting as compression of the thoracic great vessels.