En bloc resection for extra-nodal Rosai-Dorfman disease in the anterior mediastinum: a case report.

Rosai-Dorfman disease (RDD) is a sinus histiocytosis with an undefined etiology and usually presents with painless massive lymphadenopathy. RDD is a benign histiocytic proliferative disease with extremely low incidence and commonly in young patients. Isolated intrathoracic RDD is comparatively rare in clinical practice with non-specific clinical manifestations, and can only be diagnosed after histological confirmation. Here, we reported a 28-year-old female who complained of a one-year cough with unknown causes, and chest contrast-enhanced computed tomography showed a soft-tissue density and slightly strengthened mass with 6.8 cm * 2.4 cm detected in the anterior-upper mediastinum. We suggested that en bloc resection of mediastinal RDD with potential adjacent tissue invasion was dependable and could lead to a favored prognosis. This case emphasizes the importance of considering RDD in the differential diagnosis of anterior mediastinal masses.