Unicentric, multifocal Castleman disease of the mediastinum associated with cerebellitis.

A 30-year-old man presented with rapidly progressive cerebellar symptoms. Brain magnetic resonance imaging was consistent with cerebellitis. A subsequent chest computed tomography revealed a multilobulated anterior mediastinal mass, which was diagnosed on the surgical biopsy specimen as hyaline vascular Castleman disease. After resection of the mediastinal mass and multiple involved adjacent mediastinal lymph nodes, the cerebellitis resolved. To the best of our knowledge, this is the first report of Castleman disease associated with cerebellitis. This rare case of suspected paraneoplastic cerebellitis related to a multifocal unicentric Castleman disease confined to the mediastinum is discussed.