Harlequin syndrome in a young patient with osteosarcoma after pleural metastasectomy: A case report and a mini review of the literature.

Harlequin syndrome is a rare autonomic disorder with at least 83 reported cases in literature, 6% of which are congenital. When the fibers responsible for sudomotor and vasomotor supply to the face at the T2-T3 level are unilaterally blocked, it leads to hemifacial discoloration. This results in one-half of the face appearing flushed and hyperemic, sharply contrasting with the pale appearance of the other half. The cause of this syndrome is unknown; however, it appears to involve an autonomic nervous system dysfunction. It can be caused by an injury, compression, or blockade of sympathetic fibers along the pathway. The present study was a case of a metastatic osteosarcoma patient with a history of video-assisted thoracic surgery pleurectomy that presented in Attikon University Hospital (Athens, Greece) with worsening dyspnea and right-sided facial flushing.