Abstract

Harlequin syndrome is characterized as ipsilateral loss of vasomotor and sudomotor function with contralateral hyperhidrosis and flushing in response to heat, exercise, or emotional stimuli caused by disruption to the sympathetic cervical chain. Here, we present a case of Harlequin syndrome in a 1-year-old male with subsequent identification of paraspinal neuroblastoma. Though Horner syndrome, another form of dysautonomia, has been associated with neuroblastoma, this is the first documentation of Harlequin syndrome with neuroblastoma in the English medical literature. Familiarity with the underlying anatomy and pathophysiology should be understood to prevent misdiagnosis in patients with potential early signs of neuroblastoma.