Horner Syndrome in a Pediatric Patient: A Case Report of Lymphatic Malformation Induced Presentation in a 7-year-old Boy

Lymphatic malformations are low-flow vascular anomalies that predominantly affect the cervicofacial region in the pediatric population. We describe a case of a 7-year-old healthy boy who presented to the emergency department with the classic triad of miosis, ptosis, and anhidrosis. Initial evaluation, including a cervicocranial computed tomography scan, revealed no intracranial space-occupying lesion. Subsequent diagnostic work-up, involving ultrasound and cervicothoracic magnetic resonance imaging, identified a cystic lesion in the upper mediastinum, consistent with the diagnosis of lymphatic malformations. The integration of a multidisciplinary team proved essential in reaching a definitive diagnosis and selecting the optimal treatment (ultrasound-guided sclerotherapy) mitigating the risk of life-threatening and cosmetic complications.