Background and Importance: Klippel-Trénaunay syndrome is a rare congenital condition that rarely affects peripheral nerves. Median nerve involvement at the carpal tunnel level has only been reported on four occasions of this syndrome in the medical literature.
Case Presentation: A 61-year-old Caucasian female patient with Klippel-Trénaunay syndrome presented with a 10-month history of paraesthesia and numbness affecting the median nerve distribution area of her left hand. The clinical and neurophysiological examination confirmed a moderately severe carpal tunnel syndrome that required surgical decompression.
Conclusion: Pre-operative findings demonstrated diffuse vascular infiltration and engorgement of the median nerve. Flexor tendons had a normal appearance. The patient had a satisfactory post-operative period with full resolution of her symptoms 4 weeks after the procedure. Although peripheral nerves are rarely affected in patients with Klippel-Trénaunay syndrome, neurological symptoms could indicate nerve involvement and magnetic resonance imaging (MRI) examination should be considered to further assess the extension of the lesion.