A Variant Extensor Pollicis Brevis Crossing the Anatomical Snuff Box

Abstract

During an educational dissection, accessory tendon of the extensor pollicis brevis muscle was found on the left side in a Korean cadaver. The abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus muscles showed normal morphology and course: however, narrow muscle belly originated between the extensor pollicis brevis and extensor pollicis longus muscles. It crossed the anatomical snuff box and then inserted on the base of the distal phalanx of the thumb. The author describes this previously novel case report and discusses the clinical implications of such a variant.