Bone pearl: An enigmatic supernumerary ossicle of the thumb

Abstract

A 73-year-old Polynesian male exhibits a small, round, supernumerary bone along the radial diaphysis of the proximal phalanx of the right thumb. This accessory bone resembles a pearl in shape and color and is firmly attached via soft tissue, a ligament. A search of the literature failed to reveal any supernumerary bones attached to the radial surface of the first proximal phalanx. The presence of this supernumerary bone, although quite small and different from other small ossicles in the human skeleton, is potentially important to clinicians, anatomists, and anthropologists. This bone, or others like it, could be symptomatic and represents a rare trait that contributes to our knowledge of anatomical variation in hand bones.