A Cadaveric Case of Palmaris Longus Agenesis and Reversal.

The palmaris longus frequently exhibits anatomical variations with palmaris longus agenesis and reversal being the most prevalent. These variations are relevant clinically, as the muscle is often used during plastic surgeries for grafting tendons. They are also relevant in pathology, as hypertrophy of the reversed muscle is related to median nerve compression. In this report, we describe an unusual case in which a male cadaver-donor exhibited a right-sided palmaris longus reversal and left-sided palmaris longus agenesis. Review of the literature documents no previous co-occurrence of these anomalies. Since the muscle has relevance in a variety of contexts within medicine and surgery, reporting on a variation like this carries significant educational and clinical value.