LAUSR

Address for Correspondence: Dr. Marcio Antonio Babinski, Morphology Department Biomedical Institute Fluminense Federal University, Av. Prof. Hernani Mello 101, CEP 24.210-150, Niterói, RJ, Brasil. (55) 21 2629-2335 E-Mail: [email protected] Background: The palmaris longus muscle is a slender fusiform muscle. It is especially prone to vary in comparison to other muscles in the upper limb and it is considered to be a vestigial structure. It is the most variable muscle in the human body, although its reverted state is barely discussed. The palmaris longus inversion can cause compression on neurovascular bundles, specially the median nerve on the carpal tunnel and the ulnar nerve on the Guyon canal. Case report: The present report describes a case of reversed palmaris longus, whereas its origin was composed by fleshy tissue and its distal portion was composed by a tendinous component. Furthermore, the reversed palmaris longus muscle was in association with an incomplete superficial palmar arch. Conclusion: Surgeons, radiologists and anatomists must be aware of the variations of the palmaris longus muscle. Prior knowledge those variations are helpful in planning intricate surgeries to which the palmaris longus muscle is useful.