RESUMO
Variations of the forearm musculature are vastly described in the literature. The palmaris longus muscle is one of the most variable structures of the human body. It usually arises from the medial epicondyle of the humerus and inserts itself into the palmar aponeurosis. Anatomy textbooks and recent papers state that this muscle may act as a weak wrist flexor. The present work aims to report an anatomical variation where the palmaris longus muscle was abnormally hypertrophied and was completely fleshy throughout the whole forearm. Anatomical variations of the palmaris longus may induce symptoms of neurovascular bundle compression, especially of the median nerve. The palmaris longus muscle may be used in tendon graft or muscle graft, due to its lack of apparent function. Furthermore, it is one of the anatomical landmarks for local anaesthesia procedures. (Folia Morphol 2018; 77, 2: 403-405).