Absence of the Right Musculocutaneous Nerve: a rare cadaveric report

Aims: The MusculoCutaneous Nerve (MCN) is a branch that originates from the lateral cord and descends along the lateral side of the distal part of the axillary artery. Since the MCN is the only nerve for the innervation of the anterior compartment muscles of the arm, any variation in this nerve may be clinically important. Case presentation: During a routine dissection of the upper limb of a 48-year-old male cadaver in the Department of Anatomical Sciences at Tarbiat Modares University, Iran, a unilateral absence of the MCN was observed. Conclusion: In compensation, the anterior compartment muscles of the arm receive a supplementary branch from the Median Nerve (MN). Clinically, if this surrogate nerve’s origin is injured, it could lead to palsy in the coracobrachialis, biceps brachii, and brachialis muscles. Consequently, the individual may experience difficulty flexing the arm and lose skin sensation. Therefore, the absence of the MCN is vital information to consider during arm surgeries.