Van Tonder, Daniel JohannesLorke, D.E.Nyirenda, T.Keough, Natalie2022-07-192022-07-192022-09Van Tonder D.J., Lorke D.E., Nyirenda T. & Keough N. 2022, 'An uncommon, unilateral motor variation of the intercostobrachial nerve', Morphologie, vol. 106, no. 354, pp. 209-213, doi : 10.1016/j.morpho.2021.06.003.1286-011510.1016/j.morpho.2021.06.003https://repository.up.ac.za/handle/2263/86289The intercostobrachial nerve (ICBN) is commonly defined as a purely sensory nerve supplying the skin of the lateral chest wall, axilla, and medial arm. However, numerous branching patterns and distributions, including motor, have been reported. This report describes an uncommon variant of the right ICBN observed in both an 86-year-old white female cadaver and a 77-year-old white male cadaver. In both cases the ICBN presented with an additional muscular branch, termed the “medial pectoral branch”, piercing and therefore innervating the pectoralis major and minor muscles. Clinically, the ICBN is relevant during surgical access to the axilla and can result in sensory deficits (persistent pain/loss of sensory function) to this region following injury. However, damage to the variation observed in these cadavers may result in additional partial motor loss to pectoralis major and minor.en© 2021 Published by Elsevier Masson SAS. Notice : this is the author’s version of a work that was accepted for publication in Morphologie. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Morphologie, vol. 106, no. 354, pp. 209-213, 2022. doi : 10.1016/j.morpho.2021.06.003.Intercostobrachial nerve (ICBN)Lateral cutaneous branchSecond intercostal nerveMedial pectoral branchMastectomyPectoralis minorPostprint Article