The rare five finger pectoralis nerves: A case report

Abstract

The brachial plexus is a complex network of nerve tissue in the human body that has been reported to vary from person to person. We describe a very rare variation of the brachial plexus found on a routine cadaveric dissection. On the left side of the chest, we identified two lateral pectoral nerves arising from the lateral cord and innervating the pectoralis major muscle; two medial pectoral nerves (MPNs) arising from the medial cord that innervates both pectoral muscles and a communicating branch that connects the lateral and MPN. In addition, this communicating branch had a nerve that innervated the pectoralis minor muscle. Knowing the variations of branching of the pectoral nerves is critical when performing any medical procedure in the pectoral region, such as plastic breast reconstruction surgery after modified radical mastectomy in breast cancer, removal of the pectoral muscles, anesthetizing the brachial plexus, or axillary dissection.