Intercostobrachial nerve

The intercostobrachial nerve, also known as the lateral cutaneous branch of the second intercostal nerve, is a peripheral sensory nerve. It originates from the second thoracic spinal nerve (T2) and sometimes receives contributions from T3. The nerve pierces through chest wall muscles including serratus anterior, crosses into the axilla, and supplies sensation to skin overlying parts of the axilla and medial/posterior upper arm. It does not have motor function or branches. Clinically, it is significant because it may be injured during surgical procedures involving the axilla—most notably breast cancer surgeries requiring lymph node removal—leading to numbness or altered sensation in its distribution area. The intercostobrachial nerve can also be intentionally blocked with local anesthetic for certain surgical procedures on the upper limb or chest wall. This structure is not considered a therapeutic molecular target, such as an enzyme or receptor relevant to drug development; rather, it is an anatomical structure important in regional anesthesia and surgical planning.

Other names

Lateral cutaneous branch of the second intercostal nerveNervus intercostobrachialis (Latin)ICBN (occasionally used in clinical literature)

Nerve blockade by local anesthetics inhibits sensory transmission from its cutaneous territory