Bilateral Origin of Intercostobrachial Nerve from First Intercostal Nerve: Clinical Implications

The intercostobrachial nerve (ICBN) is the undivided lateral cutaneous branch of the second intercostal nerve that communicates with the medial cutaneous nerve of the arm. Iatrogenic intercostobrachial nerve injury may present in the postoperative period as paresthesia and dysesthesia. The probable utilization of the ICBN as a sensory nerve donor has also been proposed. We present a case of aberrant bilateral ICBN emerging from the first intercostal nerves in a 69-year-old male cadaver. The extra thoracic portions of ICBN on both sides were found emerging from the first intercostal spaces. On the right side, it communicated with the medial cutaneous nerve of the arm; on the left side, it communicated with both medial cutaneous nerves of the arm and forearm. Awareness about variant ICBN is clinically important during surgical exploration in the axilla.