An unusual union of the intercostobrachial nerve and the medial pectoral nerve.

Variations in the branching pattern of the intercostobrachial nerve have been known to complicate dissection during mastectomy and other procedures involving the axilla. We present the case of an 87-year-old Caucasian female, in whom the intercostobrachial nerve joined with a separate branch from the medial pectoral nerve. The clinical consequences of such a variation may include pectoral muscle motor loss, in addition to the commonly reported sensory loss resulting from the accidental injury or intentional sacrifice of the intercostobrachial nerve during axillary dissection.