Brachial plexus neuroma mimicking local recurrence of malignant mesenchymal tumor after forequarter amputation.

A stump neuroma is an attempt for the repair of a nerve following amputation. This article presents a case of a 60-year-old woman who was suspected of having a local recurrence on the chest wall following amputation of the left arm for a malignant mesenchymal tumor. The tumor did not show any invasion to adjacent structures thereby any necessity for chest wall resection and reconstruction. The patient underwent local excision of the tumor with reamputation of the branches of the lower brachial plexus, subclavian artery, and proximal one third of the clavicle. The tumor was eventually diagnosed as a brachial plexus neuroma. Although rare, cases that require left pneumonectomy with a transthoracic forequarter amputation including brachial plexus resection have been reported. Transection of the brachial plexus also may be needed during resection of a superior sulcus tumor. These cases often undergo an aggressive chest wall resection that includes the subclavian artery and vein in addition to the brachial plexus, particularly in tumors involving the lower truncus. Therefore, when recurrent chest wall tumor is suspected in such cases, stump neuroma resulting from transection of the brachial plexus should be included in the differential diagnosis.