Background: Thoracic outlet syndrome is an uncommon cause of upper extremity neuropathy resulting from either neurogenic or vascular compromise in the thoracic outlet. Congenital anomalies as the cause of this disease process represent a minority of cases, and the literature regarding their surgical management is still evolving.
Case report: A 42-year-old female without any relevant history presented to a clinic for evaluation of worsening neuropathic symptoms in the upper left extremity. Initial physical exam was unremarkable, and MRI identified an anomalous first rib, but no abnormality of the brachial plexus. The patient was managed conservatively for almost 4 years before symptoms became debilitating. Physical exam at that time found atrophy and weakness in the muscles supplied by the upper trunk of the brachial plexus, and CT demonstrated anomalies of the bone and brachial plexus not apparent on previous MRI. Neurolysis with local resection of the abnormal bone led to successful resolution of the patient's symptoms.
Conclusion: Identification of a rare congenital anomaly allowed for a precise surgical treatment of the condition. The importance of careful selection of modality and review of imaging in diagnosis and operative planning is discussed.