Percutaneous Peripheral Nerve Stimulation for Treatment of Brachial Plexopathy Secondary to Pancoast Tumor: A Case Report

Abstract

Background: Pancoast tumors can result in significant arm and shoulder pain due to invasion of the lower brachial plexus (BP). They are usually treated by chemoradiotherapy followed by surgical resection, which may alleviate the pain. When patients respond poorly to chemoradiation and the tumor is not surgically resectable, options to treat the pain are limited. We report here successful use of percutaneous peripheral nerve stimulation (PNS) with leads inserted under ultrasound (US)-guidance for treatment of brachial plexopathy in a patient with an unresectable Pancoast tumor unresponsive to chemoradiation. Case Report: The patient was a 70-year-old woman with an unresectable poorly differentiated squamous cell carcinoma of the left lung status post chemoradiation with poor response and recently started on immune therapy who presented to her oncologist with refractory left upper extremity (LUE) pain and weakness. She was admitted for pain control, and pain management was consulted. Physical examination findings were concerning for involvement of the lower trunk of the BP, findings confirmed in imaging. Patient elected to proceed with placement of a PNS. Device was successfully placed under US guidance. Patient responded well for the first 2 weeks with significant improvement in allodynia and hyperesthesia, however, at week 3, physical examination was significantly changed and further growth of the tumor was seen on imaging. The PNS was removed at this time. Conclusion: This case demonstrates successful use of PNS to treat refractory neuropathic pain in a patient with a locally advanced Pancoast tumor. US imaging made it possible to identify the interscalene BP and accurately place the leads. The PNS achieved its desired outcome of providing pain relief in the lower trunk distribution for the full 3 weeks it was in place. Pain from Pancoast tumors can be severe, and neural blockade via PNS to interrupt pain is an option for patients with intractable pain. Additional prospective study is warranted to determine the efficacy of this technique. Key words: Brachial plexus, upper extremity, cancer pain, interventional pain management, neuromodulation, peripheral nerve stimulation