Poster 23: Electrodiagnostic Testing Leading to a Diagnosis of Pancoast’s Tumor: A Case Report

Abstract

Setting: Electrodiagnostic medicine clinic. Patient: A 55-year-old man. Case Description: The patient is right-handed dominant male painter with a 20-pack-year smoking history and a history of back injury 1 year ago. 6 months ago, he developed sudden pain in the left shoulder, numbness in the left forearm, and sharp hand burning pain. The patient also presented with atrophy of the medial left hand intrinsic muscles. He denied any neck pain. He was referred to the electrodiagnostic clinic to assess for cervical radiculopathy. Assessment/Results: Electromyography and nerve conduction study showed electrodiagnostic evidence of severe axonotmetic left lower-trunk plexopathy with sensory axonal peripheral neuropathy. In light of the patient’s electrodiagnostic findings and history of smoking, a chest computed tomography (CT) was recommended to rule out carcinomatous process. CT of the chest revealed a mass in the left superior sulcus of the lung, which was suspicious for Pancoast’s tumor. The patient then underwent surgical resection of the left upper lobe with excision and biopsy of the mass. On biopsy, the lung mass was compressing the lower trunk of the brachial plexus. The biopsy report showed evidence of poorly differentiated stage 2 adenocarcinoma with extension into visceral pleura, with no regional lymph node involvement. Discussion: Pancoast’s tumors are much less common than other lung cancers. These tumors comprise 1% to 3% of all lung cancers. After resection of the tumor, the patient had increased strength and sensation in the left hand as well as decreased shoulder pain. Conclusions: It is important to rule out Pancoast’s tumor in patients with lower-trunk plexopathies. A diagnosis of carcinomatous neuropathy should be strongly considered in a patient with sensory axonal neuropathy. The symptoms produced by the disorder can be mimicked by numerous neurologic or musculoskeletal disorders, thus delaying diagnosis. A careful neurologic exam, radiographs, and electromyography and nerve conduction studies guide and verify the diagnosis.