Intradural Extramedullary Small Cell Lung Cancer Metastasis Resection: 2-Dimensional Operative Video.

Abstract

The presented surgical video (Video 1) demonstrates the resection of an intradural extramedullary metastasis in a 62-year-old female patient with a history of metastatic small cell lung cancer (SCLC). SCLC commonly metastasizes to the central nervous system.¹^,² However, the vast majority of such metastases are to the brain.¹^,² Interestingly, the presented patient had a cerebellar SCLC metastasis operated on 10 months earlier. Several cases of intradural extramedullary spinal drop metastases arising from cerebellar tumors have been described in the literature, suggesting that a drop metastasis is a likely mechanism to explain this rare topography.^3-5 Preoperatively, the patient presented with 1 month of back pain and rapidly progressing left lower extremity weakness and myelopathic signs so surgery was offered.^6-10 Interval imaging showed an intradural extramedullary T4-T5 lesion suspicious for metastatic disease. The patient consented to the procedure. Intraoperatively, fluoroscopy was used to identify the T4-T6 pedicles, and laminectomies were performed. A T4-T6 durotomy was then performed under ultrasound guidance to ensure adequate tumor exposure. Careful dissection was carried out around the cranial and caudal poles of the lesion. Subsequently, central debulking was performed and the tumor was resected in piecemeal fashion. Complete resection required sacrifice of the left T5 nerve root and cutting of the dentate ligament in 2 locations for adequate visualization. Postoperative neurologic exam demonstrated improvement in her lower extremity weakness, and postoperative magnetic resonance imaging showed gross total resection. The postoperative course was uneventful, and the patient was discharged home on postoperative day 6.