Surgical Management of Giant Thoracic Paraspinal Schwannomas.

Abstract

INTRODUCTION\nGiant paraspinal thoracic schwannomas (GPTS) are benign, slow growing, encapsulated lesions. They can be intracanalicular, span more than two vertebral bodies and/or have a foraminal component with extraspinal extension greater than 2.5cm. They pose surgical challenges because of the often-unfamiliar complex regional anatomy. We report the largest series of GPTS and discuss regional surgical strategies for tumours in the thoracic spine.\n\n\nMETHODS\nRetrospective review of GPTS operated at a national spinal referral centre, between December 2008 and October 2019. Inclusion criteria included WHO grade 1 GPTS. Patient demographics, clinical features, radiology and histopathology were assessed.\n\n\nRESULTS\n17 patients (12 females, 5 male). Mean age 48.1 years (range 21-65 years). 5 GPTS (29%) were located at T1-T3, 6 (35%) at T4-6 and 6 (35%) below T6. Mean maximum diameter was 58.5±19.1mm (range 30-91mm); mean volume 90.9cm3 (range 19.1-350.6cm3). Twelve (70%) had an FDG PET scan showing low (25%) or moderate-high (75%) uptake. Six patients (35%) had preoperative CT guided biopsy. Surgical approaches included: 1. Manubriotomy and variations (4/17); 2. High lateral thoracotomy (4/17); 3. Posterior parascapular (1/17); 4. Standard lateral thoracotomy (3/16); 4. Posterior/posterolateral (2/17); combined posterior and thoracotomy (3/17). All patients had gross total resection and were grade 1 cellular schwannomas. No recurrence at final follow-up (mean 36.1 months, range 8-130 months).\n\n\nCONCLUSION\nA number of approaches are available to resect GPST in specific locations in the thoracic spine. Total resection is achievable despite complex regional anatomy, location and tumour extension, but often requires anterior or combined approaches.