Surgical Management of Giant Thoracic Paraspinal Schwannomas

Giant paraspinal thoracic schwannomas (GPTSs) are benign, slow-growing, encapsulated lesions. They can be intracanalicular, span more than 2 vertebral bodies, and/or have a foraminal component with extraspinal extension >2.5 cm. They pose surgical challenges because of the often unfamiliar complex regional anatomy. We report the largest series of GPTSs and discuss regional surgical strategies for tumors in the thoracic spine.

We conducted a retrospective review of GPTSs operated at a national spinal referral center between December 2008 and October 2019. Inclusion criteria included World Health Organization grade 1 GPTS. Patient demographics, clinical features, radiology, and histopathology were assessed.

Seventeen patients (12 females, 5 males) had a mean age of 48.1 years (range 21-65 years). Five GPTS (29%) were located at T1-T3, 6 (35%) at T4-6, and 6 (35%) below T6. The mean maximum diameter was 58.5 ± 19.1 mm (range 30-91 mm). Mean volume was 90.9 cm³ (range 19.1-350.6 cm³). Twelve (70%) had a fluorodeoxyglucose positron emission tomography scan showing low (25%) or moderate to high (75%) uptake. Six patients (35%) had preoperative computed tomography-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); 5) posterior/posterolateral (2/17); and 6) 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).

A 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 tumor extension but often requires anterior or combined approaches.