{'fraction_non_alphanumeric': 0.02443280977312391, 'fraction_numerical': 0.015125072716695753, 'mean_word_length': 5.035087719298246, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 2, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Giant invasive spinal schwannoma: its clinical features and surgical management.

BACKGROUND
Giant invasive spinal schwannoma (GISS) is defined as a lesion that extends over > 2 vertebral levels, erodes vertebral bodies, and extends posteriorly and laterally into the myofascial planes. Because of its rarity, few reports have been issued.


OBJECTIVE
To analyze the clinical features and outcomes of GISS and to discuss surgical strategies.


METHODS
We analyzed the medical records, pathological findings, and radiographic studies of patients with GISS.


RESULTS
Fourteen patients with GISS were surgically treated between 2002 and 2007. Five lesions were in the sacral region, 4 in the lumbosacral, 2 in the thoracolumbar, and 1 each in the cervical, cervicothoracic, and thoracic regions. Gross total resection was performed in 11 of the 14 patients. Satisfactory decompression was performed in all patients for neural compression. Postoperatively, all patients showed relief of preoperative pain and paresthesia. The growth potential with the Ki-67 index was > 2% in 6 patients, and 4 of them experienced tumor regrowth or recurrence. All patients were followed up for at least 24 months. Final follow-up magnetic resonance images showed asymptomatic small tumor recurrence on the sacrum in 2 patients. Two patients required spinal stabilization. No instability was found on follow-up.


CONCLUSION
Total resection is the treatment of choice for patients with GISS and provides functional improvements, low permanent morbidity, and a low rate of recurrence. Total resection of the intraspinal portion and regular follow-up with consideration of the Ki-67 index is recommended when total resection is not achieved.