A Case Series of Surgically Treated Spinal Dumbbell Tumors of Critical Parent Nerve Roots: To Cut or Not to Cut?

A separate-dural-incision method of extradural dumbbell spinal schwannoma resection: cumulative experience at a single center

OBJECTIVE

To present our experience in the surgical management of completely extradural dumbbell spinal schwannomas with a new surgical strategy.

METHOD

This study is a case series of patients treated at the Neurosurgery Department of the First Affiliated Hospital of USTC, between January 2018 and June 2021.

RESULTS

24 patients met the inclusion criteria, with cervical and lumbar spines being the most frequent locations. All patients underwent surgical treatment. Total gross resection was accomplished in all patients. Two cases had numbness and no case exhibited motor deficit. There was no postoperative CSF leakage or wound infection.

CONCLUSION

Based on a limited number of observations, we conclude that our technique was feasible and effective for the treatment of extradural dumbbell spinal schwannomas.

CLINICAL TRIAL

http://www.chictr.org.cn/ , No. ChiCTR2400086171.

Sacrifice of Involved Nerve Root during Surgical Resection of Foraminal and/or Dumbbell Spinal Neurinomas

Even if usually needed to achieve the gross total resection (GTR) of spinal benign nerve sheath tumors (NSTs), nerve root sacrifice remains controversial regarding the risk of neurological deficit. For foraminal NSTs, we hypothesize that the involved root is poorly functional and thus can be safely sacrificed. All spinal benign NSTs with foraminal extension that underwent surgery from 2013 to 2021 were reviewed. The impacts of preoperative clinical status and patient and tumor characteristics on long-term outcomes were analyzed. Twenty-six patients were included, with a mean follow-up (FU) of 22.4 months. Functional motor roots (C5-T1, L3-S1) were involved in 14 cases. The involved nerve root was routinely sacrificed during surgery and GTR was obtained in 84.6% of cases. In the functional root subgroup, for patients with a pre-existing deficit (n = 5/14), neurological aggravation persisted in one case at last FU (n = 1/5), whereas for those with no preop deficit (n = 9/14), a postoperative deficit persisted in one patient only (n = 1/9). Preoperative radicular pain was the only characteristic significantly associated with an immediate postoperative motor deficit (p = 0.03). The sacrifice of an involved nerve root in foraminal NSTs seems to represent a reasonable and relevant option to resect these tumors, permitting one to achieve tumor resection in an oncologic fashion with a high rate of GTR.

Pure lumbar foraminal cavernous malformation in a patient with Cowden syndrome-a case report

BACKGROUND

Spinal cavernous malformations (CMs) are slow flow venous vascular malformations which can occur in vertebral body, epidural space or intramedullary. Only 7 cases were described confined in foraminal space. Cowden syndrome (CS) is an autosomal dominant genodermatosis that may present and develop vascular malformations, which include CM. They were found intracranial, and rarely visceral. No association with spinal CM and CS has been reported to date.

CASE DESCRIPTION

A 46-year-old patient with CS came to our attention with a L5 radiculopathy secondary to a slow-growing intra-foraminal mass lesion, with bony scalloping. The lesion mimicked a schwannoma at radiological imaging and intraoperative findings. En bloc resection with root sacrifice was performed. No excessive bleeding was observed. After surgical resection, anatomical pathology demonstrated a CM. Postoperative review of neuroimaging revealed features compatible with chronic resolved peripheral haemorrage. The patient had no intra- or post-operative complications, and an immediate relief of symptoms was observed. The follow-up spinal magnetic resonance imaging (MRI) obtained 3 months after surgery, demonstrated the total removal of the lesion.

CONCLUSIONS

CMs can be confined to foraminal space and associated with CS. They may mimic peripheral nerve sheath tumors. Diagnosis may be challenging. No pathognomonic imaging features were found. Complete resection with root sacrifice seems to be a safe and efficient technique.

A significant association between C5 nerve sheath tumors and new postoperative weakness

OBJECTIVE

The objective of this study was to determine if patients with nerve sheath tumors affecting the C5 spinal nerve are at greater risk for postoperative weakness than those with similar tumors affecting other spinal nerves contributing to the brachial plexus.

METHODS

A retrospective chart review (1998-2020)identified patients with pathologically confirmed schwannomas or neurofibromas from the C5 to T1 nerves. Patients with plexiform nerve sheath tumors, tumors involving more than 1 nerve, and malignant peripheral nerve sheath tumors were excluded. Collected variables included basic demographics, tumor dimensions, its location relative to the dura, involved nerve level, surgical approach, extent of resection, presenting symptoms, postoperative neurological deficits, and recurrence rate.

RESULTS

Forty-six patients (23 men, 23 women) were identified for inclusion in the study with an average age of 47 ± 17 years, BMI of 28 ± 5 kg/m2, and follow-up of 32 ± 45 months. Thirty-nine patients (85%) had schwannomas and 7 (15%) had neurofibromas. Tumors involved the C5 (n = 12), C6 (n = 11), C7 (n = 14), C8 (n = 6), and T1 (n = 3) nerves. Multivariable logistic regression analysis with an area under the curve of 0.85 demonstrated C5 tumor level as an independent predictor of new postoperative weakness (odds ratio 7.4, p = 0.028). Of those patients with new postoperative weakness, 75% improved and 50% experienced complete resolution of their motor deficits.

CONCLUSIONS

Patients with C5 nerve sheath tumor resections are at higher odds of new postoperative weakness. This may be due to the predominant single innervation of shoulder muscle targets in contrast to other upper extremity muscles that receive input from 2 or more spinal nerves. These findings are important for clinical decision-making and preoperative patient counseling.