Predictive factors of postoperative deficit and functional outcome after surgery for upper limb schwannomas: Retrospective study of 21 patients

Surgery of Schwannoma in the upper limb - sensitivity and specificity of preoperative magnetic resonance imaging and relation between tumour size and symptoms

BACKGROUND

Benign peripheral nerve tumours consist of different types, most commonly Schwannomas. Preoperative Magnetic Resonance Imaging (MRI) is commonly performed before surgery and Pathoanatomical Diagnosis (PAD) confirms the diagnosis. Our aims were to study the utility of MRI and the relation between tumour size and symptoms.

METHODS

Retrospectively, patients, surgically treated for benign nerve tumours between 2008 and 2019, were identified and preoperative MRI, with measurement of tumour size, PAD, symptoms, peroperative details, and symptomatic outcomes of surgery, were analysed.

RESULTS

The sensitivity and specificity to correctly identify Schwannomas with preoperative MRI were 85% and 50%, respectively, based on 30 Schwannomas and nine neurofibromas that were identified. Tumour size did not affect the presence of preoperative symptoms, but patients with sensory dysfunction at last follow-up had larger Schwannomas (p < 0.05). Symptoms as a palpable tumour, paraesthesia and pain improved by surgical excision (p < 0.001, p < 0.001 and p < 0.012, respectively), but sensory and motor dysfunction were common postoperatively. No malignant peripheral nerve sheath tumours (MPNST) were found. Using a surgical microscope, instead of only loop magnification, lowered the risk of perioperative nerve injuries (p < 0.05), but did not further diminish postoperative symptoms.

CONCLUSIONS

Early and accurate diagnosis of Schwannomas is valuable for adequate presurgical preparation and prompt surgical intervention. Preoperative examination with MRI has a high sensitivity, but low specificity; although recent advancement in MRI technology indicates improvement in diagnostic precision. Surgical excision is preferably performed early in conjunction with symptomatic debut to improve outcome.

Benign nerve tumours in the upper limb: a registry-based study of symptoms and surgical outcome

Surgery for benign nerve tumours is performed for pathoanatomical diagnosis and symptomatic relief, but might cause residual problems. We aimed to assess patient-reported symptoms and disability before and after surgery at a national level. In total, 206 cases surgically treated for a benign peripheral nerve tumour 2010-2019 registered in the Swedish Quality Registry for Hand Surgery (HAKIR; response rates 22-34%) were analysed. Surgery reduced overall disability in the affected limb (QuickDASH 18/100 [IQR 5-36] preoperatively and 5/100 [IQR 0-22] 12 months postoperatively), improved ability to perform daily activities (HQ-8; 11/100 [IQR 0-50] preoperatively and 0/100 [IQR 0-20] 12 months postoperatively) and decreased three evaluated pain modalities: pain at rest (HQ-8; 20/100 [IQR 0-40] preoperatively and 0/100 [IQR 0-10] 12 months postoperatively), pain on motion without load (HQ-8; 20/100 [IQR 0-40] preoperatively and 0/100 [IQR 0-10] 12 months postoperatively), and pain on load (HQ-8; 24/100 [IQR 1-69] preoperatively and 1/100 [IQR 0-30] 12 months postoperatively). Cold sensitivity was a minor problem both before and after surgery (HQ-8; 0/100 [IQR 0-30] preoperatively and 1/100 [IQR 0-40] 12 months postoperatively). We conclude that surgery for benign peripheral nerve tumours provides good symptomatic relief with low risk for residual problems.