Clinical features of spinal schwannomas in 65 patients with schwannomatosis compared with 831 with solitary schwannomas and 102 with neurofibromatosis Type 2: a retrospective study at a single institution

Abstract

<jats:sec> <jats:title>OBJECT</jats:title> <jats:p>The aim of this study was to evaluate the clinical features of spinal schwannomas in patients with schwannomatosis and compare them with a large cohort of patients with solitary schwannomas and neurofibromatosis Type 2 (NF2).</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>The study was a retrospective review of 831 patients with solitary schwannomas, 65 with schwannomatosis, and 102 with NF2. The clinical, radiographic, and pathological data were extracted with specific attention to the age at onset, location of tumors, initial symptoms, family history, and treatment outcome.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>The male-to-female ratio of patients with schwannomatosis (72.3% vs 27.7%) was significantly higher than that of patients with solitary schwannomas (53.3% vs 46.7%) and NF2 (54.0% vs 46.0%), respectively (chi-square test, p = 0.012). The mean age at the first spinal schwannoma operation of patients with NF2 (24.7 ± 10.2 years) was significantly younger than that of patients with solitary schwannomas (44.8 ± 13.2 years) and schwannomatosis (44.4 ± 14.1 years; 1-way ANOVA, p &lt; 0.001). The initial symptoms were similar among the 3 groups, with pain being the most common. The distribution of spinal tumors among the 3 groups was significantly different. The peak locations of spinal schwannomas in patients with solitary schwannomas were at C1–3 and T12–L3; in schwannomatosis, the peak location was at T12-L5. A preferred spinal location was not evident for intradural-extramedullary tumors in NF2. Only a slight prominence in the lumbar area could be observed. The patients in the 3 groups obtained similar benefits from the operation; the recovery rates in the patients with solitary schwannomas, NF2, and schwannomatosis were 50.1%, 38.0%, and 53.9%, respectively. The prognosis varied among spinal schwannomas in the patients with schwannomatosis. Up until the last date of follow-up, most patients with schwannomatosis (81.5%) had undergone a single spinal operation, but 12 patients (18.5%) had undergone multiple spinal operations. Patients with nonsegmental schwannomatosis or those with early onset disease seemed to have a poor prognosis; they were more likely to undergo multiple spinal operations. Small cauda equina nodules were common in patients with schwannomatosis (46.7%) and NF2 (86.9%); these small schwannomas appeared to have relatively static behavior. Two patients suspicious for schwannomatosis were diagnosed with NF2 with the detection of constitutional NF2 mutations; 1 had unilateral vestibular schwannoma, and the other had suspicious bilateral trigeminal schwannomas.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>The clinical features of spinal schwannomas vary among patients with solitary schwannomas, NF2, and schwannomatosis. Spinal schwannomas of patients with NF2 appear to be more aggressive than those in patients with solitary schwannomas and schwannomatosis. Spinal schwannomas of schwannomatosis predominate in the lumbar area, and most of them can be treated successfully with surgery. The prognosis varies among spinal schwannomas of schwannomatosis; some patients may need multiple operations due to newly developed schwannomas. Sometimes, it is difficult to differentiate schwannomatosis from NF2 based on clinical manifestations. It is prudent to perform close follow-up examinations in patients with undetermined schwannomatosis and their offspring.</jats:p></jats:sec>

Sporadic NF2 Mosaic: Multiple spinal schwannomas presenting with severe, intractable pain following pregnancy

“…Although two punctate cauda equina lesions were not resected it is unlikely they represented ‘drop metastases’ since en bloc curative resection of two larger, ‘parent’ compressive spinal lesions revealed schwannoma and a third smaller ependymal spinal lesion lacked histologic features of myxopapillary ependymoma. Small cauda equina nodules occurred commonly in schwannomatosis and in neurofibromatosis type 2 (NF2), but did not undergo significant enlargement during 1.5 years mean follow-up [5] consistent with minimal enlargement in the cauda equina lesions and the absence of new intraspinal mass lesions (six months after surgery) in our patient. Taken together, this suggests the distal thecal sac lesions are even less likely to represent myxopapillary ependymoma whose management would require adjunctive radiotherapy.…”

“…Enlargement of a presumed intradural-extra-medullary schwannoma in the left ventral thecal sac at L1 level suggests the need for periodic, MRI imaging (every 6–12 months) to assess for progression of external compression of the conus medullaris prior to the onset of a return in symptoms. In the report by Li et al [5] twelve of sixty-five patients with multiple spinal schwannomas required multiple spinal operations. Younger age at first spinal operation (34.8 vs. 46.5 years old) was significantly associated with the need for multiple spinal operations and the median interval of repeat spinal operation was six years [5].…”

“…In the report by Li et al [5] twelve of sixty-five patients with multiple spinal schwannomas required multiple spinal operations. Younger age at first spinal operation (34.8 vs. 46.5 years old) was significantly associated with the need for multiple spinal operations and the median interval of repeat spinal operation was six years [5]. …”

Multiparametric whole‐body anatomic, functional, and metabolic imaging characteristics of peripheral lesions in patients with schwannomatosis

“…Although there have been prior reports on the clinical features of SWN, the imaging features of this disorder have been only sparsely reported, limited to descriptions of whole‐body tumor burden by anatomic imaging, and two case reports on FDG‐PET avidity . We have expanded the description of radiological attributes of SWN using multiparametric and multimodality whole‐body imaging based on MRI signal characteristics and enhancement patterns, assessment of functional characteristics with DWI/ADC, and metabolic imaging features with PET.…”

Creation of an international registry to support discovery in schwannomatosis

“…Individuals with schwannomatosis are known to medical centers around the world, but most centers provide care for only a small number of patients. This reality has contributed to the natural history of schwannomatosis being poorly understood and based on small case series from individual centers [Huang et al, ; Gonzalvo et al, Merker et al, ; Li et al, ]. Additional complexity comes from the genetic and phenotypic variability of schwannomatosis.…”