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Po Hsiang (Shawn) Yuan, Lukas Grassner, Charles Fisher, and Nicolas Dea


The diagnosis and management of acinic cell carcinoma (ACC) is often challenging given its similarity to benign tumors, high incidences of late recurrence and distant metastasis, and tendency to be resistant to systemic chemotherapy. A primary parotid ACC resulting in an intradural extramedullary mass has not been reported.


The authors describe such a case that presented as a progressive cervical myelopathy 29 years after initial diagnosis. The tumor, located at the C2–C3 level, infiltrated the dura and contained both extradural and intradural components. This occurred 18 months after the incomplete resection of an extradural metastasis at the same location.


Although intracranial and extradural metastases of various primary malignancies are well reported, secondary spinal intradural malignancies are rare. As a result, there are no established guidelines for the surgical management of intradural extramedullary metastases and prognosis may be difficult to establish. In this case, treatment options were limited because systemic therapy options had been exhausted and repeated radiation to the area was not recommended. We report on this case to highlight the clinical course of a rare local recurrence after spinal metastasis leading to an intradural extramedullary tumor and to show that surgical intervention can lead to improvement of neurological symptoms.

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Oliver G. S. Ayling, Y. Raja Rampersaud, Charlotte Dandurand, Po Hsiang (Shawn) Yuan, Tamir Ailon, Nicolas Dea, Greg McIntosh, Sean D. Christie, Edward Abraham, Christopher S. Bailey, Michael G. Johnson, Jacques Bouchard, Michael H. Weber, Jerome Paquet, Joel Finkelstein, Alexandra Stratton, Hamilton Hall, Neil Manson, Kenneth Thomas, and Charles G. Fisher


Treatment of degenerative lumbar diseases has been shown to be clinically effective with open transforaminal lumbar interbody fusion (O-TLIF) or minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Despite this, a substantial proportion of patients do not meet minimal clinically important differences (MCIDs) in patient-reported outcomes (PROs). The objectives of this study were to compare the proportions of patients who did not meet MCIDs after O-TLIF and MIS-TLIF and to determine potential clinical factors associated with failure to achieve MCID.


The authors performed a retrospective analysis of consecutive patients who underwent O-TLIF or MIS-TLIF for lumbar degenerative disorders and had been prospectively enrolled in the Canadian Spine Outcomes and Research Network. The authors analyzed the Oswestry Disability Index (ODI) scores, physical and mental component summary scores of SF-12, numeric rating scale (NRS) scores for leg and back pain, and EQ-5D scores of the patients in each group who did not meet the MCID of ODI at 2 years postoperatively.


In this study, 38.8% (137 of 353) of patients in the O-TLIF cohort and 41.8% (51 of 122) of patients in the MIS-TLIF cohort did not meet the MCID of ODI at 2 years postoperatively (p = 0.59). Demographic variables and baseline PROs were similar between groups. There were improvements across the PROs of both groups through 2 years, and there were no differences in any PROs between the O-TLIF and MIS-TLIF cohorts. Multivariable logistic regression analysis demonstrated that higher baseline leg pain score (p = 0.017) and a diagnosis of spondylolisthesis (p = 0.0053) or degenerative disc disease (p = 0.022) were associated with achieving the MCID at 2 years after O-TLIF, whereas higher baseline leg pain score was associated with reaching the MCID after MIS-TLIF (p = 0.038).


Similar proportions of patients failed to reach the MCID of ODI at 2 years after O-TLIF or MIS-TLIF. Higher baseline leg pain score was predictive of achieving the MCID in both cohorts, whereas a diagnosis of spondylolisthesis or degenerative disc disease was predictive of reaching the MCID after O-TLIF. These data provide novel insights for patient counseling and suggest that either MIS-TLIF or O-TLIF does not overcome specific patient factors to mitigate clinical success or failure in terms of the intermediate-term PROs associated with 1- to 2-level lumbar fusion surgical procedures for degenerative pathologies.