From Diagnosis to Resolution: A Case Study of Myxopapillary Ependymoma Survival.

Myxopapillary ependymoma (MPE) is a rare, slow-growing tumor that commonly arises in the lumbosacral region of the spinal cord, within the filum terminale and cauda equina. The frequent presentation of MPE is back, sacral, or leg pain. The tumor's size, site, and extension usually influence these symptoms. MPE is usually evaluated using magnetic resonance imaging (MRI) because of its superior soft tissue contrast. The best treatment modality is total surgical resection, which improves the long-term survival rate, with follow-up imaging recommended to ensure total resolution. Here, we present the case of a 29-year-old male who presented with symptoms suggestive of severe neurological impairment. An MRI scan revealed an intradural lesion arising from the cauda equina with peripheral and intrathecal haemorrhage, consistent with MPE. He was managed with laminectomy and microsurgical resection of the tumor, which achieved total resection. Postoperative follow-up found gradual improvement in his symptoms, and routine surveillance imaging confirmed the complete resolution of the tumor.

Giant metastatic mixed-type spinal ependymoma presenting with hydrocephalus.

Ependymomas are rare nervous system tumors that can arise anywhere in the neuraxis. While having a high propensity for leptomeningeal dissemination, retrograde dissemination (from the spine to the CNS) remains infrequent. We describe the case of a 31-year-old female who presented with hydrocephalus secondary to an intracranial leptomeningeal metastasis of a giant spinal ependymoma with mixed (classic and myxopapillary) histopathologic features, successfully treated with surgical resection and radiotherapy of the entire neuraxis. This case highlights the importance of including ependymomas in the differential diagnosis for lesions in atypical extra-axial locations, of systematically obtaining imaging of the entire neuraxis when suspecting it, and of considering retrograde dissemination when both intracranial and spinal lesions are present.

Treatment of Extraneural Metastases of Myxopapillary Ependymomas With Dose-Dense Temozolomide and Lapatinib.

Myxopapillary ependymomas (MPEs) are rare tumors of the central nervous system, and outcomes are generally worse with recurrent disease. These tumors can rarely metastasize outside the neuraxis. We present a case of a 35-year-old female with a history of MPEs who developed extraneural metastases 11 years after her initial gross total resection. Sites of metastases included multiple bilateral intrapulmonary and pleural-based masses with pleural effusion and a pelvic mass. The patient was treated with dose-dense TMZ and lapatinib and had a mixed radiographic response after 12 cycles of treatment. This is the first known case of extraneural metastases of MPEs to demonstrate a radiographic response to dose-dense TMZ and lapatinib. This case presentation discusses the need to establish optimal treatment of extraneural ependymal metastases, duration of treatment, and strategy for the management of recurrent diseases.

Myxopapillary Ependymoma Metastasis Mimicking Pulmonary Embolism: An Illustrative Case.

Myxopapillary ependymomas (MPEs) are rare spinal cord tumors with low rates of metastasis outside of the neuraxis. Gross total resection of MPEs can significantly improve progression-free survival; however, adjunctive treatment remains unstandardized. A 29-year-old female with a history of spina bifida occulta surgical correction and lower back pain presented with dyspnea and tachycardia. A large pulmonary artery mass was discovered consistent with pulmonary thromboembolism. It was subsequently determined to be an intravascular metastasis secondary to sacral MPE. Standardization of MPE treatment and clinical suspicion of spinal neoplasm in the setting of chronic back pain with undetermined origin are of value.

Cauda equina myxopapillary ependymoma in von Hippel-Lindau disease: A case report.

Background: Patients affected by Von Hippel-Lindau (VHL) are prone to develop central nervous system neoplasms such as hemangioblastomas (HBs). Myxopapillary ependymoma (MPE) is not commonly associated with VHL disease. Case Description: We present the first case of a VHL patient affected by simultaneous silent cauda equina MPE and a symptomatic conus medullaris HB. The patient was first operated for systemic tumors and followed for asymptomatic HBs. Simple surveillance was maintained until neurological symptoms appeared. Regular follow-up demonstrated objective growth of the cystic conus medullaris tumor while the cauda equina lesion remained stable. Surgery was performed to avoid further neurological worsening. Histopathological examination showed conus medullaris HB and a nearby cauda equina MPE. Conclusion: Simultaneous spinal HBs and isolated MPE may exceptionally occur in VHL patients.

Outcomes and Pattern of Care for Spinal Myxopapillary Ependymoma in the Modern Era-A Population-Based Observational Study.

(1) Background: Myxopapillary ependymoma (MPE) is a rare tumor of the spine, typically slow-growing and low-grade. Optimal management strategies remain unclear due to limited evidence given the low incidence of the disease. (2) Methods: We analyzed data from 1197 patients with spinal MPE from the Surveillance, Epidemiology, and End Results (SEER) database (2000-2020). Patient demographics, treatment modalities, and survival outcomes were examined using statistical analyses. (3) Results: Most patients were White (89.9%) with a median age at diagnosis of 42 years. Surgical resection was performed in 95% of cases. The estimated 10-year overall survival was 91.4%. Younger age (hazard ratio (HR) = 1.09, p < 0.001) and receipt of surgery (HR = 0.43, p = 0.007) were associated with improved survival. Surprisingly, male sex was associated with worse survival (HR = 1.86, p = 0.008) and a younger age at diagnosis compared to females. (4) Conclusions: This study, the largest of its kind, underscores the importance of surgical resection in managing spinal MPE. The unexpected association between male sex and worse survival warrants further investigation into potential sex-specific pathophysiological factors influencing prognosis. Despite limitations, our findings contribute valuable insights for guiding clinical management strategies for spinal MPE.

Utility of Multimodal Intraoperative Neuromonitoring for Excision of Filum Terminale Ependymoma in Close Proximity to Conus.

Myxopapillary ependymomas (MPEs) are well-circumscribed tumors arising mainly from the caudal neuraxis, i.e., conus medullaris (CM) and filum terminale (FT), commonly seen in adults with median age at presentation of 39 years.1 Owing to its partially aggressive clinical behavior involving cerebrospinal fluid dissemination and local recurrence, MPE is classified as grade 2 in the fifth edition of the World Health Organization Classification of Tumors of the Central Nervous System.2 Gross total resection without capsular violation is key, with subtotal resection being directly associated with local recurrence.3The FT has an intradural and extradural component. The intradural FT extends from the inferior tip of the CM to the coccyx.4 The intradural FT-CM junction is not demarcated, but rather a zone of transition, with neural tissue being incrementally replaced by fibrous tissue of filum, gradually converging to a pure non-neural FT.5 In intramedullary FT MPE in close proximity to the lower end of conus, achieving gross total resection presents a great challenge. Neuromonitoring is crucial to ensure preservation of vital CM functions. We present the case of a 33-year-old man with focal nocturnal back pain of 6 months' duration followed by bilateral lower limb deep boring pain. He had no neurological deficits. Preoperative magnetic resonance imaging revealed a T2 hyperintense, heterogeneous contrast-enhancing intradural extramedullary mass at L1. Video 1 highlights step-by-step en bloc excision of the FT MPE with technical nuances, including intraoperative neurophysiological monitoring. Triggered electromyography (EMG) was used to positively map the eloquent CM and identify the intradural FT-conus interface at the superior pole of the tumor, which was then carefully dissected under continuous bulbocavernosus reflex monitoring. Similarly, we confirmed non-neural intradural FT at the lower pole by negative mapping and resected the lesion en bloc with an adequate stump for clear margins. Free-run EMG monitored all the rootlets that adhered to or were in close proximity to the lesion, ensuring their integrity and an uneventful postoperative recovery. Figure 1 depicts the anatomical orientation of the lesion with surrounding neural structures. Histopathology confirmed MPE. En bloc resection with preservation of neurological function remains the mainstay of treatment for FT ependymoma. Understanding the transitional intradural FT-CM interface is essential, often precluding a clear filum stump superiorly while resecting MPE. Intraoperative neurophysiological monitoring is an indispensable adjunct to ensure safe en bloc resection. It is also theoretically possible to use tibial and pudendal sensory evoked potentials (SEPs) in this surgical procedure. However, the clinical utility of SEPs is limited in FT surgery compared with triggered EMG or transcranial motor evoked potentials because conventional SEPs from posterior tibial nerve of the lower extremity do not cover all the root levels at risk, and the change in SEPs cannot be immediately recognized (as SEPs are averaged responses, and there is always a time lag). We did not use pudendal SEPs in this study because SEPs may give information only on the sensory sacral pathway.6 Dermatomal SEPs may be helpful, but again, they provide only sensory information. Instead, we used triggered EMG for mapping the nerve roots and transcranial motor evoked potentials to monitor the motor tracts. Further, we used the bulbocavernosus reflex, an alternative and more precise technique to monitor both motor and sensory nervous pathways at the sacral root level. Moreover, SEPs are more difficult to monitor in very young children and are less relevant in guiding the surgical strategy. Thus, we used both mapping (triggered EMG) and monitoring (transcranial motor evoked potentials and bulbocavernosus reflex) techniques, which can preserve sensory and motor sacral roots in this surgical procedure.

A case of myxopapillary ependymoma with predominant giant cell morphology: A rare entity with comprehensive genomic profiling and review of literature.

In the evolving landscape of ependymoma classification, which integrates histological, molecular, and anatomical context, we detail a rare case divergent from the usual histopathological spectrum. We present the case of a 37-year-old man with symptomatic spinal cord compression at the L3-L4 level. Neuroradiological evaluation revealed an intradural, encapsulated mass. Histologically, the tumor displayed atypical features: bizarre pleomorphic giant cells, intranuclear inclusions, mitotic activity, and a profusion of eosinophilic cytoplasm with hyalinized vessels, deviating from the characteristic perivascular pseudorosettes or myxopapillary patterns. Immunohistochemical staining bolstered this divergence, marking the tumor cells positive for glial fibrillary acidic protein and epithelial membrane antigen with a characteristic ring-like pattern, and CD99 but negative for Olig-2. These markers, alongside methylation profiling, facilitated its classification as a myxopapillary ependymoma (MPE), despite the atypical histologic features. This profile underscores the necessity of a multifaceted diagnostic process, especially when histological presentation is uncommon, confirming the critical role of immunohistochemistry and molecular diagnostics in classifying morphologically ambiguous ependymomas and exemplifying the histological diversity within MPEs.

Implications of DNA Methylation Classification in Diagnosing Ependymoma.

BACKGROUND: Ependymoma is a central nervous system (CNS) tumor that arises from the ependymal cells of the brain's ventricles and spinal cord. The histopathology of ependymomas is indistinguishable regardless of the site of origin, and the prognosis varies. Recent studies have revealed that the development site and prognosis reflect the genetic background. In this study, we used genome-wide DNA methylation array analysis to investigate the epigenetic background of ependymomas from different locations treated at our hospital. METHODS: Four cases of posterior fossa ependymomas and 11 cases of spinal ependymomas were analyzed. RESULTS: DNA methylation profiling using the DKFZ methylation classifier showed that the methylation diagnoses of the 2 cases differed from the histopathological diagnoses, and 2 cases could not be classified. Tumor that spread from the brain to the spinal cord was molecularly distinguishable from other primary spinal tumors. CONCLUSIONS: Although adding DNA methylation classification to conventional diagnostic methods may be helpful, the diagnosis in some cases remains undetermined. This may affect decision-making regarding treatment strategies and follow-up. Further investigations are required to improve the diagnostic accuracy of these tumors.

Unusual location of myxopapillary ependymoma in the sacrum: Case report and review of the literature.

Myxopapillary ependymoma, a rare variant of ependymoma, commonly occurs in the conus medullaris or filum terminale. The rarity of these tumors can make their diagnosis and treatment challenging. This case report presents an atypical occurrence of myxopapillary ependymoma within the sacrum in a 68-year-old patient presented with a 3-month history of persistent left-sided low back pain radiating to the legs and fecal dysfunction. The patient underwent a sacral laminectomy and subtotal excision of the tumor, followed by adjuvant radiotherapy with favorable outcomes. This report highlights the significance of tailored approaches for unconventional tumor locations emphasizes the potential benefits of multimodal treatment strategies and provides insights from a comprehensive literature review on similar cases.

When a dermatopathologist encounters the ultra-rare: A case series of superficial soft tissue/cutaneous myxopapillary ependymomas.

Myxopapillary ependymoma (MPE) is an uncommon variant of ependymoma, almost exclusively seen in conus medullaris or filum terminale. MPE can be diagnostically challenging, especially when arising extra-axially. Here we report 5 cases of superficial soft tissue/cutaneous MPE, identified across three tertiary institutions. All patients were female and three of them (3/5, 60%) were children (median age 11 years, range 6-58 years). The tumors presented as slow-growing masses of the sacrococcygeal subcutaneous soft tissues, occasionally identified after minor trauma and clinically favored to be pilonidal sinuses. Imaging showed no neuraxis connection. Macroscopically, tumors were well-circumscribed, lobulated, and solid and microscopically they exhibited typical histopathology of MPE, at least focally. Two of the tumors (2/5, 40%) showed predominantly solid or trabecular architecture with greater cellular pleomorphism, scattered giant cells, and increased mitotic activity. All tumors (5/5, 100%) showed strong diffuse immunohistochemical expression of GFAP. One tumor clustered at the category "ependymoma, myxopapillary" by methylome analysis. Two patients (2/5, 40%) had local recurrence at 8 and 30 months after the initial surgery. No patients developed metastases during the follow-up period (median 60 months, range 6-116 months). Since a subset of extra-axial MPEs behaves more aggressively, timely and accurate diagnosis is of paramount importance.

Clinicoradiologic Characteristics of Intradural Extramedullary Conventional Spinal Ependymoma.

Purpose: Distinguishing intradural extramedullary (IDEM) spinal ependymoma from myxopapillary ependymoma is challenging due to the location of IDEM spinal ependymoma. This study aimed to investigate the utility of clinical and MR imaging features for differentiating between IDEM spinal and myxopapillary ependymomas. Materials and Methods: We compared tumor size, longitudinal/axial location, enhancement degree/pattern, tumor margin, signal intensity (SI) of the tumor on T2-weighted images and T1-weighted image (T1WI), increased cerebrospinal fluid (CSF) SI caudal to the tumor on T1WI, and CSF dissemination of pathologically confirmed 12 IDEM spinal and 10 myxopapillary ependymomas. Furthermore, classification and regression tree (CART) was performed to identify the clinical and MR features for differentiating between IDEM spinal and myxopapillary ependymomas. Results: Patients with IDEM spinal ependymomas were older than those with myxopapillary ependymomas (48 years vs. 29.5 years, p < 0.05). A high SI of the tumor on T1W1 was more frequently observed in IDEM spinal ependymomas than in myxopapillary ependymomas (p = 0.02). Conversely, myxopapillary ependymomas show CSF dissemination. Increased CSF SI caudal to the tumor on T1WI was observed more frequently in myxopapillary ependymomas than in IDEM spinal ependymomas (p < 0.05). Dissemination to the CSF space and increased CSF SI caudal to the tumor on T1WI were the most important variables in CART analysis. Conclusion: Clinical and radiological variables may help differentiate between IDEM spinal and myxopapillary ependymomas.

Resection of a large multisegmental filum terminale ependymoma through a multisegmental hemilaminectomy.

This video demonstrates a gross-total resection of a multisegmental intradural extramedullary tumor using only multisegmental hemilaminectomy. The patient is a 21-year-old woman presenting with only backache. MRI of the lumbar spine demonstrates a large multisegmental heterogeneously enhancing intradural extramedullary tumor extending down from the eleventh dorsal vertebrae down to the fifth lumbar vertebrae. The surgical video demonstrates the technique of multisegmental hemilaminectomy and microsurgical resection of the tumor without posterior spinal instrumentation. Postoperatively, the patient had no neurological deficit and was discharged on postoperative day 5. Three-month postoperative MRI shows no residual disease or spinal deformity.

Surgical outcomes and risk factors for recurrence of myxopapillary ependymoma: a single-center experience.

OBJECTIVE: Myxopapillary ependymomas (MPEs) are low-grade, well-circumscribed tumors that often involve the conus medullaris, cauda equina, or filum terminale. They account for up to 5% of all tumors of the spine and 13% of spinal ependymomas, with a peak incidence between 30 and 50 years of age. Because of the rarity of MPEs, their clinical course and optimal management strategy are not well defined, and long-term outcomes remain difficult to predict. The objective of this study was to review long-term clinical outcomes of spinal MPEs and identify factors that may predict tumor resectability and recurrence. METHODS: Pathologically confirmed cases of MPE at the authors' institution were identified and medical records were reviewed. Demographics, clinical presentation, imaging characteristics, surgical technique, follow-up, and outcome data were noted. Two groups of patients-those who underwent gross-total resection (GTR) and those who underwent subtotal resection (STR)-were compared using the Mann-Whitney U-test for continuous and ordinal variables and the Fisher exact test for categorical variables. Differences were considered statistically significant at p ≤ 0.05. RESULTS: Twenty-eight patients were identified, with a median age of 43 years at the index surgery. The median postoperative follow-up duration was 107 months (range 5-372 months). All patients presented with pain. Other common presenting symptoms were weakness (25.0%), sphincter disturbance (21.4%), and numbness (14.3%). GTR was achieved in 19 patients (68%) and STR in 9 (32%). Preoperative weakness and involvement of the sacral spinal canal were more common in the STR group. Tumors were larger and spanned more spinal levels in the STR group compared with the GTR cohort. Postoperative modified McCormick Scale grades were significantly higher in the STR cohort compared with the GTR group (p = 0.00175). Seven of the 9 STR patients (77.8%) underwent reoperation for recurrence at a median of 32 months from the index operation, while no patients required reoperation after GTR, for an overall reoperation rate of 25%. CONCLUSIONS: Findings of this study emphasize the importance of tumor size and location-particularly involvement of the sacral canal-in determining resectability. Reoperation for recurrence was necessary in 78% of patients with subtotally resected tumors; none of the patients who underwent GTR required reoperation. Most patients had stable neurological status postoperatively.

Classification and neuroimaging of ependymal tumors.

Ependymal tumors arise from the ependymal cell remnants of the cerebral ventricles, the central canal of the spinal cord, or the filum terminale or conus medullaris, although most pediatric supratentorial ependymomas do not exhibit clear communication or abutment of the ventricles. In this article, we discuss the classification, imaging characteristics, and clinical settings of these tumors. The WHO 2021 classification system has categorized ependymal tumors based on histopathologic and molecular features and location, in which they are grouped as supratentorial, posterior fossa (PF), and spinal. The supratentorial tumors are defined by either the ZFTA (formerly RELA) fusion or the YAP1 fusion. Posterior fossa tumors are divided into group A and group B based on methylation. On imaging, supratentorial and infratentorial ependymomas may arise from the ventricles and commonly contain calcifications and cystic components, with variable hemorrhage and heterogeneous enhancement. Spinal ependymomas are defined by MYCN amplification. These tumors are less commonly calcified and may present with the "cap sign," with T2 hypointensity due to hemosiderin deposition. Myxopapillary ependymoma and subependymoma remain tumor subtypes, with no change related to molecular classification as this does not provide additional clinical utility. Myxopapillary ependymomas are intradural and extramedullary tumors at the filum terminale and/or conus medullaris and may also present the cap sign. Subependymomas are homogeneous when small and may be heterogeneous and contain calcifications when larger. These tumors typically do not demonstrate enhancement. Clinical presentation and prognosis vary depending on tumor location and type. Knowledge of the updated WHO classification of the central nervous system in conjunction with imaging features is critical for accurate diagnosis and treatment.

Myxopapillary Ependymoma-a Case Report of Rare Multicentric Subtype and Literature Review.

Background: Myxopapillary ependymoma is a rare type of primary spinal tumor, it is distinctly a slow-growing tumor that originates in the conus medullaris, cauda equina, or film terminals and is rarely identified as a multicentric type. Myxopapillary ependymoma has a unique histological characteristic and is associated with a generally better prognosis. Objective: We present a case of a rare multicentric myxopapillary ependymoma. Case presentation: A 28-year-old male with 1-year history of low back pain and 3 months of radiating pain to left lower limb with perianal anesthesia. Magnetic resonance imaging (MRI) exhibited a large intradural intramedullary lesion from the level of the conus medullaris extending to the filum terminals at the level of T12 to L3 with smaller multiple enhancing lesions seen opposite to L4 and L5 level as well as within the exiting nerve roots, at the left side of L1/L2 and L2/L3 and right side of L3/L4 and L5/S1 level. The patient underwent surgical resection with significant improvement in symptoms and no tumor progression on follow up MRI scan. Conclusion: We hereby present a case of multicentric myxopapillary ependymoma with a literature review of the previous reported cases. We believe that our study will make a significant contribution to the literature and will be of interest to the readership regarding of the rarity of multicentric Myxopapillary ependymoma and it will help in decision making for the proper surgical Intervention on these kinds of cases.

Spinal Myxopapillary Ependymoma: A Rare Case and Review of Management Strategies.

Intramedullary myxopapillary ependymomas are rare spinal cord tumors primarily affecting young adults. Grade 2 tumors are associated with a higher proliferative index and potentially more aggressive behavior compared to grade 1 tumors. We present a case of a 30-year-old male who presented with a three-month history of progressive unilateral lower back pain that was refractory to analgesics. Neurological examination revealed bilateral lower limb weakness and sensory impairments in the L2 region. MRI confirmed a well-defined, enhancing intramedullary lesion at the L2 level, causing cord enlargement and edema. Diagnosis of grade 2 intramedullary myxopapillary ependymoma was made. Complete surgical resection was performed, confirming a grade 2 myxopapillary ependymoma. Postoperatively, the patient demonstrated significant improvement in lower limb function and sensation, with no tumor recurrence during long-term follow-up. Rehabilitation therapy was initiated, while close monitoring for complications and tumor progression was maintained. This case explores the etiology and features of intramedullary myxopapillary ependymomas and underscores the importance of early recognition, accurate diagnosis, and aggressive surgical management.

Myxopapillary Ependymoma of the Sacrum.

Teaching Point: Myxopapillary ependymoma presenting as a highly destructive lesion in the sacrum is rare but should be included in the differential diagnosis.

Clinical management and prognosis of spinal myxopapillary ependymoma: a single-institution cohort of 72 patients.

PURPOSE: Myxopapillary ependymoma (MPE) was classified as grade 2 tumor in the 2021 World Health Organization central nervous system classification because of its high recurrence probability. This study aimed to investigate predictive factors and management of tumor recurrence. METHODS: Seventy-two patients with spinal MPE underwent initial surgical treatment at our hospital between 2011 and 2021. Kaplan-Meier curves and Cox regression were used to analyze the correlation between clinical variables and progression-free survival (PFS). RESULTS: The median age at diagnosis was 33.5 years (range 8-60 years). Twenty-one patients (29.2%) had preoperative spinal drop metastases. Gross total resection (GTR) was performed in 37 patients (51.4%). The median follow-up was 7.2 years, and the follow-up rate was 88.9% (64 of 72 cases). Twelve of the 64 patients (18.9%) relapsed, and preoperative drop metastasis occurred in 7 patients (58.3%). The estimated 5-year and 10-year PFS rates were 82% and 77%, respectively. Univariate analysis showed that GTR was associated with improved PFS (hazard ratio [HR] 0.149, p = 0.014), while preoperative drop metastasis (HR 3.648, p = 0.027) and tumor involvement sacrococcygeal region (HR 7.563, p = 0.003) were associated with tumor recurrence. Adjuvant radiotherapy (RT) was significantly associated with improved PFS in patients with preoperative drop metastasis (p = 0.039). CONCLUSION: Complete surgical resection under the premise of protecting neurological function is an important factor in reducing spinal MPE recurrence. Adjuvant RT is recommended when the tumor invades the capsule with preoperative drop metastasis or adhesion to the nerve and cannot reach GTR.

Co-occurrence of subcutaneous myxopapillary ependymoma, dermal sinus tract, and filum terminale lipoma: a review of the pathobiology of caudal spinal cord development and spinal cord tethering. Illustrative case.

BACKGROUND: Myxopapillary ependymoma (MPE) is typically benign and found in the conus medullaris and/or filum terminale, although rare cases of subcutaneous and extra-axial MPE have been reported. The co-occurrence of MPE, tethered cord syndrome (TCS) with lipoma of the filum terminale, and a dermal sinus tract is extremely rare, with only 6 reported cases in the literature. Here, the authors present the first case, to their knowledge, of an extra-axial, subcutaneous MPE co-presenting with TCS, lipoma of the filum terminale, and a dermal sinus tract and discuss the underlying pathobiology. OBSERVATIONS: A 14-month-old male who presented for evaluation of a dermal sinus tract underwent magnetic resonance imaging, which revealed a tethered cord with associated lipoma. At 14 months, the patient underwent spinal cord detethering with resection of his sacral dimple and sinus tract. Histopathological evaluation revealed an incidentally found MPE within the dermal sinus tract. LESSONS: The authors review the underlying biology of MPEs, tethered cord syndrome, and dermal sinus tracts, and explore possible points of convergence within the developmental pathways that may result in this unique concomitant presentation. Additionally, they suggest that extra-axial MPE may be underappreciated and underdiagnosed; this case suggests that extra-axial MPE may be only effectively diagnosed with histological studies.