Conus and Cauda Equina Tumors

Conus and cauda equina lesions can produce overlapping sacral symptoms, but the pattern matters. Cauda equina lesions typically cause asymmetric radicular pain and sensory loss with lower motor neuron findings; bladder and bowel dysfunction tends to occur with severe disease or later in the course. Conus lesions more often produce earlier sphincter dysfunction and may combine lower motor neuron findings with corticospinal tract signs. ScienceDirectScienceDirectCauda equina - an overview

Treat acute or progressive lower-extremity weakness, saddle or perineal sensory disturbance, new urinary retention or incontinence, bowel dysfunction, or rapidly escalating radicular pain as possible neural compression. Important alternatives include large disc herniation, metastatic epidural disease, infection, hematoma, trauma, and intradural tumor. Wolters Kluwer+2Wolters KluwerSpine : Operative NeurosurgeryScienceDirectTime to Surgery and Outcomes in Cauda Equina Syndrome: An Analysis of 45 CasesScienceDirectCauda equina - an overview

Obtain MRI of the relevant spinal region with and without gadolinium for a suspected conus or cauda equina tumor. MRI defines lesion compartment, cord or root compression, enhancement pattern, cystic or hemorrhagic components, and associated syrinx or leptomeningeal disease. CT helps characterize osseous destruction, calcification, or surgical bony anatomy; CT myelography is an acceptable alternative when MRI cannot be performed. Wolters KluwerWolters KluwerSpine : Operative Neurosurgery

Image the full neuraxis when intramedullary tumor, myxopapillary ependymoma, or disseminated disease is a concern, because leptomeningeal spread can occur with selected spinal tumors. The supplied literature supports this principle for spinal ependymoma variants and myxopapillary ependymoma but does not provide a formal surveillance protocol. ccjm+1ccjmEpendymoma of the spinal cord and cauda equina: a reviewpubs rsnaA Radiologist’s Guide to the 2021 WHO Central Nervous System Tumor Classification: Part 2—Newly Described and Revised Tumor Types

Myxopapillary ependymoma is centered most often in the conus-cauda equina region and is now classified as CNS WHO grade 2 because of recurrence risk comparable with conventional spinal ependymoma; leptomeningeal dissemination can occur despite an overall favorable prognosis. pubs rsnapubs rsnaA Radiologist’s Guide to the 2021 WHO Central Nervous System Tumor Classification: Part 2—Newly Described and Revised Tumor Types Older literature supports complete surgical excision when feasible, with local recurrence being the dominant failure pattern; the historical evidence base is heterogeneous and predates current molecular classification. ccjmccjmEpendymoma of the spinal cord and cauda equina: a review

Cauda equina neuroendocrine tumors, formerly called cauda equina paragangliomas, are typically well-circumscribed intradural-extramedullary masses of the cauda equina or filum terminale. MRI may mimic schwannoma or ependymoma; reported supportive features include serpentine flow voids or a dilated vessel related to hypervascularity. ScienceDirect+1ScienceDirectCauda equina neuroendocrine tumors: an 11-year retrospective report on clinicopathological characteristics and postoperative recurrencepubs rsnaA Radiologist’s Guide to the 2021 WHO Central Nervous System Tumor Classification: Part 2—Newly Described and Revised Tumor Types In a 10-patient retrospective series, all tumors underwent gross-total resection and no recurrence was reported, but long-term and external validity remain uncertain. ScienceDirectScienceDirectCauda equina neuroendocrine tumors: an 11-year retrospective report on clinicopathological characteristics and postoperative recurrence

Intradural lumbar disc herniation is a rare but actionable mimic of intradural tumor. Consider it when imaging suggests a large central disc lesion, especially if the expected epidural disc fragment is not found after level confirmation at surgery. MRI signs such as the hawk-beak, Y, and crumble disc signs are suggestive rather than diagnostic; gadolinium-enhanced MRI can help distinguish disc material from solid or cystic lesions. cellcellIntradural lumbar disc herniation: A case report and literature review

Surgery is generally indicated for progressive neurologic deficits, clinically significant conus or cauda equina compression, spinal instability, substantial mechanical pain from structural compromise, or the need for tissue diagnosis when it will change oncologic management. For intradural-extramedullary tumors, observation can be reasonable in asymptomatic patients, but progressive neurologic symptoms favor surgery. Wolters KluwerWolters KluwerSpine : Operative Neurosurgery

For intramedullary tumors, the objective is maximal safe resection. Ependymomas and hemangioblastomas may have clearer surgical planes than astrocytomas; astrocytomas are often internally debulked when a safe cleavage plane is absent. The supplied review supports use of motor and somatosensory evoked-potential monitoring during resection. Wolters KluwerWolters KluwerSpine : Operative Neurosurgery

For metastatic epidural compression, treatment selection includes neurologic status, spinal stability, location and extent of compression, tumor responsiveness to radiation, prior radiation, and expected survival. A randomized trial cited in the supplied review found decompressive surgery followed by radiation superior to radiation alone for maintained ambulation in selected patients. Wolters KluwerWolters KluwerSpine : Operative Neurosurgery

Postoperative follow-up should document motor, sensory, gait, bladder, bowel, and sexual function, because residual deficits can persist even after decompression. In cauda equina syndrome, urinary or sexual dysfunction may persist after treatment. Wolters KluwerWolters KluwerSpine : Operative Neurosurgery

After gross-total resection of a circumscribed cauda equina lesion, surveillance imaging is directed by the pathologic diagnosis and extent of resection. Ependymomas can recur late, and myxopapillary ependymoma may disseminate leptomeningeally; therefore, a durable surveillance plan should be established with the operating neurosurgeon and neuro-oncology team. ccjm+1ccjmEpendymoma of the spinal cord and cauda equina: a reviewpubs rsnaA Radiologist’s Guide to the 2021 WHO Central Nervous System Tumor Classification: Part 2—Newly Described and Revised Tumor Types

For spinal metastases, the follow-up strategy should integrate neurologic status, pain, stability, systemic disease control, and response to local radiation or surgery. Wolters KluwerWolters KluwerSpine : Operative Neurosurgery