NASS 2025 RECAP
It May See You, Even If You Don’t See It— Workup of the Unknown Spinal Lesion and What Not to Miss
Azeem Ahmad, DO
Sinai Hospital of Baltimore Baltimore, MD
Akhil Chhatre, MD
Johns Hopkins Medicine Baltimore, MD
In the course of clinical practice, spine specialists will inevitably encounter lesions that defy immediate classification. Missed or misinterpreted spinal lesions can lead to misdiagnosis of reversible conditions, prompt unnecessary biopsies or surgical interventions, and potentially produce dangerous delays in care. Recognizing critical imaging characteristics – and knowing when to pause, re-image, biopsy, or refer – can meaningfully alter spine patient outcomes in any clinical setting.
Presented by the NASS Section on Spine Oncology at NASS 2025 in Denver, faculty from neurosurgery, orthopedic surgery, neuroradiology, and interventional radiology collaborated to lead a case-based discussion on elusive spinal lesions across a spectrum of etiologies. Rather than simply reviewing the imaging characteristics of a few distinct pathologies, the session instead emphasized how structured, evidence-based decision-making frameworks—alongside a careful history and physical examination—can empower providers to navigate unexpected imaging findings with greater confidence.
Metabolic Conditions and Spine Pathology Ajit Krishnaney, MD
Dr. Krishnaney (Cleveland Clinic) opened the session by reviewing metabolic and toxic myelopathies. The most common metabolic myelopathy discussed was Vitamin B12 deficiency, classically producing subacute combined degeneration. Clinically, these patients typically present with symmetric myelopathic symptoms in the distal lower extremities with concurrent hyperreflexia and gait abnormalities. On MRI, this condition correlates with long-segment T2 hyperintensity in the lateral and posterior columns of the cervical and upper thoracic cord. In isolation, such imaging findings could be mistaken for an intramedullary neoplasm, underscoring the importance of factoring in the overall clinical picture during the initial workup of any spinal lesion.
Dr. Krishnaney emphasized that identification of metabolic myelopathies hinges on identifying risk factors and exposure events. B12 deficiency and the closely related entity of nitrous oxide toxicity can present nearly-identically, with perioperative exposure to nitrous oxide as a classic precipitant of myelopathic symptoms in patients with near-normal serum B12 levels. Copper deficiency can develop after gastrectomy, and Vitamin E deficiency can be differentiated from B12 deficiency by the clinical presence of hyporeflexia in Vitamin E deficiency. Altogether, these examples served to reinforce the value of a detailed history and physical exam at the start of any diagnostic workup.
The presentation then turned to the imaging characteristics of several toxic myelopathies, including heroin-associated myelopathy and chemotherapy-induced myelopathy, with an emphasis on how some toxic myelopathies can produce overlapping imaging findings with inflammatory, neoplastic, and metabolic conditions. Radiation myelopathy was also reviewed, with delayed radiation myelopathy emphasized as a particularly feared complication of radiotherapy manifesting 6+ months after treatment and as a diagnosis of exclusion.
Dr. Krishnaney concluded with a discussion of pseudotumors, beginning with the most common pseudotumor: tumoral calcinosis, of which the dialysis-related subtype is the most common variant. Dr. Krishnaney emphasized that these pseudotumors generally manifest as painful juxtaarticular calcified masses that respond well to surgical excision. Myositis ossificans was next discussed as an entity typically manifesting in males in their 20s-30s with tissue trauma as a risk factor; these lesions have an ambiguous appearance in their early phase that should motivate biopsy to rule out malignancy.
Importantly, due to the high rates of recurrence with premature resection, surgical management of myositis ossificans lesions will need to be delayed until 9+ months from their onset - at which point they typically will have developed their characteristic calcified rim on imaging.
Finally, inflammatory pseudotumors were presented as PET-avid lesions that occasionally manifest near the articular joints of the spine and usually are amenable to medical management alone.
Interesting Cases: What To Do with Difficult Presentations of Unknown Spinal Lesions Daniel Sciubba, MD
Dr. Daniel Sciubba (Northwell Health) focused on presenting a practical framework to approach indeterminate lesions after initial imaging. Across multiple cases, he outlined a systematic approach as follows: undertake appropriate oncologic staging, determine whether tissue diagnosis is necessary and feasible, and develop a treatment strategy as part of an interdisciplinary team.
Dr. Sciubba’s first case was a destructive cervical lesion encasing the vertebral artery, raising concern for malignancy. Before a surgical plan was developed, systemic staging helped rule out metastatic disease and a CT-guided biopsy ultimately established the diagnosis of chordoma. Formal staging in this manner permitted evidence-based surgical planning in this high-risk lesion, helping to inform the decision to sacrifice the involved vertebral artery and ultimately producing a favorable outcome for the patient.
Additional cases reiterated how multidisciplinary tumor board input can directly inform surgical management. For example, one young patient with biopsy-confirmed liposarcoma underwent additional staging and repeat biopsies at the behest of the tumor board, with neoadjuvant chemotherapy reducing tumor burden and ultimately facilitating a more-manageable en bloc resection of the mass.
Dr. Sciubba concluded by reemphasizing the importance of avoiding premature intervention on ambiguous lesions unless there is imminent neurologic compromise – and that taking time to stage disease appropriately, consult colleagues including neuroradiology, and engage in multidisciplinary planning is invaluable. Furthermore, he emphasized that the shared decision-making and accountability of a multidisciplinary framework can help give surgeons the confidence to approach ambiguous lesions as leaders within the care team.
Workup of the Unknown Spinal Lesion Matthew Goodwin, MD, PhD, FACSM
Dr. Matthew Goodwin (Washington University) developed these principles further by focusing on surgical timing in lesions with malignant potential. He reviewed the three primary indications for spinal tumor surgery – namely, curative resection, structural stabilization, and decompression – and discussed how the Neurologic, Oncologic, Mechanical, and Systemic (NOMS) and Spinal Instability Neoplastic Scale (SINS) scoring frameworks can guide surgical decision-making.
Dr. Goodwin first emphasized the importance of distinguishing tumors from infection or other pathology early in the evaluation. Classic imaging paradigms – such as disc space involvement suggesting infection and disc sparing favoring malignancy – were presented as useful but imperfect heuristics. Though Dr. Goodwin emphasized that new information should always prompt reassessment of this fundamental distinction, he nonetheless proposed it as a useful starting point as the workup and treatment of infection and malignancy diverge substantially in their management from that point.
Moving into lesions with malignant potential, Dr. Goodwin used cases to illustrate how proper understanding of the timeframe of the patient’s deficits can fundamentally change the sequence of events in oncologic spine care. Patients with stable deficits and intact spinal stability (ie, with low SINS scores) may allow for biopsy and multidisciplinary surgical planning, whereas progressive deficits within the past 24-48 hours should motivate expedited management, including emergent radiation or even urgent/emergent surgery.
Multiple examples were presented to demonstrate how timing reshapes the surgical management and oncologic workup hierarchy. One case successfully avoided surgery with radiation alone due to biopsy identifying radiosensitive myeloma, while another case required immediate surgical stabilization despite radiosensitive pathology due to gross spinal instability. Throughout his discussion, Dr. Goodwin emphasized the importance of multidisciplinary coordination as a tool to ensure compliance with the most up-to-date literature guidance and advances in systemic oncologic therapy.
Surgical and Nonsurgical Treatment of Benign Lesions of the Spine Produced by Jack Jennings, MD, PhD, presented by Larry Lo, MD
This presentation, developed by Dr. Jack Jennings (Washington University) and presented by Dr. Larry Lo (Northwell Health) highlighted how accurate diagnosis of benign spinal lesions – despite imaging features concerning for malignancy – can facilitate less-invasive percutaneous management strategies as part of a comprehensive spine care team.
One representative case involved a patient with C7 radiculopathy secondary to a lesion whose MRI, angiogram, and PET scans all displayed features concerning for malignancy. However, biopsy ultimately diagnosed a benign osteoid osteoma, allowing for successful percutaneous management by interventional radiology in lieu of surgery.
This presentation emphasized that while percutaneous interventions are mostly appropriate for osteoid osteomas, other benign but locally aggressive lesions, such as osteoblastoma, aneurysmal bone cysts, giant cell tumors, and aggressive hemangiomas, should be reviewed in a multidisciplinary tumor board prior to pursuing any surgical or percutaneous intervention.
Tumor or Something Else? Wende Gibbs, MD, MA
Dr. Wende Gibbs (Barrow Neurologic Institute) concluded the session by reviewing imaging mimics of spinal malignancy, emphasizing the importance of corroborative imaging findings and clinical history when approaching an unidentified lesion with concerning features.
She presented multiple cases of spinal coccidioidomycosis, a fungal infection endemic to the southwestern United States. Disseminated coccidioidomycosis involving the vertebrae, epidural space, or leptomeninges can mimic metastatic disease, myeloma, or lymphoma processes on MRI and CT. This mimicry can include alarming features such as lytic lesions, soft tissue involvement, and PET avidity; Dr. Gibbs even presented a case where this mimicry resulted in a decompressive surgery being pursued, with the subsequent discovery of the infection leading to an alteration of the management plan.
Dr. Gibbs also reviewed bone marrow necrosis as a clinical entity in the context of treated acute lymphoblastic leukemia (ALL) - emphasizing that use of a second modality, in this case PET, can sometimes contextualize lesions that are ambiguous for active malignancy. Additionally, she devoted time to a discussion of retroperitoneal fibrosis prior to transitioning to the Q&A session for all panel attendees.
Conclusion
Ultimately, this session emphasized that a structured, evidence-based, and multidisciplinary approach to unknown spinal lesions is the key to avoiding missed diagnoses. Rather than relying on pattern recognition of isolated pathognomonic imaging findings, clinicians should focus on isolating key elements from the patient's clinical and imaging history and focus on contextualizing these against temporal factors such as neurologic stability and available diagnostic modalities.
By integrating metabolic, oncologic, surgical, and neuroradiologic perspectives into this framework, the session provided a comprehensive foundation for spine providers to improve their practice and feel better equipped to manage unknown spinal lesions in their clinical environment.
Acknowledgements
The authors thank the session presenters for granting permission to develop this article and for generously sharing their session materials as reference content.