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Orthopedic Tumor Surgery Board Review MCQs: OITE & AAOS Master Bank Part 33

Essential Questions: Spinal Tumour Diagnosis & Treatment

23 Apr 2026 80 min read 133 Views
Illustration of questions spinal tumour - Dr. Mohammed Hutaif

Key Takeaway

Your ultimate guide to Essential Questions: Spinal Tumour Diagnosis & Treatment starts here. When investigating questions spinal tumour, initial steps include a detailed history, examination, whole spine MRI, and further imaging like a bone scan or CT chest/abdomen/pelvis to locate the primary source. Histological grading via biopsy is essential. Treatment decisions are guided by the Tokuhashi scoring system, which indicates a palliative approach for scores under 5, and resection consideration for scores above 9.

Comprehensive Exam


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Question 1

A 55-year-old female presents with a 4-month history of progressive radiating pain in her right leg and mild foot drop. MRI of the lumbar spine reveals an intradural-extramedullary tumor at L4-L5, which is T1 isointense, T2 hyperintense, and shows strong, homogeneous enhancement with gadolinium. Erosion of the adjacent pedicle is noted. Which of the following is the most likely diagnosis?





Explanation

The classic presentation of a slowly progressive radiculopathy combined with an intradural-extramedullary tumor that shows strong, homogeneous enhancement and associated bony erosion (enlarged neural foramen) is highly suggestive of a schwannoma. Meningiomas are also intradural-extramedullary but often show a dural tail sign and are more common in the thoracic spine in older females. Ependymomas and astrocytomas are intramedullary tumors. Neurofibromas are closely related to schwannomas but are more often associated with neurofibromatosis and can be plexiform.

Question 2

A 70-year-old male with a history of prostate cancer presents with new onset of severe mid-thoracic back pain, bilateral lower extremity weakness, and urinary retention. Neurological exam reveals a T8 sensory level and paraparesis (motor grade 2/5 bilaterally). What is the MOST appropriate initial management step?





Explanation

This patient presents with signs and symptoms of acute spinal cord compression due to suspected metastatic disease. The priority is to prevent further neurological deterioration. High-dose IV corticosteroids (Dexamethasone) should be administered immediately to reduce edema around the spinal cord, and an emergent MRI of the entire spine is crucial to delineate the extent of compression, identify instability, and guide definitive treatment. Surgical decompression or radiation therapy will be considered after imaging and patient assessment, but steroids and imaging are the initial, most time-sensitive steps. Plain radiographs are insufficient for diagnosing spinal cord compression.

Question 3

Which of the following spinal tumor types is typically intramedullary and often associated with syringomyelia or cyst formation, particularly in the cervical spine?





Explanation

Ependymomas are the most common intramedullary spinal cord tumors in adults, frequently found in the cervical and cervicothoracic regions. They are well-known for their association with intratumoral hemorrhage and the formation of syrinx cavities, or cysts, both rostral and caudal to the tumor, due to altered CSF flow dynamics. Meningiomas and schwannomas are typically intradural-extramedullary. Chordomas and osteosarcomas are extradural, bone-forming tumors.

Question 4

Regarding the surgical management of metastatic spinal tumors, the Spine Instability Neoplastic Score (SINS) is used to guide treatment. Which score range typically indicates overt instability requiring surgical stabilization?





Explanation

The SINS score is a validated tool to assess spinal stability in patients with neoplastic disease. A score of 0-6 indicates stability, 7-12 indicates indeterminate stability, and 13-18 indicates overt instability. Therefore, a score above 7 (i.e., 8 or higher) typically suggests a need for surgical stabilization, although scores in the indeterminate range often warrant careful consideration and surgical consultation. A score above 12 definitely indicates overt instability, but the cutoff for considering intervention starts earlier.

Question 5

A 30-year-old female presents with progressive spastic paraparesis, gait disturbance, and dissociated sensory loss (loss of pain and temperature sensation with preserved touch and proprioception) in her upper extremities. MRI of the cervical spine reveals an enhancing intramedullary lesion extending from C3 to C6 with a large associated syrinx. The most likely diagnosis is:





Explanation

The clinical picture of progressive spastic paraparesis, gait disturbance, and dissociated sensory loss (syringomyelic pattern) in the context of an enhancing intramedullary lesion with a large syrinx is classic for an ependymoma. While astrocytomas can also be intramedullary and cause similar symptoms, ependymomas are more commonly associated with prominent syrinx formation and are the most common intramedullary tumor in adults. Meningiomas and schwannomas are intradural-extramedullary. Transverse myelitis is an inflammatory condition and typically has a more acute onset, though imaging might show enhancement.

Question 6

Which primary bone tumor of the spine is most commonly found in the sacrum and clivus, and is characterized by its local aggressiveness and high recurrence rates despite appearing histologically benign?





Explanation

Chordomas are rare, slow-growing malignant tumors derived from notochordal remnants. They have a predilection for the axial skeleton, particularly the sacrum (50-60%) and the clivus (30-35%), but can occur anywhere along the spine. They are known for their local aggressiveness, high local recurrence rates, and challenging surgical resection due to their location, despite often appearing histologically benign. Osteosarcoma, chondrosarcoma, and Ewing's sarcoma can affect the spine but have different epidemiological and anatomical distributions. Giant cell tumors are benign but locally aggressive, typically affecting long bones, and less commonly the spine.

Question 7

A 45-year-old male presents with chronic back pain. Imaging reveals a lytic lesion in a vertebral body. A biopsy confirms metastatic renal cell carcinoma. The patient has no neurological deficits. Given the high vascularity of renal cell metastases, which pre-operative measure is often considered to reduce surgical blood loss?





Explanation

Metastases from renal cell carcinoma, thyroid carcinoma, and pheochromocytoma are notoriously hypervascular. Pre-operative embolization of the tumor's feeding arteries, typically performed by interventional radiology 24-72 hours before surgery, can significantly reduce intraoperative blood loss and improve the safety and feasibility of resection. Chemotherapy, corticosteroids (unless cord compression), or radiation therapy do not directly address intraoperative bleeding from hypervascular lesions. Immediate surgery without embolization carries a high risk of catastrophic hemorrhage.

Question 8

According to the Enneking staging system, modified for spinal tumors, an Enneking stage III tumor (intracapsular benign) would be managed differently from a stage IA tumor (low-grade malignant, intracompartmental). Which of the following best describes the goal of surgical treatment for an Enneking Stage II (benign, extracompartmental) lesion?





Explanation

The Enneking staging system guides surgical margins. For an Enneking Stage I lesion (latent benign), intralesional curettage might suffice. For Stage II (active benign/extracompartmental), the goal is a marginal excision, where the tumor is removed en bloc with a minimal rim of surrounding normal tissue. This aims to remove the tumor completely while preserving vital structures. Stage III (aggressive benign) and Stage IA/IB (low-grade malignant) lesions often require a wide en bloc resection, aiming for a broader margin of healthy tissue. Radical resection is for high-grade malignancies or highly aggressive tumors where a 'dirty' margin is unacceptable. Palliative decompression is for advanced metastatic disease with neurological compromise.

Question 9

A 60-year-old patient with a known history of lung cancer develops new back pain. MRI shows an epidural mass compressing the spinal cord at T10. There is no neurological deficit beyond mild sensory changes. What is the most appropriate treatment strategy for optimal local control and quality of life?





Explanation

For patients with good performance status, limited epidural compression, and radiosensitive tumors (like lung cancer), SBRT has emerged as a preferred treatment modality. SBRT delivers high-dose, highly conformal radiation in fewer fractions, offering excellent local control with less toxicity compared to conventional external beam radiation, and can often spare patients from extensive surgery, especially if they have mild or no neurological deficits. Emergent surgery is reserved for severe or rapidly progressing neurological deficits, spinal instability, or radioresistant tumors. Conventional radiation is an option but SBRT offers better local control. Chemotherapy is systemic, not primary for local compression, unless very chemosensitive tumor. Conservative management is inappropriate for spinal cord compression.

Question 10

Which of the following characteristics is most consistent with a diagnosis of vertebral hemangioma on MRI?





Explanation

Vertebral hemangiomas are benign vascular tumors of the spine. On MRI, they are characteristically T1 hyperintense and T2 hyperintense due to their high fat content within the vascular channels. The 'polka dot' appearance on axial CT (due to thickened vertical trabeculae separated by fatty marrow) and the 'corduroy' sign on sagittal radiographs are classic, which correlate to high signal areas on MRI. Other options describe meningiomas (dural tail), blastic metastases (sclerotic), or aggressive malignant lesions (expansile lytic).

Question 11

A 10-year-old child presents with an expansile, lytic lesion involving the vertebral body and posterior elements of L3, with associated paraspinal soft tissue mass. Biopsy reveals small round blue cells with prominent vascular channels. Immunohistochemistry is positive for CD99 and EWSR1 rearrangement. What is the most likely diagnosis?





Explanation

The clinical presentation in a child (age 10), the location (vertebral body and posterior elements), the lytic-expansile nature with soft tissue mass, and especially the histological findings of small round blue cells with CD99 positivity and EWSR1 gene rearrangement are pathognomonic for Ewing's Sarcoma. Osteosarcoma and chondrosarcoma have different histological features. Rhabdomyosarcoma is a soft tissue sarcoma. Neuroblastoma can present similarly but has different immunohistochemical markers (e.g., positive for N-myc, negative for CD99) and is more common in younger children.

Question 12

What is the most common primary malignant tumor of the spine in adults?





Explanation

Multiple Myeloma is the most common primary malignant tumor involving bone in adults, and the spine is a frequently affected site. It is a hematologic malignancy characterized by the proliferation of plasma cells. While chordoma, osteosarcoma, chondrosarcoma, and Ewing's sarcoma are also primary malignant bone tumors of the spine, they are individually much rarer than multiple myeloma. Ewing's sarcoma is more common in adolescents and young adults.

Question 13

A patient undergoes surgical resection of a sacral chordoma. What is the most critical surgical principle to minimize local recurrence rates?





Explanation

For chordomas, local recurrence is the most significant challenge. The single most important factor in preventing local recurrence is achieving wide surgical margins through an en bloc resection, removing the tumor in one piece surrounded by healthy tissue. Intralesional resection (curettage) or marginal resection significantly increases recurrence risk. While adjuvant radiation (especially proton therapy) is often used, it is secondary to the quality of the initial surgical resection. Laminectomy is for decompression, not tumor eradication. Chemotherapy has limited efficacy for chordomas.

Question 14

Which of the following tumors is most commonly found at the conus medullaris or filum terminale and often presents with symptoms of cauda equina syndrome?





Explanation

Ependymomas, particularly the myxopapillary subtype, have a strong predilection for the conus medullaris and filum terminale. They typically present with symptoms of cauda equina syndrome, including low back pain, radicular pain, saddle anesthesia, and bowel/bladder dysfunction, due to compression of the nerve roots. Cervical astrocytomas are intramedullary but higher up. Thoracic meningiomas are intradural-extramedullary but at a different level. Lumbar schwannomas can cause cauda equina symptoms but are less specific to the filum terminale. Sacral chordomas are bone tumors and extradural.

Question 15

The presence of a 'dural tail sign' on contrast-enhanced MRI is highly suggestive of which intradural-extramedullary spinal tumor?





Explanation

The 'dural tail sign' refers to linear enhancement of the dura mater extending away from an intradural mass. While not pathognomonic, it is highly characteristic of spinal meningiomas, reflecting hypervascularity or tumor infiltration of the dura. Schwannomas can also be intradural-extramedullary but rarely present with a dural tail. Ependymomas and astrocytomas are intramedullary. Hemangioblastomas are typically intramedullary or cerebellar.

Question 16

What is the primary role of high-dose corticosteroids in the initial management of acute spinal cord compression due to metastatic disease?





Explanation

High-dose corticosteroids, such as Dexamethasone, are given for acute spinal cord compression primarily to reduce the inflammatory response and vasogenic edema surrounding the metastatic tumor. This reduction in edema can temporarily relieve pressure on the spinal cord, potentially preserving neurological function while definitive treatment (surgery or radiation) is planned. They do not directly shrink the tumor, regenerate nerves, or act as primary chemotherapy.

Question 17

Which of the following primary spinal tumors is most radiosensitive?





Explanation

Ewing's Sarcoma is known to be highly radiosensitive, and radiation therapy often plays a significant role in its treatment, either as definitive therapy or as an adjuvant to surgery. Chordomas and chondrosarcomas are generally considered radioresistant or require very high doses (e.g., proton therapy) for local control. Osteosarcoma and Giant Cell Tumor of Bone are also generally considered radioresistant in comparison to Ewing's.

Question 18

In a patient with a known history of breast cancer presenting with spinal metastasis and impending pathological fracture, what factor is most critical in determining the need for surgical intervention over non-operative management?





Explanation

The extent of cortical destruction, particularly involvement of the posterior column or pedicles, and the overall spinal instability are the most critical factors guiding surgical decision-making for metastatic spinal disease. Impending or actual pathological fractures, combined with instability, significantly increase the risk of neurological compromise and pain, thus warranting surgical stabilization. While other factors might influence overall management, instability is the primary driver for surgical intervention in this scenario.

Question 19

A 25-year-old male presents with recurrent acute attacks of severe back and leg pain, followed by periods of remission. MRI reveals multiple well-circumscribed, enhancing intradural-extramedullary lesions in the lumbar spine, some with a cystic component. These lesions are T1 isointense and T2 hyperintense. What is the most likely diagnosis?





Explanation

Multiple schwannomas (schwannomatosis) can present with recurrent attacks of pain and are typically intradural-extramedullary, well-circumscribed, and enhancing. The cystic component is also common in schwannomas. While neurofibromatosis can involve multiple nerve sheath tumors, schwannomatosis specifically refers to multiple schwannomas without evidence of NF2. Multiple meningiomas are rare in young adults without NF2. Hemangioblastomas are often intramedullary and associated with VHL disease. Disseminated ependymomatosis is rare and would typically be intramedullary in origin or CSF spread from a primary ependymoma.

Question 20

What is the typical imaging appearance of an osteoid osteoma in the spine on CT?





Explanation

Osteoid osteomas are benign bone-forming tumors characterized by a small, radiolucent nidus (typically < 1.5 cm) surrounded by a zone of dense reactive sclerosis. This appearance is best seen on CT. The nidus is the metabolically active part and often shows intense uptake on bone scan. The other options describe different types of lesions: Ewing's/metastasis (lytic with soft tissue), aneurysmal bone cyst ('soap bubble'), blastic metastasis (homogeneous blastic), and hemangioma (T1/T2 hyperintense).

Question 21

A patient with a vertebral body collapse due to metastatic disease undergoes posterior instrumentation for stabilization. Which of the following is considered a relative contraindication for surgery in this context?





Explanation

Surgical intervention for metastatic spinal disease, especially complex stabilization, carries significant risks and morbidity. An extremely short life expectancy (e.g., less than 3 months) is often considered a relative contraindication, as the potential benefits of surgery may not outweigh the risks and recovery time. In such cases, palliative measures, including radiation and pain management, may be more appropriate. Severe pain, neurological deficits, and single-level disease are generally indications for considering surgery, not contraindications. Radiosensitive tumors might favor radiation but don't preclude surgery if stability is paramount.

Question 22

Which of the following types of spinal metastases is typically considered 'radioresistant,' making surgical debulking or stabilization a more critical component of treatment?





Explanation

Renal cell carcinoma metastases are notoriously radioresistant, meaning they respond poorly to conventional external beam radiation therapy. In contrast, breast and prostate cancers, lymphoma, and multiple myeloma are generally considered radiosensitive. For radioresistant tumors, surgical options like decompression and stabilization become more critical, especially in the presence of neurological deficits or spinal instability, often followed by stereotactic body radiation therapy (SBRT) if possible.

Question 23

A 6-year-old child presents with progressive kyphosis and a painful scoliosis. Radiographs show a lytic, expansile lesion of the T7 vertebral body with 'blown out' appearance. Biopsy confirms an Aneurysmal Bone Cyst (ABC). What is the preferred treatment for an active, symptomatic ABC of the spine?





Explanation

Aneurysmal Bone Cysts are benign, but locally aggressive, highly vascular lesions. The standard of care for symptomatic or active ABCs of the spine typically involves pre-operative selective arterial embolization to reduce blood loss, followed by thorough intralesional curettage and bone grafting or cement augmentation. Observation is for quiescent lesions. Corticosteroid injections are less effective for large spinal ABCs. Radiation therapy is generally avoided in children due to the risk of radiation-induced malignancy and growth disturbance, used only in select, unresectable cases. Chemotherapy is not indicated.

Question 24

Which of the following statements about the clinical presentation of spinal meningiomas is FALSE?





Explanation

Spinal meningiomas are indeed more common in women (especially perimenopausal), typically cause slow, progressive deficits, and are most prevalent in the thoracic spine, often presenting with radicular pain. However, they are strongly associated with Neurofibromatosis Type 2 (NF2), not Type 1 (NF1). NF1 is more commonly associated with neurofibromas and optic pathway gliomas.

Question 25

In the context of spinal cord tumors, what anatomical location generally carries the worst prognosis due to surgical complexity and high risk of neurological deficit?





Explanation

Intramedullary spinal cord tumors (within the spinal cord substance itself) typically carry the worst prognosis in terms of surgical morbidity and potential for permanent neurological deficit. Their intimate relationship with neural tracts makes complete resection challenging without causing further damage. Extradural and intradural-extramedullary tumors, while serious, generally allow for safer surgical dissection planes. Sacral and conus medullaris locations are challenging but generally have better functional outcomes than intramedullary tumors of the cervical or thoracic cord.

Question 26

A 68-year-old patient with no prior cancer history presents with rapidly progressive back pain, bilateral leg weakness, and urinary incontinence. MRI shows a destructive lesion of the L3 vertebral body with significant epidural compression and pathological fracture. A CT-guided biopsy is pending. What is the most appropriate initial management step while awaiting biopsy results?





Explanation

The patient presents with signs of acute spinal cord compression (rapidly progressive neurological deficits, bladder dysfunction, pathological fracture, epidural compression). The immediate priorities are to stabilize neurological function and obtain definitive diagnosis. High-dose corticosteroids are critical to reduce cord edema. Although a biopsy is pending, the clinical urgency of cord compression necessitates immediate intervention regardless of precise tumor type, guided by imaging. Surgical decompression and stabilization is a strong consideration, but the first medical step is steroids and a definitive plan based on imaging. Antibiotics are for infection, chemotherapy is for systemic disease, and bed rest is insufficient.

Question 27

What is the typical presentation of an osteoblastoma of the spine?





Explanation

Osteoblastomas are benign bone-forming tumors that are histologically similar to osteoid osteomas but are larger (>1.5-2 cm) and generally less sclerotic. Unlike osteoid osteomas, the pain associated with osteoblastomas is often severe, poorly responsive to NSAIDs, and can be worse at night. Spinal osteoblastomas frequently involve the posterior elements and can cause a painful scoliosis, particularly in children and adolescents, due to muscle spasm. Night pain relieved by NSAIDs is characteristic of osteoid osteoma. Other options describe other conditions like disc herniation or spinal stenosis.

Question 28

A 75-year-old female presents with T7 vertebral body collapse and severe pain. Biopsy confirms metastatic breast cancer. She has mild weakness but no cord compression. Her SINS score is 10. What is the most appropriate management approach?





Explanation

The SINS score of 10 indicates indeterminate instability, meaning surgical consultation is warranted but not necessarily emergent. With mild weakness and no cord compression, SBRT is an excellent option for local control and pain relief for metastatic breast cancer, which is generally radiosensitive. SBRT offers superior local control and often prevents progression to overt instability compared to conventional EBRT, especially for single-level disease. Surgical decompression is not immediately indicated without severe cord compression or rapidly progressing deficits. Observation is insufficient for a SINS 10 and collapsed vertebra. Systemic chemotherapy treats the disease systemically, not the local instability or pain.

Question 29

Which of the following histological features is characteristic of a chordoma?





Explanation

The hallmark histological feature of a chordoma is the presence of physaliferous cells. These are large, vacuolated cells, often arranged in cords and lobules within a prominent myxoid (mucinous) extracellular matrix. This appearance reflects their notochordal origin. Small round blue cells are seen in Ewing's sarcoma and lymphoma. Plasmacytoid cells are seen in multiple myeloma. Spindle cells with palisading nuclei are characteristic of schwannomas. Cartilaginous matrix with entrapped chondrocytes characterizes chondrosarcoma.

Question 30

A patient is undergoing an en bloc spondylectomy for a primary malignant tumor of the thoracic spine. Which of the following intraoperative neuromonitoring modalities is most critical for detecting early spinal cord compromise?





Explanation

During complex spinal surgeries, especially those involving tumor resection and potential spinal cord manipulation, MEPs are crucial. MEPs directly assess the integrity of the descending motor pathways (corticospinal tracts) and are highly sensitive to detect ischemic or mechanical injury to the motor tracts. SSEPs monitor ascending sensory pathways but may not detect pure motor deficits. EMG monitors nerve root function. NCS is typically pre-operative. EEG is for brain activity. Therefore, MEPs are paramount for monitoring motor function during en bloc spondylectomy.

Question 31

Which of the following would be an absolute contraindication for proton beam therapy for a spinal tumor?





Explanation

Proton beam therapy is an advanced form of radiation that can deliver highly conformal doses while sparing surrounding critical structures, often used for tumors like chordomas or chondrosarcomas. However, it is a planned therapy that takes time. A significant neurological deficit requiring immediate surgical decompression is an absolute contraindication for delaying treatment for any radiation therapy, including proton beam. Other options are typically relative contraindications or challenges that can often be overcome (e.g., metallic artifacts can be managed with specific planning, prior radiation is a consideration but not absolute contraindication if re-irradiation is planned carefully, age is not a direct contraindication, large tumor volume is often an indication for, not contraindication against, advanced radiation techniques).

Question 32

Which of the following is the most common extradural primary tumor of the spine in adolescents and young adults, often presenting with bone pain, fever, and weight loss?





Explanation

Ewing's Sarcoma is a highly malignant primary bone tumor primarily affecting children, adolescents, and young adults. It typically presents with localized pain, swelling, and systemic symptoms such as fever, weight loss, and fatigue, mimicking infection. The spine is an uncommon but recognized site. Osteosarcoma and chondrosarcoma are more common in older adults or have different age peaks. Osteoid osteoma is benign. Multiple myeloma is a disease of older adults.

Question 33

A patient with a history of prostate cancer presents with a T12 vertebral body lesion. Biopsy confirms metastatic adenocarcinoma. The lesion is primarily blastic. On MRI, it is typically:





Explanation

Blastic metastases, such as those from prostate cancer (or sometimes breast), are characterized by increased osteoblastic activity. On MRI, these lesions typically appear T1 hypointense and T2 hypointense due to the replacement of normal fatty marrow with sclerotic bone and tumor cells, which have less free water. This contrasts with lytic lesions (e.g., renal cell, thyroid) that are often T1 hypointense and T2 hyperintense.

Question 34

Regarding Giant Cell Tumors (GCT) of the spine, which of the following statements is true?





Explanation

Giant Cell Tumors of Bone are locally aggressive benign tumors that commonly affect the epiphyses of long bones but can also involve the spine, particularly the sacrum and vertebral bodies. They are more common in young adults (20-40 years) after skeletal maturity. They have a high local recurrence rate, especially after intralesional curettage. Complete en bloc resection is ideal but often challenging in the spine. Denosumab (a RANK ligand inhibitor) is an important adjuvant therapy that can help in controlling the tumor, but chemotherapy is not the mainstay. They are not highly radiosensitive, and radiation is generally reserved for unresectable cases due to malignancy risk.

Question 35

What is the most frequent initial symptom of a primary spinal cord tumor (intramedullary)?





Explanation

Intramedullary spinal cord tumors (e.g., ependymomas, astrocytomas) typically grow slowly, causing insidious and progressive neurological deficits. Common initial symptoms include progressive sensory changes (numbness, paresthesias), gait disturbance, and motor weakness, often in a long-tract pattern. Acute onset paraplegia is rare. While localized pain can occur, it's often not the sole or most prominent feature initially. Radicular pain is more common with intradural-extramedullary or extradural lesions. Cauda equina syndrome is specific to lower lumbar/sacral regions, typically from conus or filum terminale tumors.

Question 36

Which of the following is an advantage of anterior surgical approach over a posterior approach for direct spinal cord decompression of an anteriorly located extradural tumor?





Explanation

The primary advantage of an anterior approach for an anteriorly located extradural tumor is the ability to achieve direct decompression of the spinal cord by removing the pathology from the front, and simultaneously reconstructing the anterior column (e.g., with cages and plates). Posterior approaches primarily provide indirect decompression and are better for posterior element tumors or stabilization. While anterior approaches can be very effective, they often carry higher risks (e.g., visceral injury, complex access) and are not necessarily 'easier' or lower risk of neurological injury compared to posterior in all cases. CSF leak risk depends on dural integrity.

Question 37

A patient presents with a sacral mass. Biopsy reveals a chondrosarcoma. Surgical planning indicates that a wide en bloc resection will likely require a sacrectomy with significant neurological deficit (bowel/bladder/sexual dysfunction). What is the primary role of high-dose proton beam radiation therapy in this scenario?





Explanation

Chondrosarcomas are generally considered radioresistant to conventional photon radiation. However, high-dose proton beam therapy, due to its ability to deliver high doses precisely, can be highly effective. If achieving wide surgical margins for a sacral chondrosarcoma would result in unacceptable morbidity (e.g., complete loss of bowel, bladder, and sexual function), proton beam therapy can be considered as the primary definitive treatment to achieve local control, often as a 'surgical alternative' where surgery is not feasible or would lead to unacceptably high morbidity. It can also be used adjuvant after marginal resection, or neoadjuvant, but its key role in radioresistant tumors like chondrosarcoma is as a potential primary definitive treatment.

Question 38

Which of the following conditions is most likely to present with 'skipping' or 'drop' metastases, often seen along the neuraxis in conjunction with a primary spinal cord tumor?





Explanation

Spinal ependymomas, particularly the higher-grade anaplastic subtypes, are known for their propensity to spread via CSF pathways, leading to 'drop metastases' or 'skipping lesions' at distant sites along the spinal cord or brain. This phenomenon is less common with meningiomas or schwannomas, which are typically localized intradural-extramedullary lesions. Osteosarcoma and chordoma are extradural bone tumors and spread via different mechanisms (hematogenous or direct invasion).

Question 39

In the Magerl-AO classification system for spinal fractures, which type of fracture is typically associated with a significantly increased risk of neurological injury when present with a tumor?





Explanation

The Magerl-AO classification system categorizes spinal fractures based on mechanism and stability. Type C fractures, representing translational injuries, involve disruption of all three spinal columns and are highly unstable. When associated with a tumor, these translational forces can lead to significant displacement and a very high risk of severe neurological injury due to direct impingement and shear forces on the spinal cord or cauda equina. While burst fractures (A3) also carry neurological risk, Type C represents a much higher degree of instability and neurological compromise.

Question 40

What is the most common histological subtype of spinal cord astrocytoma in adults?





Explanation

In adults, spinal cord astrocytomas are predominantly low-grade fibrillary astrocytomas (WHO Grade II). Pilocytic astrocytomas (WHO Grade I) are more common in children. Anaplastic astrocytomas (Grade III) and glioblastoma multiforme (Grade IV) are high-grade and rarer in the spinal cord compared to the brain. Subependymomas are typically benign ependymal tumors, distinct from astrocytomas.

Question 41

A 40-year-old male with a history of intravenous drug use and HIV presents with acute back pain, fever, and progressive paraparesis. MRI shows a L3 vertebral body lesion with epidural extension and significant cord compression. Given the clinical context, what is the most likely diagnosis, and what is the initial management priority after obtaining imaging?





Explanation

The clinical presentation (acute pain, fever, paraparesis, IVDU/HIV risk factors) combined with imaging of a destructive vertebral lesion and epidural compression points strongly towards pyogenic vertebral osteomyelitis with an epidural abscess. This is a surgical emergency requiring urgent decompression of the spinal cord (laminectomy or anterior debridement) and debridement of infected tissue, along with empiric broad-spectrum antibiotics, to prevent irreversible neurological damage and control infection. While other options represent potential diagnoses, the acute febrile presentation and risk factors make infection most likely and prioritize urgent surgical source control.

Question 42

Which of the following is considered a hallmark clinical feature differentiating an intramedullary spinal tumor from an extradural tumor?





Explanation

Early dissociated sensory loss (syringomyelic pattern), where pain and temperature sensation are lost while touch and proprioception are preserved, is a hallmark feature of intramedullary lesions, especially those causing a syrinx or affecting the spinothalamic tracts crossing in the central cord. This is due to disruption of the decussating spinothalamic fibers. While other symptoms like motor weakness, pain, and bladder dysfunction can occur with any spinal tumor, this specific sensory pattern points strongly to an intramedullary pathology.

Question 43

What is the primary utility of a whole-body FDG-PET/CT scan in the workup of a suspected spinal tumor?





Explanation

Whole-body FDG-PET/CT is highly valuable in oncology for assessing metabolic activity. Its primary utility in the context of spinal tumors is to stage known malignancies by detecting distant metastases or multifocal disease. In cases of suspected metastatic spinal tumor from an unknown primary, it can help identify the primary tumor site (e.g., lung, colon). While it can help differentiate benign from malignant lesions (malignant lesions typically show higher FDG uptake), and can be incorporated into surgical planning, its main strength is systemic staging and primary tumor identification for metastatic disease. MRI is superior for spinal cord anatomy; CT is better for bony detail and stability.

Question 44

A patient is diagnosed with a sacral chondrosarcoma. The tumor is large, involving multiple segments of the sacrum, and would require a high sacrectomy with complete loss of bowel and bladder function. The patient declines this highly morbid surgery. What alternative treatment modality offers the best chance for local control?





Explanation

Chondrosarcomas are generally considered radioresistant to conventional photon radiation, and chemotherapy has limited efficacy. For large, unresectable, or high-morbidity sacral chondrosarcomas where surgery is declined, high-dose proton beam therapy is considered the best alternative for local control. Proton therapy's unique Bragg peak allows for highly conformal dose delivery to the tumor while minimizing dose to adjacent critical structures, making it superior to conventional radiation for these tumors. Intralesional injections are not suitable for large chondrosarcomas.

Question 45

What is the approximate percentage of patients with systemic cancer who will develop spinal metastases?





Explanation

Spinal metastases are a very common complication of systemic cancer. It is estimated that approximately 30-40% of patients with systemic cancer will develop spinal metastases during their disease course. This number varies depending on the type of primary cancer, but the spine is the most common site of bone metastasis. Options A and B are too low, and options D and E are too high as a general estimate.

Question 46

Which of the following describes the most common location for primary spinal astrocytomas in adults?





Explanation

Spinal cord astrocytomas, like ependymomas, are intramedullary tumors. While they can occur anywhere, they show a slight predilection for the cervical and cervicothoracic regions in adults. Ependymomas are more common at the conus medullaris/filum terminale. Therefore, cervical spine is the most common location for primary spinal astrocytomas in adults.

Question 47

A 60-year-old male with a history of pancreatic cancer presents with new-onset back pain and recent onset of bilateral leg weakness. MRI shows a metastatic lesion at T10 with moderate spinal cord compression. His performance status is good (KPS 80). Which of the following factors would MOST strongly favor surgical decompression over radiation alone?





Explanation

Rapidly progressive neurological deficit is a critical indication for urgent surgical decompression. While radiation can be effective, it often has a slower onset of action and may not be sufficient to prevent irreversible neurological damage in cases of rapid decline. Pancreatic cancer is generally radioresistant, further favoring surgery. Single-level disease and good performance status make surgery more feasible. Prior radiation to the same segment would make re-irradiation risky or less effective, also favoring surgery. Absence of pain might make the decision more nuanced, but rapid neurological progression is paramount.

Question 48

Which histological finding is characteristic of a spinal osteosarcoma?





Explanation

The defining histological characteristic of osteosarcoma is the direct production of osteoid (immature bone) or bone by malignant mesenchymal cells (spindle cells). Chondroid matrix is seen in chondrosarcoma. Small round blue cells are characteristic of Ewing's sarcoma. Sheets of plasma cells are for multiple myeloma. Physaliferous cells are for chordoma.

Question 49

A patient develops new onset of bladder dysfunction and saddle anesthesia following surgery for an intradural-extramedullary lumbar spine tumor. These symptoms are most indicative of injury to which of the following structures?





Explanation

Bladder dysfunction (urinary retention or incontinence) and saddle anesthesia (loss of sensation in the perineal and inner thigh region) are classic symptoms of cauda equina syndrome. In the lumbar spine, below the conus medullaris (typically L1-L2), the spinal cord terminates, and the nerve roots of the cauda equina descend. Injury to these nerve roots during surgery for a lumbar intradural-extramedullary tumor (e.g., schwannoma, meningioma) can cause these deficits. Injury to the spinal cord itself would cause upper motor neuron signs (spasticity, hyperreflexia). Cervical or thoracic nerve roots would present with different neurological deficits.

Question 50

For patients with solitary spinal metastases from a chemosensitive and radiosensitive tumor (e.g., lymphoma, myeloma), who have no neurological deficits and stable spine, what is generally considered the primary treatment?





Explanation

For solitary spinal metastases from chemosensitive and radiosensitive tumors (like lymphoma or multiple myeloma), systemic chemotherapy and/or radiation therapy (conventional or SBRT) are typically the primary treatment modalities, especially if there are no neurological deficits and the spine is stable. These tumors often respond well to non-surgical treatment, allowing for disease control without the morbidity of surgery. Surgical resection is usually reserved for radioresistant tumors, instability, or neurological compromise. Observation is insufficient for malignancy. Kyphoplasty/vertebroplasty are for pain from vertebral compression fractures, not primary tumor treatment.

Question 51

What is the typical age group and spinal location for a spinal hemangioblastoma?





Explanation

Spinal hemangioblastomas are rare, benign, highly vascular intramedullary tumors. They are most commonly seen in young to middle-aged adults, and their most frequent location is the thoracic spine, followed by the cervicomedullary junction and cervical spine. They are often associated with Von Hippel-Lindau (VHL) disease, in which case they can be multifocal. Pediatric cases are rare, and elderly onset is less common. Diffuse multifocal throughout the entire spine is primarily seen in VHL. Therefore, young to middle-aged adults, thoracic or cervicomedullary junction, is the most typical.

Question 52

Which type of metastatic lesion to the spine is most commonly associated with a 'blastic' appearance on plain radiographs and CT scans?





Explanation

Prostate carcinoma metastases are classically osteoblastic or 'blastic,' meaning they stimulate bone formation, leading to increased bone density visible on radiographs and CT. Breast cancer metastases can also be blastic, lytic, or mixed. Renal cell, thyroid, and lung carcinomas are typically lytic (bone-destroying). Multiple myeloma causes 'punched-out' lytic lesions without reactive sclerosis.

Question 53

Regarding intramedullary spinal cord astrocytomas, what is a key prognostic factor influencing surgical outcome and long-term survival?





Explanation

For both ependymomas and astrocytomas, the extent of surgical resection is the most critical prognostic factor. Gross total resection (GTR) is strongly associated with significantly improved long-term survival and reduced recurrence rates compared to subtotal resection (STR). While pre-operative neurological status influences initial morbidity, and age can play a role, the completeness of tumor removal is paramount for biological control. Syrinx size is a symptom, not a primary prognostic factor in itself for the tumor. Hydrocephalus is rare with spinal cord tumors unless secondary to CSF pathway obstruction.

Question 54

Which of the following scenarios would MOST strongly contraindicate an open biopsy for a suspected spinal tumor, favoring percutaneous CT-guided biopsy or FNA?





Explanation

For highly vascular lesions, such as suspected renal cell carcinoma metastases, an open biopsy carries a significant risk of severe hemorrhage. In these cases, a percutaneous CT-guided biopsy, often with prior embolization, is generally preferred due to its minimally invasive nature and lower bleeding risk. While open biopsy provides a larger specimen, the risk of bleeding in a hypervascular lesion can be catastrophic. Large, accessible masses, failed percutaneous attempts, or the need for immediate surgical guidance are often indications for open biopsy. Lymphoma biopsy requires adequate tissue, which can sometimes favor open, but hypervascularity is a definite contraindication to routine open approach.

Question 55

What is the most common primary site for metastatic tumors to the spine in males?





Explanation

In males, prostate cancer is the most common primary site for metastatic disease to the spine, often presenting with blastic lesions. Lung cancer is also very common in both sexes. In females, breast cancer is the most common primary site. Kidney and thyroid cancers also frequently metastasize to the spine but are less common overall than prostate in males.

Question 56

A patient with a known metastatic lesion to the spine presents with excruciating back pain unrelieved by narcotics, but no neurological deficit. Imaging shows a lytic lesion with cortical destruction but no clear instability based on SINS. What is a reasonable initial management step to address the severe pain?





Explanation

For metastatic spinal lesions causing severe pain, even without neurological deficit or clear instability, radiation therapy (either conventional external beam radiation therapy - EBRT - or stereotactic body radiation therapy - SBRT) is highly effective for pain control. Many metastatic lesions are radiosensitive, and radiation can significantly reduce tumor burden and inflammation, leading to pain relief. Immediate surgery is not indicated without neurological compromise or overt instability. Chemotherapy is systemic. Observation is inappropriate for excruciating pain. Hospice is premature if active pain management is possible.

Question 57

Which of the following features on MRI is most characteristic of a myxopapillary ependymoma of the filum terminale?





Explanation

Myxopapillary ependymomas are typically found at the conus medullaris or filum terminale. On MRI, they are characteristically well-circumscribed, lobulated, and show strong homogeneous enhancement. A key feature is the presence of peripheral hemosiderin capping or intratumoral hemorrhage, often seen as T1/T2 signal changes due to blood products, resulting from their high vascularity and tendency to bleed. A large syrinx is more typical of higher cervical/thoracic ependymomas. Fluid-fluid levels are characteristic of ABC. Dural tail is for meningioma. Heterogeneous enhancement with peritumoral edema is less specific.

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Dr. Mohammed Hutaif
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