Ch 37 Neoplasia of vertebrae and spinal cord

Question 1

Where is the most common location for spinal neoplasia?

Pain is the clinical sign most frequently displayed

Answer 1

Cervical spine
Extradural lesions account for at least 50%

Question 2

What are the most common biopsy techniques for vertebral neoplasia?

Answer 2

Jamshidi needle
Guided FNA if enough cortical lysis

fluoroscopic or CT guided

or via a surgical approach

Question 3

ddx

Answer 3

intervertebral disc herniation, cervical spondylomyelopathy, degenerative myelopathy, and degenerative lumbosacral disease.
Less common atlantoaxial malformation, meningomyelitis (infectious or noninfectious), discospondylitis, congenital or developmental malformation, trauma (vertebral fracture/luxation or brachial plexus trauma/avulsion), and ischemic myelopathy

Question 4

Dx neoplasia

Answer 4

complete blood count, chemistry profile, urinalysis, and, for cats, FeLV/feline immunodeficiency (FIV) testing.

three-view radiographic evaluation of the thorax and, in some cases, ultrasonographic evaluation of the abdomen aimed at excluding the presence of an underlying primary neoplasm

imaging
intradural/extramedullary lesions represent meningioma and nerve sheath neoplasms, and intramedullary neoplasms represent primary or secondary neoplasms.
MRI provides excellent discrimination of soft tissue structures with excellent spatial resolution. Images can be obtained in multiple anatomic planes without a loss of image quality
MRI can provide excellent discrimination of neoplasms from other disease processes.

radiographs are most useful for detection of primary or secondary vertebral neoplasms only if sufficient bone lysis is present.

Question 5

Which neoplasms are highlt radiation and chemo sensitive meaning surgery may not be a primary treatment?

Only limited information is available in the veterinary literature on outcomes following radiation

Answer 5

Lymphoma
Multiple myeloma

Question 6

What is the overall MST of spinal neoplasm treated with radiation?
What are early adverse effects of radiation?
Late adverse effects?

Answer 6

Overall MST 17m

Early adverse effects
- Occur in proliferating tissues such as epithelium and bone marrow
- Early morbidity uncommon

Late adverse effects (5%)
- Involve non-proliferating tissues (nervous system, vascular system and bone)
- White matter necrosis, haemorrhage or infarction, chroic progressive myelitis, fibrosis/gliosis
- Radiation induced sarcoma
- Myokymia (involuntary muscle contractions - botulinum toxin)
- Transient demyelination (difficult to distinguish from progressive disease)
- osteosarcoma
Do not resolve and can be life-threatening

Question 7

radiation

Answer 7

Typical definitive protocols for neoplasms of the vertebra and/or spinal cord in veterinary oncology consist of daily administration (Monday through Friday) of 18 to 22 treatments (fractions) for a total administered dose of 45 to 54 Gy. Palliative radiation therapy protocols are even more variable

Image-guided radiation therapy verifies the position of the neoplasm at each treatment and ensures accurate localization

most treated with external beam radiation therapy with a linear accelerator
newer technologies:
intensity-modulated radiation therapy
tomotherapy
stereotactic radiotherapy (also called radiosurgery - three-dimensional localization) samarium-153 ethylenediamine-tetramethylene phosphonic acid (EDTMP - radioisotope)

Question 8

chemotherapy

Answer 8

With the exception of lymphoma, plasma cell neoplasia, and osteosarcoma, only limited information is available about chemotherapy in treating neoplasms of the vertebrae or spinal cord.

Question 9

What are some limitations of chemotherapy in treating spinal neoplasms?

Answer 9

Many do not cross BBB
Unlikely to be used a primary treatment in neoplasms other than lymphona, leukaemia, multiple myeloma, disseminated histiocytic sarcoma

Question 10

List the most common forms of extradural neoplasia?

Answer 10

OSA (FSA, chondrosarcoma, HSA)

Lymphoma

Histiocytic sarcoma complex

Infiltrative lipoma

Multiple myeloma (multiple, well-circumscribed lytic lesions)

Myxoma

Tumoral calcinosis or calcinosis circumscripta

Osteochondroma

Metastatic (most commonly vascular or epithelial origin i.e. HSA, epithelial - thyroid, mammary, prostate, TCC)

Question 11

Dx

Answer 11

Radiographic findings include lysis, proliferative changes, and a mixed pattern of lysis and proliferation.
Pathologic fracture is possible.

similar regardless of the histologic type

presence of a soft tissue mass adjacent to the affected vertebra(e) is more commonly identified in secondary vertebral neoplasms.

hematopoietic neoplasms such as multiple myeloma and some metastatic neoplasms tend to affect more than one vertebra > characterized by multifocal well-circumscribed lytic lesions affecting multiple vertebrae

MRI > Lesions display variable changes in signal intensity that allow correct localization of the affected vertebra(e). In comparison to normal vertebrae, lesions are often hypointense on T1-weighted (T1W) images, hyperintense on T2-weighted (T2W) images, and demonstrate variability in enhancement after intravenous contrast administration.78 Unfortunately, degenerative and nonneoplastic pathologic processes may result in similar changes in signal intensity.

definitive diagnosis is based on histologic or cytologic evaluation

Question 12

Tx

Answer 12

Treatment of solitary primary vertebral neoplasms is focused on surgical resection. In most cases, only cytoreductive surgery is achievable

Vertebrectomy has been described in the dog.18,195 Despite this, little is known about the utility of the technique in clinical cases.

vertebrectomy necessitates not only technical expertise for surgical removal of the vertebra but also strict adherence to the same principles and considerations used in the management of vertebral fractures/luxations fractures to ensure adequate stability

result in decompression of the spinal cord and/or spinal nerves and nerve roots

Question 13

What is the MST of dogs with vertebral OSA?
What has been associated with better survival?

Answer 13

MST 55-155d

Treatment options include surgical resection, chemotherapy, definitive or palliative radiation therapy, and bisphosphonates or aminophosphonates alone or as multimodality therapy.

• Better neuro status has been associated with better surgical outcome (330 vs 135d)
• Improved survival with adjunctive therapies (135 vs 38d)
• Better survival when treatedwith radiation (150 vs 15d)

numbers of patients in each group were small, and these trends were not statistically significant

Question 14

What is the metastatic rate of vertebral OSA in dogs?
What are the chemo options?

Answer 14

At least 40%
Chemotherapy options
- Platinum agents +/- doxorubicin
- Bisphosphonates/aminophpsphonates
- Do not appear to have an effect on development of metastasis or survival….

Question 15

What is unique about feline OSA?

Answer 15

Very low rate of mets regardless of location

If local control is possible, long-term survival is expected

his neoplasm is associated with a low rate of metastasis in cats, so if local control is possible, long-term survival is expected. Survival times in three cats treated with surgery alone were 88, 109, and 518 days, but all three developed recurrence.9

Question 16

What is the typical biological behaviour of spinal lymphoma?

site in dog?
site in cat?

Answer 16

Infiltration of extradural masses into the adjacent meninges in over 90% in cats

Intramedullary lesions are rare

43% involve multiple CNS sites

over 80% will have involvement of other extraneural sites

DOG: Lymphoma involving the spinal cord in dogs occurs primarily as an epidural lesion. Most dogs present with acute neurological signs and rapid progressio

CAT: thoracic or lumbar regions of the spinal cord are commonly affected, and grossly, extradural lesions are most common

Question 17

What is the prognosis for cats with spinal lymphoma treated with chemotherapy?
With prednisolone?

dog?

large % cats/dogs extraneural involvement > image thorax and abdomen

Answer 17

Response rates to chemo 70-100%
- COP or CHOP (cyclophosphamide, doxorubicine, vincristine, pred)

Prednisolone may elicit short-term response of 1-2 months
- Pretreatment with pred may decrease the survival time of cats that responsd to combination protocols

median survival times have been <5 to 7 months, with the exception of some complete responders that have survived >1 year

DOG: surgery or radiation therapy, and the third dog, treated with chemotherapy, lived 730

majority of the dogs have been euthanized without treatment

Question 18

What is histiocytic sarcoma complex?
What breeds are commonly effected?

Answer 18

Neoplastic proliferation of cells of the dendritic or macrophage lineage
Can be localised or disseminated
Common breeds
- Bernese Mt Dog
- Golden Ret
- Rottweiler
- Flat-coated retriever

Can appear similar to vertbral OSA

Question 19

What is the MST of histiocytic sarcoma complex in dogs?

Answer 19

For CNS involvement in 19 dogs, treatment with a variety of modalities resulted in MST of 3d…
Other tissues/organs, MST 3-4 months

dogs with primary spinal cord involvement, localized and disseminated forms have been reported.
Lesions occur as intradural/extramedullary and/or as intramedullary lesions.

Question 20

What is the local recurrence rate of surgically treated spinal infiltrative lipomas?

Answer 20

36 - 50%

Question 21

infiltrative lipoma

CT/MRI appearance

Tx?

Answer 21

CT with a mean Hounsfield unit > fat.

MRI, adjacent fascial planes contain normal fat, demarcation of the borders of the neoplasm is challenging.
heterogeneously hyperintense on T2W and T1W images

Sx: It is impossible to obtain wide margin with the portion of the neoplasm that extends into the vertebral foramen.

limited reports suggest the potential for long-term control following surgery. With infiltrative lipoma elsewhere in the body, local recurrence is between 36% and 50%
Adjunctive radiation therapy may provide for improved local control.

Question 22

myxoma

A rare, benign neoplasm arising from the synovium, arising from the zygapophyseal joint of the articular processes of adjacent vertebrae have been described.

Answer 22

Too few reports exist to define a common signalment, predilection to occur at a site of a specific anatomic region of the vertebral column, or outcome with various therapeutic interventions.

MRI findings describe features that do not allow discrimination between myxoma and myxosarcoma

long term vontorl via hemilaminectomy if benign

doberman and lab overrespresented

Question 23

What is tumoral calcinosis or calcinosis circumscripta?
What are the primary Ca salts?

Answer 23

An uncommon disease in which there is ectopic mineralisation of soft tissues.
Ca salts consist of hydroxyapatite and amorphous Ca phosphate
Found in periarticular connective tissue, foot pads, tongue and vertebral column (particularly in the soft tissues abover the dorsal arch of C1 and spinous process of C2)
GSD overrepresented

Question 24

What is osteochondroma(tosis)?
How does the presentation differ between cats and dogs?

Answer 24

A benign lesion involving bones that develop by endochondral ossification. Believed to arise from the migration of chondrocytes from the physeal region to the metaphyseal region with continued cartilage formation.
Cartilaginous cap over the cortex of the bone is histologically diagnostic

Dogs:
- Tends to effect immature dogs with growth of lesions caesing with skeletal maturity
- Solitary or multiple lesions
- Potential for late malignant transformation to chondrosarcoma or osteosarcoma

Cats:
- Affects young adult cats
- Occurs in skeletally mature cats in any location, on any bone
- Continue to progress beyond skeletal maturity
- Associated with FeLV
- Can undergo malignant transformation to OSA

Question 25

List the most common intradural-extramedullar masses (3)

Answer 25

Meningioma (arising from meningothelial cells from arachnoid membrane or pia mater)

Nerve sheath tumours

Extrarenal nephroblastoma

Question 26

How are meningiomas graded?
Where is the most common location in dogs?
Dx?

Answer 26

Dx: presumptive diagnosis is suggested by imaging characteristics.

With myelography, the typical pattern associated with meningioma is intradural/extramedullary

On MRI, in comparison to the normal spinal cord, lesions typically are iso- to hypointense on T1W images, hyperintense on T2W images (expansion of the subarachnoid space is usually appreciated)

Grading:
- Grade I - benign
- Grade II - atypical
- Grade III - anaplasmic (Rare)

In dogs, most commonly cranial to C3

Question 27

What is the difference is surgical resection of spinal meningiomas in comparison to intracranial meningiomas?

minimum database, 3-view thoracic radiographs and abdominal ultrasound

Answer 27

Spinal meningiomas are often more adhered to nervous tissue

Therefore gross resection is not always possible and may be cytoreductive

in cases of invasive neoplasms, aggressive resection can lead to permanent neurological dysfunction.

durectomy is necessary for resection.

not close vs PSIS provides a scaffold of biocompatible material that promotes cellular ingress of fibroblasts and neovascularization from adjacent tissue

Question 28

What is the MST of surgically treated spinal meningioma?

Answer 28

19 months (range 9m to over 4 years)

Recurrence is common! - consider follow-up radiation
> 7 dogs received postoperative radiation therapy: Three experienced recurrence at 18, 27, and 36 months, respectively; two died of other causes at 72 and 78 months
> most reports involve megavoltage radiation, orthovoltage radiation

cats with meningioma involving the spinal cord suggest a potential for long survival but a high recurrence rate. median survival was 426 days (range, 211 to 842 days)

Question 29

What biomarkers have been associated with a poorer outcome in dogs with incompletely intracranial meningiomas?

Answer 29

Increased proliferating cell nuclear antigen index
- Increased risk of recurrence
- Lower 2 year control rate

Increased VEG factor expression
- associated with shorted survival

Question 30

What is the typical biologic behaviour of PNST

Answer 30

Can be benign (rare) or malignant

Locally aggressive with potential to invade the spinal cord
can arise along any part of the nerves from the nerve roots as they exit the spinal cord, the spinal or cranial nerves, or anywhere along the length of the nerve.

Low rate of distant mets
Rare in cats

Primary neoplasms arising from elements of the spinal nerves, named nerves of the limb, or cranial nerves or nerve roots have been referred to by a variety of names, including schwannoma, malignant schwannoma, Schwann cell neoplasm, neurofibroma, neurofibrosarcoma, neurilemoma, and neurinoma.

dog typically middle-aged or older.

Question 31

PNST CS, DX

Answer 31

chronic progressive unilateral lameness
> range from 2 weeks to 2 years, with the average duration of clinical signs from 5 to 6 months
> atrophy is often most evident in the supraspinatus and infraspinatus muscles.
> mass may be identifiable proximal in the axilla

Hypalgesia (neck, limb), Horner’s syndrome or an absent cutaneous trunci reflex may be present on the side ipsilateral to the affected limb.

The MRI
neuritis can be indistinguishable from those involving nerve sheath neoplasms
Compared to normal muscle, lesions are typically iso- to hypointense on T1W sequences and hyperintense on T2W sequences
Use of fat suppression techniques as tumor often appearce same as surrounding soft tissue
small lesion may be missed

Ultrasonography may allow visualization of nerve sheath neoplasms and guide needle aspiration or biopsy for neoplasms in the axilla. On ultrasound, neoplasms appear as tubular or round hypoechoic structures that cause deviation of the axillary artery from its fellow vein

In rare cases, exploratory surgery

Question 32

What is the MST of dogs with PNST?

Tx

Answer 32

Brachial plexus lesions treated with amputation alone 12m (DFI 7.5m)
Lesions involving spinal nerves/nerve roots MST 5m (DFI 1m)
Histologic grade, particulary MI per 10HPF has shown to be prognostic

Prognosis depends on interrelated factors, including location along the nerve, completeness of excision, and histologic assessment as benign versus malignant.

treatment of choice is surgical excision with wide margins.

imb-sparing surgery of the thoracic limb is contemplated, prior evaluation of radial nerve function is necessary,

Question 33

What is a extrarenal nephroblastoma?
What staining is diagnostic?
Where is it almost exclusively found?
What are the two forms?

age from 5 months to 7 years, with most between 6 and 36 months

Answer 33

Extrarenal nephroblastoma is a neoplasm likely arising from mesonephris or metanephric embryolical remnants that become entrapped in deeloping dura and spinal cord

Positive immunohistochemical staining for Wilms’ tumour gene product (WT1)

Almost exclusively between T10-L2

Two forms/patterns - Glandular and solid

Question 34

What is the main limitation of surgery with nephroblastomas?

Answer 34

Commonly invade into the spinal cord precluding complete resection

cytoreduction may alleviate clinical signs

Question 35

What is the MST of nephroblastoma treated with surgery +/- radiation?
With pred?

Answer 35

MST 70.5 - 374d
Pred -> MST 55d

One case report has a survival of 5.5yr after cytoreductive surgery and radiation therapy. At 5.5yr, dog developed a radiation-induced OSA

Question 36

What are the most common primary and secondary intramedullary neoplasms?

average duration of CS prior to presentation is often <3 weeks

Answer 36

Primary arising from:
- Ependyma
- Glia (astrocytoma, oligodendroglioma)
- Other neuroectodermal precursors
- Stromas origin (sarcomas)

Secondary
- Haemangiosarcoma
- Carcinoma
- “drip-metastasis” from choroid plexus carcinoma

In dogs, most common primary is ependymoma and astrocytoma. In cats, most common are glial neoplasma

Question 37

intramedullary Dx

Answer 37

MRI is necessary to adequately define the anatomic boarders of the neoplasm and identify secondary pathology such as edema or hemorrhage

diseases as primary or secondary neoplasia versus nonneoplastic pathology is not possible with imaging alone, animals with intramedullary lesions should undergo careful systemic screening

CSF > exclude inflammatory or infectious etiologies

FNA > high risk

Question 38

What are the reported survival times following surgery for intramedullar neoplams?

Answer 38

3m to 70m

May provide palliation but very high risk!

Question 39

Remission after complete excision of an intramedullary hemangioma with an identifiable tumor plane in a dog

Intradural extramedullary granular cell tumour in a cat

Myxoid meningioma in a dog

Question 40

Relationship between magnetic resonance imaging findings
and histological grade in spinal peripheral nerve sheath tumors
in dogs
Morabito 2023

Answer 40

Forty-four dogs with histopathological diagnosis of spinal PNSTs

Grade of malignancy was difficult to identify
based on diagnostic imaging alone. However, some MRI features were predictive of
high-grade PNSTs including tumor size and peripheral contrast enhancement.

Question 41

Cranial and vertebral osteosarcoma commonly has T2 signal heterogeneity, contrast enhancement, and osteolysis onMRI: A case series of 35 dogs
Tam 2022

Answer 41

multicenter, retrospective, case
series study, MRI studies of 35 dogs

large spectrum of variation. There was overlap of MRI findings between
osteosarcoma and other types of neoplasia.

Question 42

Long-Term Outcome After Surgical Resection of a
Spinal Choroid Plexus Tumor in a Dog
Yuya Saitoh

Answer 42

Spinal drop metastasis from a
primary intracranial CPT was suspected.

intradural-extramedullary mass lesion at the level of T12 and extradural spinal cord compression at L1-
L2. A hemilaminectomy was performed

Question 43

MRI Features of Solitary Vertebral Masses
in Dogs: 20 Cases (2010–2019)
Emilie Marine Hanot

Answer 43

A solitary vertebral mass was
significantly more likely to be malignant when the mass involved
the vertebral body, when the mass was T2W hyperintense and/or
STIR hyperintense and/or T1Whyperintense and/or hyperintense
on T1W gradient echo sequence, and if there was evidence of
cortical destruction. Conversely, a solitary vertebral mass was
more likely to be benign if the mass was hypointense on T1W
gradient echo sequence.