Ch 37 Neoplasia of vertebrae and spinal cord Flashcards
Where is the most common location for spinal neoplasia?
Pain is the clinical sign most frequently displayed
Cervical spine
Extradural lesions account for at least 50%
What are the most common biopsy techniques for vertebral neoplasia?
Jamshidi needle
Guided FNA if enough cortical lysis
fluoroscopic or CT guided
or via a surgical approach
ddx
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
Dx neoplasia
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.
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
Lymphoma
Multiple myeloma
What is the overall MST of spinal neoplasm treated with radiation?
What are early adverse effects of radiation?
Late adverse effects?
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
radiation
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)
chemotherapy
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.
What are some limitations of chemotherapy in treating spinal neoplasms?
Many do not cross BBB
Unlikely to be used a primary treatment in neoplasms other than lymphona, leukaemia, multiple myeloma, disseminated histiocytic sarcoma
List the most common forms of extradural neoplasia?
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)
Dx
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
Tx
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
What is the MST of dogs with vertebral OSA?
What has been associated with better survival?
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
What is the metastatic rate of vertebral OSA in dogs?
What are the chemo options?
At least 40%
Chemotherapy options
- Platinum agents +/- doxorubicin
- Bisphosphonates/aminophpsphonates
- Do not appear to have an effect on development of metastasis or survival….
What is unique about feline OSA?
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
What is the typical biological behaviour of spinal lymphoma?
site in dog?
site in cat?
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
What is the prognosis for cats with spinal lymphoma treated with chemotherapy?
With prednisolone?
dog?
large % cats/dogs extraneural involvement > image thorax and abdomen
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
infiltrative lipoma
CT/MRI appearance
Tx?
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.
What is tumoral calcinosis or calcinosis circumscripta?
What are the primary Ca salts?
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
How are meningiomas graded?
Where is the most common location in dogs?
Dx?
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
PNST CS, DX
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
