Ch 37 - Neoplasms of the Vertebral and Spinal Cord Flashcards
Where is the most common location for spinal neoplasia?
- 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
Which neoplasms are highly radiation and chemo sensitive meaning surgery may not be a primary treatment?
- 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, chronic progressive myelitis, fibrosis/gliosis
- Radiation induced sarcoma
- Myokymia (involuntary muscle contractions - periodic botulinum toxin helpful to control clinical signs)
- Transient demyelination (difficult to distinguish from progressive disease)
- Do not resolve and can be life-threatening
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 (HSA, epithelial - thyroid, mammary, prostate, TCC)
What is unique about feline OSA?
Very low rate of mets regardless of location
If local control is possible, long-term survival is expected
What is the MST of dogs with vertebral OSA?
What has been associated with better survival?
MST 55-155d
- Better neuro status has been associated with better surgical outcome (330 vs 135d)
- Improved survival with adjunctive therapies (135 vs 38d)
- Better survival when treated with radiation (150 vs 15d)
What is the metastatic rate of vertebral OSA in dogs?
What are the chemo options?
- At least 40%
Chemotherapy options
- Platinum agents +/- doxorubicin
- Bisphosphonates/aminophosphonates
- Do not appear to have an effect on development of metastasis or survival….
What is the typical biological behaviour of spinal lymphoma?
- Infiltration of extradural masses into the adjacent meninges in over 90%
- Intramedullary lesions are rare
- 43% involve multiple CNS sites
- over 80% will have involvement of other extraneural sites
What is the prognosis for cats with spinal lymphoma treated with chemotherapy?
With prednisolone?
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 response to combination protocols
What is histiocytic sarcoma complex?
What breeds are commonly effected?
- 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
What is the MST of histiocytic sarcoma complex in dogs?
- For CNS involvement in 19 dogs, treatment with a variety of modalities resulted in MST of 3d…
- Other tissues/organs, MST 3-4 months
What is the local recurrence rate of surgically treated spinal infiltrative lipomas?
36 - 50%
What is a myxoma?
What breeds are overrepresented?
A rare, benign neoplasm arising from the synovium. More commonly arise from the appendicular joints however has been reported arising from the zygapophyseal joints
Dobermans and Labs overrepresented
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 (metastatic, dystrophic [+ iatrogenic], idiopathic).
- 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 above the dorsal arch of C1 and spinous process of C2)
- GSD overrepresented
What is osteochondroma(tosis)?
How does the presentation differ between cats and dogs?
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 ceasing 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
List the most common intradural-extramedullar masses
- Meningioma (arising from meningothelial cells from arachnoid membrane or pia mater)
- Nerve sheath tumours
- Extrarenal nephroblastoma
How are meningiomas graded?
Where is the most common location in dogs?
Grading:
- Grade I - benign
- Grade II - atypical
- Grade III - anaplastic (Rare)
In dogs, most commonly cranial to C3, then thoracic spinal cord. Cat mostly benign.
What is the difference in surgical resection of spinal meningiomas in comparison to intracranial meningiomas?
- Spinal meningiomas are often more adhered to nervous tissue
- Therefore gross resection is not always possible and may be cytoreductive
What is the MST of surgically treated spinal meningioma?
- 19 months (range 9m to over 4 years)
- Recurrence is common! - consider follow-up radiation
What biomarkers have been associated with a poorer outcome in dogs with incompletely intracranial meningiomas?
Increased proliferating cell nuclear antigen index
- Increased risk of recurrence
- Lower 2 year control rate
Increased VEG factor expression
- associated with shorted survival
What is the typical biologic behaviour of PNST
- Can be benign (rare) or malignant
- Locally aggressive with potential to invade the spinal cord
- Low rate of distant mets
- Rare in cats
What is the MST of dogs with Peripheral Nerve Sheat Tumours (PNST)?
- 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
What is a extrarenal nephroblastoma?
What staining is diagnostic?
Where is it almost exclusively found?
What are the two forms?
Extrarenal nephroblastoma is a neoplasm likely arising from mesonephris or metanephric embryolical remnants that become entrapped in developing dura and spinal cord
Positive immunohistochemical staining for Wilms’ tumour gene product (WT1)
Almost exclusively between T10-L2
Two forms/patterns - Glandular and solid
What is the main limitation of surgery with nephroblastomas?
Commonly invade into the spinal cord precluding complete resection
What is the MST of nephroblastoma treated with surgery +/- radiation?
With pred?
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
What are the most common primary and secondary intramedullary neoplasms?
Primary arising from:
- Ependyma
- Glia (astrocytoma, oligodendroglioma)
- Other neuroectodermal precursors
- Stromas origin (Primary Sarcoma)
Secondary
- Haemangiosarcoma
- Carcinoma
- “drop-metastasis” from choroid plexus carcinoma
In dogs, most common primary is ependymoma and astrocytoma. In cats, most common are glial neoplasma
What are the reported survival times following surgery for intramedullar neoplams?
3m to 70m
May provide palliation but very high risk!
