Web-Vet TM Neurology Specialists
Spinal Tumours
In this study the authors show the heterogeneous MRI and histopathological appearance of spinal lymphoma in 27 cats. All of them were evaluated for progressive neurological deficits, commonly acute or subacute, with paraparesis as the most common sign (62.9%), and pain present in 1/3 of the cases. In MRI studies spinal lymphomas were most commonly shown as a lumbar/lumbosacral epidural lesions, circumferential to the spinal cord, hyperintense on T2W images, and isointense on T1W images, with variable degrees of post-contrast enhancement and bone involvement. The majority of the lesions were focal (81.5%) but tended to extend to >1 vertebral body (66.6%). Antemortem diagnosis was achieved in 81.5% of cases via either CSF analysis, FNA or surgical biopsy.
Inaccurate localisation on MRI of a suspected neoplastic process as intramedullary (IM) as opposed to intradural-extramedulllary (IDEM) implies not only an inaccurate assumed histopathologic diagnosis but also inappropriate treatment recommendations and prognoses. This differentiation between IM and IDEM can be challenging as shown in this study which revealed considerable disagreement in designation of a lesion's relationship with the meninges.
The goals of this retrospective study were to describe the clinical, imaging, and histologic characteristics of canine primary spinal cord meningiomas, to evaluate surgical intervention and radiation therapy as treatment options, and to examine any correlation between tumor grade and clinical outcome.
Of 34 dogs with intraspinal mengiomas, most tumors were in the cervical spinal cord but were also found throughout the neuraxis. Location is correlated with histologic grade, with grade I tumors more likely to be in the cervical region than grade II tumors. Myelography generally shows an intradural extramedullary compressive lesion. On magnetic resonance imaging, the masses are strongly and uniformly contrast enhancing and a dural tail often is present. CSF analysis usually shows increased protein concentration with mild to moderate mixed pleocytosis. Surgical resection is an effective means of improving neurologic status, and adjunctive radiation therapy may lead to an improved outcome.
This study aimed to identify magnetic resonance imaging (MRI) features predictive of peripheral nerve sheath tumors (PNST) histologic grade in 44 dogs with histopathological confirmation.
16 dogs were PNSTs Grade 1 (low‐grade), 19 were PNSTs Grade 2 (medium‐grade), and 9 were PNSTs Grade 3 (high‐grade). Large volume and severe peripheral contrast enhancement were significantly associated with high tumor grade. Degree of muscle atrophy, heterogeneous signal and tumor growth into the vertebral canal were not associated with grade. Grade of malignancy was difficult to identify based on diagnostic imaging alone.
Clinical and magnetic resonance imaging features of lymphoma involving the nervous system in cats
This study of 31 cats aimed to describe the clinical and MRI features of lymphoma affecting the central (CNS) or peripheral (PNS) nervous system or both.
On MRI, lesions affecting the CNS were diagnosed in 18/31 cats, lesions in both CNS and PNS in 12/31, and lesions in the PNS only in 1/31. Intracranial lesions were diagnosed in 22 cats (extra‐axial, 7/22; intra‐axial, 2/22; mixed, 13/22), and spinal lesions were diagnosed in 12 (6/12 involving the conus medullaris and lumbosacral plexuses). Infiltration of adjacent extra‐neural tissue was present in 11/31 cases. Contrast enhancement was seen in all lesions, being marked in 25/30. Meningeal enhancement was present in all but 2 cases
The objectives of this study were to estimate sensitivity and specificity of MRI for (1) distinguishing between histopathologically confirmed intradural spinal cord disease versus degenerative myelopathy in dogs, (2) categorizing intradural spinal cord diseases as neoplastic, inflammatory, or vascular; and (3) determining tumor type within the etiologic category of neoplasia.
MRI had excellent sensitivity for diagnosis of intradural spinal cord lesions but specificity varied before and after provision of clinical data. MRI had good sensitivity (86.8%) and moderate specificity (64.7–72.5%) for diagnosing neoplasia. Sensitivity was lower for classifying inflammatory lesions but improved with provision of clinical data. Interrater agreement was very good for correctly diagnosing dogs with intradural lesions and good for diagnosing dogs with neoplasia.
Magnetic Resonance Imaging Features of Extradural Spinal Neoplasia in 60 Dogs and Seven Cats
This retrospective study describes the MRI features of extradural spinal neoplasia in 60 dogs and seven cats to identify potential distinguishing features between tumor classes and individual tumor types within each class.
In dogs, mesenchymal tumors were most common (48%), with undifferentiated sarcomas being the predominant tumor type. Round cell neoplasms were second most common (35%), with lymphoma and multiple myeloma/plasma cell tumor comprising the majority of cases.
The combined features that predicted round cell neoplasia (84%) included the preservation of vertebral shape, homogeneous contrast enhancement, and lesion centering on bone. The combined features that predicted mesenchymal neoplasia (73%) included altered vertebral shape, heterogeneous contrast enhancement, and lesion centering on paraspinal soft tissues.
The aim of this paper was to describe the distribution, clinicopathologic characteristics, radiographic findings, and clinical features of canine intramedullary spinal tumors evaluating 53 cases.
Intramedullary spinal cord tumors comprised 16% of all tumors of the spinal cord. Primary tumors were diagnosed in 66% of cases, with neuroepithelial-origin tumors comprising 51% of all primary neoplasms. Intraparenchymal metastases of transitional cell carcinoma and hemangiosarcoma accounted for 66% of all secondary tumors. Primary tumors were more likely to affect younger dogs.
Dogs with intramedullary metastases were most commonly presented for primary myelopathic signs. The majority of all tumors (52.8%) occurred in the T3-L3 spinal cord segments. All dogs with cervical neurolocalization had primary tumors. Dogs with metastatic lesions had a shorter duration of clinical signs before presentation, but there was no difference in survival time between dogs with primary as compared with secondary tumors.
