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Chapter 27: Surgical Management of Spinal Neoplasia 239

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Figure 27.7 Intradural/extramedullary peripheral nerve sheath tumor (arrows in A, B) in a dog: (A) sagittal and (B) transverse T2‐weighted MRI.

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Figure 27.8 Nephroblastoma (arrows in A, B) in a dog: (A) dorsal T1‐weighted MRI; (B) sagittal T1‐weighted fluid‐attenuated inversion recovery
(FLAIR) MRI.

pancreatic adenocarcinoma, rhabdomyosarcoma, Sertoli cell carci- Hemangiomas, meningiomas (Figure 27.2), and nerve sheath
noma, squamous cell carcinoma, transitional cell carcinoma, pros- tumors (Figure 27.7) are the most common type found in this
tatic carcinoma, and thyroid carcinoma have all been reported to location [6,7].
metastasize to the spine [6]. Therefore additional testing (such as Intramedullary tumors (Figure 27.3) are the least common,
chest and abdominal radiographs, abdominal ultrasound and, if accounting for about 15% of cases. Clinically, patients with tumors
possible, thoracic CT when appropriate) should be considered if in this location typically do not present with pain. These tumors
primary or metastatic disease has occurred in the specific patient. usually arise from cellular components of the normal spinal cord.
Of the primary soft tissue extradural spinal tumors, lymphoma is Primary glial tumors such as astrocytoma, choroid plexus papil-
the most common seen in dogs. Meningioma and nerve sheath loma, ependymoma, oligodendroglioma, and undifferentiated sar-
tumors are also common in the dog. Other soft tissue tumors coma have all been reported [8].
reported in this location in dogs are myxosarcoma, myxoma, Extrarenal nephroblastomas (Figure 27.8) are rare tumors that
lipoma, and plasma cell tumor [7]. have been located either in the intradural/extramedullary space or
Intradural/extramedullary tumors are the second most common intramedullary. They have also been termed as ependymoma, neu-
spinal tumor, accounting for about 35% of cases. They are found in roepithelioma, and medulloepithelioma. They are most common in
the subarachnoid space, being confined by the dura mater. While young dogs (5–36 months old), especially the German Shepherd.
some of the tumors in this location can be associated with pain Typically, these tumors are found between T10 and L2. In general
from compression, not all of these dogs and cats exhibit pain. they are located dorsal or lateral to the spinal cord [6,9–11].