Neurocytoma

From Dog
A neurocytoma in a dog, showing pink nodular mass in the spinal column, adhering to the meninges[1]

Neurocytoma are a rare usually benign (or slow growing) neuronal tumor of the canine central nervous system, typically located intraventricularly near the foramen of Monro.

Extraventricular cerebral neurocytomas and spinal tumors have also been reported[1].

Because of their histopathologic similarity to oligodendrogliomas, historically, these tumors have also been classified as intraventricular oligodendrogliomas[2].

Neurocytomas are well-differentiated tumors, with a benign histologic appearance that displays various architectural patterns, even in the same specimen. The patterns most commonly seen are the honeycomb arrangement of oligodendroglioma and large fibrillary areas that resemble the irregular rosettes of pineocytoma[3].

Clinically affected dog with peripheral nervous system neurocytomas of the spinal cord invariably present with varying degrees of seizures, ataxia, proprioceptive deficits and eventual paresis.

A presumptive diagnosis can be made on imaging studies with CT or MRI scans, but a definitive diagnosis requires histological examination of biopsied material, showing expression of multiple neuronal markers, including neuron-specific enolase, synaptophysin, neural-cell adhesion molecule, and neuronal nuclear antigen within the tumors[4].

A differential diagnosis would include vertebral osteosarcoma or lymphoma and other neuronal tumors such as ependymoma.

Temporary remission of clinical signs may be achieved with dexamethasone or oral prednisolone but definitive treatment requires surgical intervention.

In humans, central neurocytoma tumor have a favorable prognosis with surgical debulking, but in dogs, the prognosis is considered poor as most cases advance rapidly.

With spinal cord neurocytomas, the prognosis is better, but despite surgical intervention dogs may be left with permanent neurological deficits.

References

  1. 1.0 1.1 Huisinga M et al (2008) Extraventricular neurocytoma of the spinal cord in a dog. Vet Pathol 45(1):63-66
  2. Sharma MC et al (2006) Neurocytoma: a comprehensive review. Neurosurg Rev 29:270–285
  3. llison D et al (2004) Neuropathology: A Reference Text of CNS Pathology, 2nd ed., pp. 677–680. Mosby, Edinburgh, UK
  4. Rossmeisl JH et al (2012) Clinicopathologic features of intracranial central neurocytomas in 2 dogs. J Vet Intern Med 26(1):186-191