Hemangioblastoma

From Dog
Spinal cord hemangioblastoma in a dog, showing an intramedullary bulging mass abutting the pia mater[1]

Hemangioblastomas are a rare benign highly-vascular neuroaxial neoplasms of dogs composed of a mixture of neoplastic stromal cells embedded in a rich capillary network.

Hemangioblastomas have a tendency to be cystic lesions with a mural nodule. Pure solid tumors are less common than cystic tumors[2]. Peritumoral edema is common in these tumors[3].

Although the cause of these tumors is unknown, they have been diagnosed in pups exposed to nitrosethylurea in utero, suggesting a teratogenic origin to this tumor[4].

In humans, these tumors are associated with Von Hippel-Lindau disease, an autosomal-dominant hereditary syndrome that affects multiple organ systems including renal cell carcinomas and cysts, pancreatic carcinomas and cysts, pheochromocytomas, and epididymal cystadenomas[5]. This syndrome has not been reported in dogs.

Hemangioblastomas usually develop within the canine cerebellum or spinal cord as either single or multiple tumors.

Affected dogs usually present with neurological symptoms associated with a mass-effect upon the spinal cord or brain, and include progressive proprioceptive deficits, primarily the hindlimbs, ataxia and seizures.

Diagnosis usually requires MRI imaging or postmortem examination.

A definitive diagnosis requires histological examination of neoplastic tissue, which characteristically show thin-walled capillaries lined by endothelial cells and separated by pleomorphic cells (stromal cells) with a moderate degree of anisokaryosis[1].

Immunohistochemically, the endothelial cells are positive for factor VIII-related antigen and the stromal cells are positive for neuron-specific enolase and vimentin.

A differential diagnosis would include other brain tumors such as meningioma.

These tumors are relatively invasive and surgical excision, though it may resolve clinical symptoms, may not be curative.

Radiation therapy is an option for poor surgical candidates[6].

References

  1. 1.0 1.1 Cantile C et al (2003) Intramedullary hemangioblastoma in a dog. Vet Pathol 40(1):91-94
  2. Sharma RR et al (1985) Supratentorial haemangioblastoma not associated with Von Hippel Lindau complex or polycytemia: Case report and literature review. Br J Neurosurg 9:81–84
  3. Rengachary SS & Blount JP (1996) Hemangioblastomas. In: Wilkins RH, Rengachary SS, editors. Neurosurgery. NewYork: McGraw-Hill; pp. 1205–19
  4. Napalkov NP et al (1981) Transplacental carcinogenic effect of n-nitrosoethylurea in dogs. Cancer Lett 12(1-2):161-167
  5. Maher ER et al (1990) Clinical features and natural history of von Hippel-Lindau disease. Q J Med 77:1151–1163
  6. Mohanty CB et al (2012) Brainstem hemangioblastoma and sellar mass. J Neurosci Rural Pract 3(3):429-430