Vertebral Angiomatosis in a Dog

A 3 yr old spayed female Cavalier King Charles spaniel was referred for insidious ataxia and paraparesis. A thoracolumbar lesion was suspected. Computed tomography showed focal osteolysis of the vertebral body and pedicles of T5. In addition, a hyperdense, extradural material within the vertebral canal, causing spinal cord compression on the right side, was present. The lesion was confirmed with magnetic resonance imaging. A T4-T5 hemi-dorsal laminectomy was performed to decompress the spinal cord. Histopathological examination was consistent with vertebral angiomatosis. After the surgery, the dog rapidly improved; however, 5 mo later the clinical signs relapsed. Vertebral angiomatosis is a vasoproliferative disorder, rarely reported as a cause of myelopathy in cats. This condition has not previously been reported in dogs. This case report describes the clinical features, the diagnostic findings, and the follow-up of a young dog with vertebral angiomatosis.

Progressive angiomatosis, resembling human skeletal-extraskeletal angiomatosis, arising in multiple digits in two dogs

Two dogs presented with progressive, expansile and invasive lesions on a hind paw. Case 1, a 10-year-old female Shetland sheepdog had diffusive and aggressive-looking lesions on the middle digits of the left hind paw. Radiographic examination showed invasion into and destruction of the underlying bone. A malignant tumour was suspected initially; however, histological features of atypical vascular proliferations without mitotic activity were consistent with progressive angiomatosis. Case 2, an 11-year-old female English springer spaniel presented with similar lesions in the same toes, also involving bone. Progressive angiomatosis was suspected clinically, as tumour cells were not detected by cytology and screening did not detect metastatic disease. Histopathology confirmed the diagnosis. Progressive angiomatosis is an uncommon non-malignant condition which should be considered as a differential diagnosis for radiographically lytic digital lesions.

Successful long-term outcome with radiation and prednisolone following a postoperative feline vertebral angiomatosis relapse

Case summary

A 1-year-old male castrated domestic shorthair cat was presented to the Ontario Veterinary College for a week-long history of lethargy and reluctance to walk. CT and MRI revealed a monostotic T5 compressive vertebral lesion that was excised in surgery via pediculectomy. Histology and advanced imaging were consistent with feline vertebral angiomatosis. The cat relapsed both clinically and on CT 2 months postoperatively and was therefore treated with an intensity-modulated radiation therapy protocol (45 Gy over 18 fractions) and tapering doses of prednisolone. On follow-up CT and MRI at 3 and 6 months post-radiation, the lesion was static and then improved at 19 months post-radiation, with no signs of pain reported.

Relevance and novel information

To our knowledge, this is the first described case of a postoperative relapse of feline vertebral angiomatosis treated with radiation therapy and prednisolone with a successful long-term follow-up.

Spinal epidural arteriovenous fistula in 3 cats

Three young adult cats with intermittent spinal hyperesthesia and paraparesis and diagnosed with spinal epidural arteriovenous fistula are described. In all 3 cases, magnetic resonance imaging (MRI) showed focal dilatation of the veins in the epidural space of the thoracic spinal cord, whereas computed tomography angiography (CTA) showed dilatation and enhancement from the intercostal vein to the azygos vein at the same site in the arterial phase. Dorsal laminectomy and occlusion of the interarcuate branches running across the dorsal aspect of the spinal cord were performed in all 3 cats to decompress the spinal cord, which resulted in a remission of clinical signs and no recurrence during 14 to 40 months of follow‐up after surgery in all cases.

A Review of Proliferative Vascular Disorders of the Central Nervous System of Animals

In disease, blood vessel proliferation has many salient roles including in inflammation, when granulation tissue fills superficial defects, or in the recanalization of an occluded blood vessel. Sometimes angiogenesis goes awry-granulation can be exuberant, and plexiform proliferation of vascular components can contribute to pulmonary hypertension. This review focuses on the diverse manifestations of pathologic vascular overgrowth that occur in the brain, spinal cord, and meninges of animals from birth until old age. Entities discussed include systemic reactive angioendotheliomatosis in which glomeruloid vascular proliferations are encountered in various organs including the central nervous system (CNS). The triad of CNS vascular malformations, hamartomas, and benign vascular proliferations are an especially fraught category in which terminology overlap and the microscopic similarity of various disorders makes diagnostic classification incredibly challenging. Pathologists commonly take refuge in "CNS vascular hamartoma" despite the lack of any unique histopathologic features and we recommend that this diagnostic category be abandoned. Malformative lesions that are often confusing and have similar features; the conditions include arteriovenous malformation, cavernous angioma, venous angioma, and capillary telangiectases. Meningioangiomatosis, a benign meningovascular proliferation with dual components, is a unique entity seen most commonly in young dogs. Last, accepted neoplastic conditions range from lower-grade locally acquired growths like hemangioblastoma (a tumor of mysterious interstitial stromal cells encountered in the setting of abundant capillary vasculature proliferation), the rare hemangioendothelioma, and the highly malignant and invariably multifocal metastatic hemangiosarcoma. Additionally, this review draws on the comparative medical literature for further insights into this problematic topic in pathology.