Anaplastic ependymoma in the cervical spinal cord of a maltese dog

An 8-year and 6-month-old female Maltese dog showed a stoop with rigidity of her cervix and back. Neurologic examination showed loss of proprioception, and deficiency of pain response. Postmortem examination revealed the neoplastic mass replacing the central area in the cervical spinal cord at the level from 4th to 5th segments. Histologically, the mass was composed of neoplastic ependymal cells. The neoplastic cells showed marked atypism, and occasionally formed ependymal rosettes. Based on the morphologic features, the tumor was diagnosed as anaplastic ependymoma. Immunohistochemistry showed that the neoplastic cells were negative for glial fibrillary acid protein, and slightly positive for vimentin and cytokeratin.     

Surgical treatment of an intramedullary spinal cord hamartoma in a dog

A 9-year-old spayed female Golden Retriever was examined because of progressive hind limb lameness. Magnetic resonance imaging of the thoracic and lumbar portions of the vertebral column revealed a focal, contrast-enhancing, intramedullary spinal cord mass. The history, signalment, and magnetic resonance findings were suggestive of spinal cord neoplasia. A hemilaminectomy, durotomy, and longitudinal myelotomy were performed, and a 1 X 1-cm mass that contained numerous blood vessels was removed with blunt dissection. Results of histologic examination and immunohistochemical staining of the mass suggested that it was a hamartoma. The dog improved after surgery, with no evidence of a recurrence of clinical signs 14 months after surgery. Vascular malformations of the CNS in dogs include hamartomas, hemangiomas, angiomas, hemangioblastomas, meningocerebral hemangiomatosis, and arteriovenous malformations. A hamartoma is a non-neoplastic overgrowth of cells or an improper proportion of cells that are normally in the involved tissue. Although magnetic resonance imaging may be helpful in determining the extent of the lesion in dogs with vascular malforrmations, it cannot be used to distinguish neoplastic from non-neoplastic formations. Excision may result in a good outcome for dogs with an intramedullary spinal cord hamartoma.     

犬脊髓损伤的诊疗报告

脊髓损伤是畜体遭受机械外力作用后引起的脊髓伤害,当脊髓受到一定程度的伤害后,其中枢神经系统中的传导神经受到阻滞,引起畜体感觉和运动机能障碍,从而可能造成截瘫的一种疾病.     

Surgical removal of an intramedullary spinal cord foreign body granuloma in a dog

A 2-year-old, spayed female, mixed-breed dog was presented for evaluation of a progressive asymmetric tetraparesis and cranial nerve deficits with a 3-week duration. Computed tomography showed a contrast-enhancing lesion along the left side of the junction of the medulla and the cervical spinal cord. An exploratory surgery determined the presence of an intramedullary lesion of the first cervical spinal cord segment. The mass was removed through a dorsal midline myelotomy. Microscopic examination identified a foreign body granuloma that contained a dense, anisotropic outer wall, supporting the conclusion that the foreign body was of plant origin. The dog recovered to a more improved ambulatory status than prior to surgery.     

Cervical spinal cord astrocytoma in a dog

An astrocytoma of the cervical spinal cord was diagnosed in a 3-year-old Siberian Husky. The dog had an 8-week history of progressive neurologic deficits that finally resulted in nonambulatory tetraparesis. Neurologic examination, CSF analysis, myelography, exploratory laminectomy and histopathologic examination were performed. Intramedullary spinal cord tumors such as astrocytomas are rare, and this case illustrates the manner in which spinal cord tumors may be confused with other nervous system diseases, both from a clinical and clinicopathologic standpoint.     

Teratoma in the cervical spinal cord of a dog

An 11-year-old, spayed female giant schnauzer was presented for evaluation of chronic, progressive tetraparesis. Diagnostic imaging was consistent with intervertebral disk protrusion, and surgical decompression and stabilization were performed. Postoperatively the dog did not improve, and further imaging suggested an intramedullary mass at the level of the sixth cervical vertebra. The dog was euthanized 7 days after surgery, and a teratoma was found postmortem.     

Oligodendroglioma in the cervical spinal cord of a dog

A 7-year-old male castrated Yorkshire Terrier dog developed slowly progressive neurologic disturbances consisting of difficulties in moving the neck, lack of proprioception, and tetraparesis 4 months prior its death. Neurologic examination, computer tomography, and myelography resulted in the tentative diagnosis of intramedullary cervicothoracic spinal cord lesion. At necropsy, an intramedullary cervical spinal cord mass between C5 and C6 was noticed. Histologically, cells of this well-demarcated, nonencapsulated neoplasm were arranged in sheaths or cords separated by a fine fibrovascular stroma. The polygonal to round tumor cells were characterized by moderate pale, basophilic, and vacuolar cytoplasm and round to slightly oval, centrally located nuclei with fine-stippled heterochromatin, a single nucleolus, and a very low mitotic activity. Tumor cells lacked glial fibrillary acidic protein, vimentin, factor VIII-related, and cytokeratin antigen expression. Histologic and immunohistochemical findings led to the diagnosis of a cervical spinal cord oligodendroglioma.     

Extraventricular neurocytoma of the spinal cord in a dog

Central neurocytoma is a rare, prognostically favorable neuronal tumor of the human central nervous system, typically located intraventricularly near the foramen of Monro. Extraventricular cerebral neurocytomas and spinal tumors have also been reported. To date, however, neurocytomas have not been documented in domestic animal species. In this report, we describe a spinal cord tumor in a dog. The microscopic examination revealed tumor cells forming loosely packed clusters in some areas and palisades in other areas. In addition, they showed fine fibrillary neuropil-like areas of different sizes, sometimes resembling the "rosettes" of pineocytomas, as well as ependymoma-like perivascular pseudorosettes. The tumor cells had scant eosinophilic cytoplasm, with perinuclear halos, closely resembling the appearance of oligodendroglioma. Immunohistochemical staining showed expression of synaptophysin and neuron-specific enolase by tumor cells and pronounced in fibrillary areas. On the basis of histomorphology and immunohistochemical reactivity, the present tumor was diagnosed as extraventricular neurocytoma.     

Malignant glioma of the spinal cord in a dog

The history, clinical signs, diagnosis and post-mortem findings of a malignant glioma of the spinal cord of a 5-year-old female Borzoi are reported. A discrepancy between the localization of the cord lesion by neurological examination and myelography is described. A myelogram showed a filling defect of the subarachnoid space caudal to the cord lesion. As the site for surgical exploration was based on the myelographic findings the cord tumour was not exposed during surgery. Autopsy confirmed a malignant glioma in the area of the cord suggested by neurological examination.     

Ventricular ependymoma in a German Shepherd dog

Using magnetic resonance imaging (MRI) together with clinical, pathomorphological and immunohistological methods, a ependymoma is described in a 9-year-old German Shepherd dog, which presented with behavioural and oculocephalic responses and generalised ataxia. The ependymoma, 9 x 6 x 5mm in size, was localised intra-axially in the right interventricular foramen and hydrocephalus was observed by MRI. Microscopically, the tumour was composed of pseudorosettes, and immunohistochemical examination revealed vimentin and glial fibrillary acidic protein immunoreactivity in the neoplastic cells.     

Surgical treatment of gastric leiomyoma in a dog

A 12-year-old entire male Maltese terrier was presented with a 1 month history of vomiting and haematemesis. Microcytic hypochromic anaemia was detected. Abdominal radiography, ultrasonography and gastric endoscopy identified a discrete intramural mass in the pyloric antrum. An ulcerated leiomyoma was removed by a partial-thickness intraluminal resection of the gastric wall. The dog recovered well and is free from clinical signs 20 months after surgery.     

Intramedullary spinal cord metastasis of a primary lung tumour in a dog

A dog was presented with signs of subacute, progressive myelopathy. A tentative diagnosis of a diffuse intramedullary spinal cord mass was made using contrast radiography (myelography). At autopsy a solitary, large bronchoalveolar carcinoma was detected in a lung lobe. Histological examination of the cranial thoracic spinal cord revealed a tumour which was similar, but not identical, to the lung tumour. Immunohistochemistry helped to confirm that the spinal lesion was a metastasis of the lung tumour.     

Posterior mediastinal paraganglioma involving the spinal cord of a dog

A posterior mediastinal paraganglioma is described in a five-year-old female collie showing paralysis of the hindlimbs. The mass was observed radiographically and a myelogram confirmed a spinal cord compression at the thoracic level. Histological examination of the mass diagnosed a paraganglioma which was confirmed by histochemical and immunohistochemical studies. This is compared with paraganglioma found in man.     

Surgical treatment of a duplicated and ectopic ureter in a dog

An eight‐month old female bull mastiff was referred for evaluation of urinary incontinence. Contrast‐enhanced computed tomography identified complete duplication of the left ureter with ectopic insertion of the duplicate ureter into the proximal urethra. Ureteroneocystostomy was performed, which improved but did not resolve urinary continence. To the authors’ knowledge, this report details only the second reported case of duplicated ectopic ureter in the dog and the first documenting surgical reimplantation; thus, double‐system ureteral ectopia should be considered as a possible differential diagnosis for urinary incontinence.     

Surgical treatment of a congenital bronchoesophageal fistula in a dog

A 1-year-old male Cairn Terrier was evaluated for chronic coughing that was aggravated by eating or drinking. Radiography revealed an esophageal diverticulum, regional megaesophagus, and focal interstitial densities in the right caudal and middle lung lobes. Using fluoroscopy and contrast radiography, contrast material was seen to accumulate in the diverticulum and to reflux into the right middle, caudal, and accessory bronchi. Radiographic diagnosis was bronchoesophageal fistula. Via right eighth intercostal space thoracotomy, the abnormal connection between esophagus and caudal lobe of the right lung was identified, the lobe was resected, and the esophagus was closed. Histologic examination of the connecting tissue revealed a lining of stratified epithelium, with the superficial layer being predominantly ciliated columnar epithelium. Several findings led to the conclusion that the fistula was a congenital lesion, arising from aberrant formation of the respiratory tract from the embryologic digestive tract. Histologic examination revealed smooth muscle and lack of inflammation in tissue surrounding the fistula, which are criteria for identifying congenital bronchoesophageal fistula in human patients. The dog was young and did not have a history of esophageal foreign bodies. Postoperative complications were not encountered, and 9 months later, the dog was reported to be eating dry dog food without coughing. Congenital and acquired bronchoesophageal fistulas in dogs are reported infrequently. Furthermore, 2 of 12 previously reported bronchoesophageal fistulas in dogs, one of which was considered congenital, developed in Cairn Terriers.     

Malignant mediastinal extra-adrenal paraganglioma with spinal cord invasion in a dog.

A 1.5-year-old castrated, male, mixed-breed dog was evaluated because of a 2-week history of lethargy, stiffness, and progressive paraparesis. Spinal radiographs, myelography, and computed tomography of the region showed a locally invasive mass involving the thoracic wall. Upon necropsy, an encapsulated, fluctuant mass was noted attached to the right dorsal body wall in the region of the fifth to seventh thoracic vertebra. Churukian-Schenk staining revealed positive granules within the neoplastic cell cytoplasm and immunohistochemistry was positive for expression for cytoplasmic neuron-specific enolase and synaptophysin. Chromogranin A and S100 expression were found to be negative. Immunohistochemistry and silver staining did not allow further differentiation of the tumor, and the diagnosis remains consistent with either a chromaffin paraganglioma or a nonchromaffin paraganglioma (chemodectoma) with some production of catecholamines. Extra-adrenal paragangliomas are rare neoplasms in dogs but should be considered as a possible differential diagnosis for a primary paraspinal thoracic mass.     

Intramedullary spinal cord damage associated with intervertebral disk material in a dog

Intervertebral disk extrusions into the spinal cord are rarely reported in veterinary medicine, and only necropsy findings are described in previous reports. It is hypothesized that a disk lesion results in forceful injection of disk material into the spinal cord. In the 3-year-old Miniature Doberman Pinscher of our report, acute clinical signs and results of magnetic resonance imaging were consistent with this disease and helped determine the extent and character of the lesions. Alteration in the appearance of the nucleus pulposus was important in determining that intervertebral disk disease may have been present in this dog. However, a definitive diagnosis of intramedullary disk extrusion can be made only via histologic examination of a biopsy specimen or at necropsy. The dog improved substantially after surgical decompression of the spinal cord, and histologic findings in a biopsy specimen of material found within the spinal cord were consistent with mature degenerate intervertebral disk material.