Gliomatosis cerebri in two dogs

A 3.5 yr old Saint Bernard was evaluated for nonambulatory tetraparesis and cranial nerve dysfunction, and a 7 yr old rottweiler was evaluated for progressive paraparesis. Clinical signs of left-sided vestibular and general proprioceptive ataxia and cranial nerve VII dysfunction in the Saint Bernard suggested a lesion affecting the brain stem. Signs in the rottweiler consisted of general proprioceptive/upper motor neuron paraparesis, suggesting a lesion involving the third thoracic (T3) to third lumbar (L3) spinal cord segments. MRI was normal in the Saint Bernard, but an intra-axial lesion involving the T13-L2 spinal cord segments was observed in the rottweiler. In both dogs, the central nervous system (CNS) contained neoplastic cells with features consistent with gliomatosis cerebri (GC). In the Saint Bernard, neoplastic cells were present in the medulla oblongata and cranial cervical spinal cord. In the rottweiler, neoplastic cells were only present in the spinal cord. Immunohistochemistry disclosed two distinct patterns of CD18, nestin, and vimentin staining. GC is a rarely reported tumor of the CNS. Although GC typically involves the cerebrum, clinical signs in these two dogs reflected caudal brainstem and spinal cord involvement.     

Neurological,imaging and pathological features of a meningeal inflammatory pseudotumour in a Maltese terrier

A five-year eight-month-old Maltese terrier was presented with a 3-week history of progressive paraparesis and pelvic limb ataxia. Neurological examination was consistent with a lesion involving the T3-L3 spinal cord segments. Myelogram and magnetic resonance imaging revealed a spherical, intradural-extramedullary mass lesion at T13/L1. A dorsal laminectomy, durotomy and debulking of the mass were performed. Histopathologic examination revealed a highly cellular tissue, most likely of mesenchymal origin, infiltrated by many lymphocytes, macrophages and neutrophils. The pathological diagnosis of an inflammatory pseudotumour was made. Postsurgical analgesia was achieved with opioids and 2 mg/kg carprofen twice daily for 5 days. When the histopathological diagnosis was made, a tapering course of 1 mg/kg prednisolone twice daily was prescribed, with dose reduction by approximately 50% every 4 to 6 weeks over a 4-month period. Magnetic resonance imaging was repeated at 22, 32 and 85 weeks postsurgery; no signs of regrowth could be detected and the patient recovered with residual mild paraparesis. Inflammatory pseudotumour has not been documented previously at this site in dogs and, although rare, should be considered in the differential diagnosis of a focal mass lesion affecting the spinal cord. Surgical debulking and immunomodulatory therapy can be curative.     

Intramedullary epidermoid cyst in the thoracic spine of a dog

A 5 yr old female spayed mastiff was evaluated for a 3-4 mo history of paraparesis and 3 days of acutely worse paraparesis and incontinence. On magnetic resonance imaging, a spinal cord lesion was present at the ninth thoracic vertebra. The lesion was hyperintense on T2-weighted images (T2-W), and a hyperintense rim was present on T1-weighted postcontrast images. Histologic examination showed a cystic mass lined by squamous epithelial cells. Histopathologic diagnosis was an intramedullary epidermoid spinal cyst. Epidermoid cyst should be a differential diagnosis in young dogs with a myelopathy and an intramedullary spinal cord lesion on magnetic resonance imaging examination.     

IMAGING DIAGNOSIS—SPINAL EPIDURAL HEMANGIOSARCOMA IN A DOG

An 8‐year‐old, male Boxer was examined for an acute onset of ambulatory paraparesis. Neurologic examination was consistent with a T3‐L3 myelopathy. Myelography revealed an extradural spinal cord compression in the region of the T10‐T13 vertebrae. On magnetic resonance (MR) imaging, a well‐defined epidural mass lesion was detected. The mass was mildly hyperintense on T1‐weighted, hyperintense on T2‐weighted and STIR images compared to normal spinal cord and enhanced strongly and homogenously. Postmortem examination confirmed a primary epidural hemangiosarcoma. Findings indicated that the MRI characteristics of spinal epidural hemangiosarcoma may mimic other lesions including meningioma and epidural hemorrhages/hematomas of non‐neoplastic etiology.     

Extradural spinal juxtafacet (synovial) cysts in three dogs

Three dogs were presented for investigation of spinal disease and were diagnosed with extradural spinal juxtafacet cysts of synovial origin. Two dogs that were presented with clinical signs consistent with pain in the lumbosacral region associated with bilateral hindlimb paresis were diagnosed using magnetic resonance imaging. Both cysts were solitary and associated with the L6-7 dorsal articulations; both the dogs had a transitional vertebra in the lumbosacral region. A third dog that was presented with progressive paraparesis localised to T3-L3 spinal cord segments and compression of the spinal cord at T13-L1 was diagnosed using myelography. A solitary multiloculated cyst was found at surgery. Decompressive surgery resulted in resolution of the clinical signs in all three dogs. Immunohistological findings indicated that one to two layers of vimentin-positive cells consistent with synovial origin lined the cysts.     

Thoracolumbar spinal cord compression due to vertebral process degenerative joint disease in a family of Shiloh Shepherd dogs

Five young Shiloh Shepherd Dogs (4 males and 1 female) related by a common sire were studied because of progressive pelvic limb weakness and incoordination. All dogs had a spastic paraparesis and pelvic limb ataxia consistent with an upper motor neuron and general proprioceptive lesion between spinal cord segments T3 and L3. Proliferative lesions involving one or more of the articular processes from the 11th thoracic vertebrae to the 2nd lumbar vertebra were observed on radiographs of the thoracolumbar vertebrae. Dorsal compression of the spinal cord was identified during imaging studies at these sites. Abnormalities of the synovial joints and bony proliferation of the involved articular processes were identified at postmortem examination in 2 dogs. The articular processes and associated vertebral arches protruded into the vertebral canal, indenting the dorsal surface of the spinalcord. Degenerative joint disease (DJD) was identified histologically. A compressive myelopathy was diagnosed in the spinal cord. These dogs were affected by a compressive myelopathy as a consequence of vertebral process DJD that likely has a geneticcomponent. The DJD could have been caused by a primary vertebral malformation or an injury to the processes at a young age causing malarticulation.     

Suspected primary glioblastoma multiforme in the canine spinal cord

An eight‐year‐old mixed‐breed dog was presented with progressive paraparesis. Neurological examination revealed a painful diffuse lesion between spinal cord segments T3 and L3. Magnetic resonance images displayed multi‐focal contrast enhancing spinal cord and meningeal lesions. Cytology of these lesions revealed a malignant tumour prompting euthanasia of the dog. Histopathology confirmed the cytological diagnosis and a final diagnosis of a glioblastoma multiforme was made based on immunohistochemistry.     

Probable lumbar acute non-compressive nucleus pulposus extrusion in a cat with acute onset paraparesis

A spinal cord lesion localised caudal to the L6 spinal segment was diagnosed in a 2-year-old female spayed domestic longhair cat with acute onset paraparesis. Magnetic resonance imaging findings were consistent with an acute, non-compressive nucleus pulposus extrusion of the L5-L6 intervertebral disc. The cat was successfully managed with supportive care, including cage confinement.     

Intraspinal epidermoid cyst in a dog

A 2-year-old female Rottweiler was examined because of progressive gait deficits consistent with transverse myelopathy between the T2 and L3 spinal cord segments. Myelography confirmed an intramedullary spinal cord lesion between T13 and L1, so the dog was euthanatized. At necropsy, an intramedullary epidermoid cyst was confirmed in the T13 and L1 spinal cord segments. The epidermoid cyst probably resulted from a congenital cause.     

Diffuse idiopathic skeletal hyperostosis of the spine in a nine‐year‐old cat

A nine‐year‐old intact female domestic shorthair cat was evaluated for paraparesis, ataxia and severe spinal hyperaesthesia. Neurological examination indicated a T3‐L3 spinal cord segment lesion. Computed tomography of the thoracolumbar and lumbosacral vertebral column was performed. This showed contiguous smooth new bone formation ventral and lateral to the vertebrae extending from the cranial thoracic area to the lumbosacral junction and appearing similar to canine diffuse idiopathic skeletal hyperostosis. There was also marked dorsolateral stenosis of the vertebral canal at the level of T4‐T5 because of degenerative changes of the facet joints. To the authors’ knowledge, this is the first published report of feline diffuse idiopathic skeletal hyperostosis.     

Fecal incontinence associated with epidural spinal hematoma and intervertebral disk extrusion in a dog

CASE DESCRIPTION: A 7-year-old castrated male Great Dane was evaluated because of a 2-month history of fecal incontinence. CLINICAL FINDINGS: On the basis of the presence of paraparesis and apparently normal spinal reflexes, the neurologic signs were localized in the region of the third thoracic to the third lumbar spinal cord segments. On the basis of the findings of magnetic resonance imaging, a presumptive diagnosis of a compressive intervertebral disk extrusion with secondary hemorrhage and epidural hematoma formation was made. TREATMENT AND OUTCOME: A right-sided hemil-aminectomy was performed (centered at the T13-L1 intervertebral space) to further characterize the lesion and decompress the spinal cord. The histopathologic diagnosis was extruded intervertebral disk material with chronic hemorrhage and inflammation. Three weeks after surgery, there was complete resolution of the dog's fecal incontinence and moderate improvements in its hind limb function. CLINICAL RELEVANCE: Thoracolumbar spinal cord injuries can result in upper motor neuron fecal incontinence in ambulatory dogs. Epidural spinal hematomas may develop secondary to intervertebral disk herniations and cause spinal cord compression resulting in neurologic deficits.     

Multiple cartilaginous exostoses in a dog

A case of multiple cartilaginous exostoses (osteochondromatosis) in a 9-month-old Kelpie cross dog is described. This uncommon dyschondroplasia, which resembled multiple cartilaginous exostoses in man, involved the radius, the femur, a metacarpal and metatarsal bone, the phalanges of three extremities, the pelvis, the ribs and cervical, thoracic and coccygeal vertebrae.     

Meningeal sarcoma mimicking a sciatic neuropathy in a dog

A 5-year-old Golden Retriever presented for lameness evaluation and removal of a dynamic compression plate on the left femur exhibited neurologic signs compatible with a left sciatic peripheral neuropathy. Radiographs revealed a healed fracture of the left femur and a slightly narrowed intervertebral disc space with ventral spondylosis at T_12–13. An EMG demonstrated fibrillation potentials and positive sharp waves in the left hind limb muscles innervated by the peroneal nerve. Surgery was performed to remove the bone plate and explore the left sciatic nerve. The proximal 3 cm of the left peroneal nerve was surrounded by thick fibrous connective tissue and its diameter was smaller than the more distal segment. The dog's condition remained static for 4 weeks and then gradually progressed to paraparesis in 2 weeks. A neurologic examination at that time indicated a caudal lumbar spinal cord lesion and a myelogram confirmed an intradural mass at the level of the 4th lumbar vertebra. The dog was destroyed and a necropsy performed. The histologic diagnosis was meningeal sarcoma.     

MYELOPATHY SECONDARY TO AORTOCAVAL FISTULA IN A CAT

A 15-month-old neutered male cat was presented for progressive paraparesis of 3 months' duration and suspected cardiomegaly. Neuroanatomical localization was a T3-L3 myelopathy. On abdominal ultrasound, an anomalous vessel with turbulent blood flow was identified arising from the caudal vena cava. Myelography showed a bilateral ventrolateral extradural spinal cord compression from T12 to L4. Nonselective angiography and contrast-enhanced computed tomography clearly indicated a vascular complex and vena caval aneurysm with an engorged internal vertebral venous plexus. Surgical occlusion of the anomalous vessels was unsuccessful.     

IMAGING DIAGNOSIS—CT MYELOGRAPHY IN A DOG WITH INTRAMEDULLARY INTERVERTEBRAL DISC HERNIATION

A 5‐year‐old Chihuahua was examined for peracute pain and paraparesis. Neuroanatomic localization was consistent with a symmetric T3‐L3 myelopathy. Computed tomography (CT) of the T9‐L5 vertebrae was normal. Myelography disclosed attenuation of the subarachnoid space from T11 to L1, consistent with spinal cord swelling. CT following the myelogram disclosed a focal area of intramedullary iodinated contrast medium at T13‐L1. At surgery, intervertebral disc material was removed from the spinal cord. Based on the findings in this patient, intramedullary disc herniation should be considered a cause for focal intramedullary contrast medium accumulation.     

Paraparesis in a dwarf goat: clarification by means of magnetic resonance imaging

A 4-year old pygmy goat with chronic paraparesis of the hindlimbs was referred to the Ruminant Clinic of the University of Berne. The causative lesion was localized to the thoracolumbar spinal cord after a thorough clinical examination. Because a radiographic examination of the spine had not been diagnostic, magnetic resonance imaging (MRI) was performed. A mass compressing the spinal cord in the region of L2-L5 was detected. The goat was euthanized and autopsied, which allowed for the definitive diagnosis of lymphosarcoma. In addition to the changes in the lumbar area, further neoplastic masses were detected in the region of the thoracic vertebrae, near the thoracic aperture, on the lungs and on the pericardium. However, these processes had not yet caused clinical signs. MRI investigation allowed for the ante mortem diagnosis of an infiltrative mass in the spinal canal of this goat.     

Invasive histiocytic sarcoma of the lumbar spine in a ferret (Mustela putorius furo)

This report describes the history, clinical examination and histopathology of a histiocytic sarcoma in a domestic ferret. Clinical signs were acute paraplegia and dysuria. Physical examination revealed a firm, smooth, touch‐sensitive mass in and around the lumbar vertebral column. Neurologic examination was consistent with a lesion between spinal cord segments T3 and L3. Magnetic resonance images revealed bone lesions of L2 and L3 combined with compression of the spinal cord due to a homogenous, isointense mass that was diagnosed as a malignant round cell tumour and the ferret was euthanased. Histopathology confirmed the diagnosis of an infiltrative histiocytic sarcoma.     

Treatment of thoracolumbar spinal cord compression associated with Histoplasma capsulatum infection in a cat

CASE DESCRIPTION: A 7-year-old domestic shorthair cat with a 2-month history of decreased appetite and weight loss was examined because of paraparesis of 1 week's duration that had progressed to paraplegia 3 days earlier. CLINICAL FINDINGS: Neurologic examination revealed normo- to hyperreflexia and absence of deep pain sensation in the hind limbs and thoracolumbar spinal hyperesthesia. Neuro-anatomically, the lesion was located within the T3 through L3 spinal cord segments. Biochemical analysis and cytologic examination of CSF revealed no abnormalities. Radiography revealed narrowing of the T11-12 intervertebral disk space and intervertebral foramen suggestive of intervertebral disk disease. Myelography revealed an extradural mass centered at the T12-13 intervertebral disk space with extension over the dorsal surfaces of T11-13 and L1 vertebral bodies. TREATMENT AND OUTCOME: A right-sided hemilaminectomy was performed over the T11-12, T12-13, and T13-L1 intervertebral disk spaces, and a space-occupying mass was revealed. Aerobic bacterial culture of samples of the mass yielded growth of a yeast organism after a 10-day incubation period; histologically, Histoplasma capsulatum was identified. Treatment with itraconazole was initiated. Nineteen days after surgery, superficial pain sensation and voluntary motor function were evident in both hind limbs. After approximately 3.5 months, the cat was ambulatory with sling assistance and had regained some ability to urinate voluntarily. CLINICAL RELEVANCE: In cats with myelopathies that have no overt evidence of fungal dissemination, differential diagnoses should include CNS histoplasmosis. Although prognosis associated with fungal infections of the CNS is generally guarded, treatment is warranted and may have a positive outcome.     

CT and MRI imaging diagnosis of epidural idiopathic sterile pyogranulomatous inflammation in a dog spinal canal

A 12-year-old neutered male shih tzu developed progressive pelvic limb paraparesis. Computed tomography showed a radiolucent mass lesion in the spinal canal at the left side of the 11th thoracic vertebra. The mass was not enhanced by intravenous contrast medium injection. It was hyperintense on both T1- and T2-weighted magnetic resonance images. The signal intensity of the mass was decreased with a fat suppression technique, indicating a fatty origin. After removal of the mass via T11-T12 hemilaminectomy, chronic panniculitis was confirmed by histopathological examination. This case demonstrates the utility of computed tomography and magnetic resonance imaging for the diagnosis of spinal canal pyogranulomatous inflammation.     

MALIGNANT TRANSFORMATION OF SOLITARY SPINAL OSTEOCHONDROMA IN TWO MATURE DOGS

Canine osteochondroma is an uncommon bony tumor that arises in skeletally immature animals. Consequently, clinical signs typically occur in young dogs as a result of impingement of normal structures by the tumor. Radiographically, osteochondromas are benign in appearance. They are well circumscribed and cause no bony lysis nor periosteal proliferation. Osteochondromas may occur in two forms; solitary or multiple. Although histology and biologic behavior are identical, when in the multiple form the condition has been termed multiple cartilaginous exostoses. Malignant transformation of multiple cartilaginous exostoses has been reported in three mature dogs. We report two dogs with malignant transformation of solitary spinal osteochondromas. Both underwent transformation to osteosarcoma. Despite the benign radiographic appearance of osteochondromas and multiple cartilaginous exostoses, clinical signs should alert the clinician to the possibility of malignant transformation.