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Extradural neoplasms are the most common spinal tumors in small animals. A bilobed appearance of ventral extradural spinal lesions ("gullwing sign") on MRI has been described with various conditions. The objective of this retrospective study was to determine if a "gullwing sign" is more common with certain types of extradural tumors. MRI studies of dogs and cats with extradural spinal neoplasms were reviewed for the presence of a "gullwing sign". Statistical analysis was performed to evaluate a possible relationship between tumor class and the presence of a "gullwing sign". Sixty-six cases were included (5 epithelial, 31 mesenchymal, 4 neuroendocrine, and 26 round cell tumors). A "gullwing sign" was identified in 12 of 66 cases (18.2%) and was significantly more common with round cell neoplasia than other tumor types (P < .001; OR = 28.6, 95% CI [3.4, 241.1]). This information may aid radiologists in prioritizing differential diagnoses for extradural tumors in small animals., (© 2024 American College of Veterinary Radiology.)

A 3-year-old Pygmy Wether was presented for chronic hindlimb paralysis. A neurological exam revealed nonambulatory paraplegia with absent deep pain nociception, lack of hindlimb withdrawal reflexes, and paraspinal pain on palpation with T3 to L3 neurolocalization. MRI of the lumbar spine revealed an extensive, dorsal to dorsolateral, severely compressive, heterogeneously contrast-enhancing extradural lesion of the lumbar spine with intervertebral foraminal extension into the surrounding paraspinal musculature. Vertebral bone marrow involvement was also noted in the L5 and L6 vertebrae. A diagnosis of lymphoma was obtained after cytological sampling. This is the first case report describing specific MRI findings (signal characteristics, enhancement pattern, and perilesional changes) in a goat with paraspinal lymphoma., (© 2024 American College of Veterinary Radiology.)

A 7-year-old spayed female ferret was presented to the Veterinary Teaching Hospital at the Western College of Veterinary Medicine for a slow-growing mass involving the base of the tail. Radiographs revealed a large, irregularly marginated mineralized mass centered on the fifth to seventh caudal vertebrae with osteolysis of the affected caudal vertebrae. A partial caudectomy was performed, and histopathology was consistent with a chordoma. This is the first case report describing the radiographic appearance of a chordoma in the proximal tail and only the second report to describe radiographic findings in a ferret., (© 2022 American College of Veterinary Radiology.)

Background: Reports of osteoblastic tumours are limited to a few case reports in veterinary medicine. Osteoblastoma-like osteosarcoma has been accepted by the World Health Organization as an intermediate form between an osteosarcoma and osteoblastoma. This type of tumour indicates an osteosarcoma, that may resemble osteoblastoma clinically, histologically, and radiologically and have the capability for metastasis. Osteoblastoma-like osteosarcoma has not been described in veterinary medicine so far., Case Presentation: An eight-year old cat was presented due to progressive ataxia and paraparesis of the pelvic limbs. Imaging confirmed a well-defined, extradural mass originating from the spinous process of the second thoracic vertebra (T2) leading to severe compression of the spinal cord. Decompressive cytoreduction was achieved by removal of the mass after dorsal laminectomy of T1. After recovering from an acute worsening 3.5 weeks after surgery, the cat had an improved neurological status and the dorsal compression was resolved at follow-up 8 months later. A focal contrast enhancing lesion was still evident at the base of T2 spinous process and lung metastasis was additionally suspected. Based on histopathological, radiographic, and clinical features, an "osteoblastoma-like osteosarcoma" was suspected., Conclusions: To the best of our knowledge, this is the first description of this tumour in veterinary medicine. In addition, this case report highlights the difficulty in the diagnosis and definition of osseous neoplasia in cats and provides a literature review.

The naked mole-rat (NMR; Heterocephalus glaber )-a small, eusocial, subterranean rodent native to East Africa-is distinguished by its capability to live long and resist changes associated with the aging process. Notably, a growing amount of research has been dedicated to NMRs' multifactorial capacity to resist cancer. Since 2016, however, zoos have begun to document various neoplasms in a handful of individuals. We present herein radiographic, gross anatomic, and histopathologic features of a case of a sacral chordoma in a geriatric female. Chordomas originate in notochordal remnants. These spinal tumors are most commonly seen in ferrets; chordomas are rare in humans, can be difficult to treat, and need wide surgical margins.

A 6 mo old male castrated bloodhound-Rhodesian ridgeback mix (case 1) presented for a mass suspected to be a dermoid sinus in the thoracolumbar region, and a 2.5 yr old male castrated Rhodesian ridgeback (case 2) presented for a mass suspected to be a dorsal cervical dermoid sinus. Both dogs underwent single-phase contrast computed tomography (CT) to characterize the extent of the dermoid sinus prior to surgical excision. Soft tissue and bony abnormalities of the vertebral spine associated with the dermoid sinuses were confirmed in both dogs prior to surgery, demonstrating communication with the dura of the spinal cord. Surgical exploration and excision of the dermoid sinus was performed in each dog, including partial laminectomy. Both cases had resolution of the sinus and an uncomplicated recovery. These cases show that single-phase contrast CT was accurate in characterizing the extent of the dermoid sinus without adjunctive tests or more invasive diagnostics. Single-phase contrast CT should be considered as a preoperative method to characterize the extent of dermoid sinuses, avoiding the risks associated with myelography or fistulography and the expense of MRI. This is also the first report of a dermoid sinus in the thoracolumbar region and the first in a bloodhound and Rhodesian ridgeback mix.

Primary and metastatic vertebral osteosarcoma (OSA) in the dog carries an overall guarded prognosis. Previously reported definitive treatments in dogs with vertebral OSA have included surgery, radiotherapy, chemotherapy or a combination of those therapies. This retrospective study was completed to determine patterns of failure, duration of local control and survival time in dogs with vertebral OSA treated with stereotactic radiation therapy (SRT). Nine dogs were treated with SRT for vertebral OSA. Protocols ranged from 1 to 5 fractions with total prescription ranging from 13.5 to 36 Gy. Six dogs had primary lesions and 3 had metastatic lesions. Neurologic score improved in 4 patients, remained the same in 4 and worsened in 1. Five of the 6 dogs that presented with assessable spinal pain had reported improvement in pain. Overall median survival time was 139 days and median duration of pain control was 77 days. There was not a statistically significant survival difference between dogs presenting with primary or metastatic disease, or dogs that had improvement in neurologic score following SRT. The data suggests similar survival times to the previously reported definitive treatments in dogs with vertebral OSA and displays continued difficulty in controlling this tumour. The dose limiting structure is the late responding spinal cord, but many of the patients herein died prior to the expected time to development of late radiation side effects., (© 2017 John Wiley & Sons Ltd.)

An 8-year-old neutered male Toy Poodle was presented with chronic, progressive tetraparesis, and possible seizures. Magnetic resonance images demonstrated an extensive, T1 and T2 hyperintense contrast enhancing mass in the cervical spinal cord. Three nodules were present on the surface of the thalamus, with enhancement most evident on delayed images. A diagnosis of high-grade oligodendroglioma was confirmed with postmortem histopathology and immunohistochemical labeling. Oligodendroglioma should be considered as a differential for T1 hyperintense intraaxial or intramedullary lesions with contrast enhancement. If enhancement is not visualized on postcontrast images, delayed images may be beneficial., (© 2016 American College of Veterinary Radiology.)

A 7-year-old cat was referred with pelvic limb ataxia. Radiography and CT revealed bone resorption of the L1 vertebral arch, and myelography identified a compressive extradural lesion. The mass was surgically removed and histopathologically diagnosed as giant cell osteosarcoma. Three years later, the recurrent tumor resection and vertebral fixation were performed. Six months later, vertebrectomy was performed to radically excise the recurrent mass and a titanium spinal cage was placed. The cat is alive approximately 5 years after the first surgery. This case report describes vertebrectomy and vertebral body replacement as a radical treatment for feline vertebral osteosarcoma.

A 7-month-old intact male Otterhound was presented for diagnosis of progressive hindlimb paresis. The neurological examination revealed a severe ambulatory paraparesis localised to the left-sided region of the lower motor neuron (L4-S1). Magnetic resonance imaging was suggestive for an intradural-extramedullary neoplasia at the fifth lumbar vertebra. Surgical exploration demonstrated an intradural-extramedullary mass, which partially invaded the spinal cord. The mass was removed with the exception of the intramedullar part, and the diagnosis of a nephroblastoma was made histopathologically. Following radiation therapy, the dog fully recovered and displayed no signs of neurological dysfunction 9 months after surgery.

Published information regarding canine vertebral column mast cell tumors (MCTs) is limited. The objectives of this study were to report clinical and advanced imaging findings for a group of dogs with confirmed spinal MCT. Inclusion criteria for this retrospective case series were dogs with spinal magnetic resonance imaging (MRI) or computed tomography (CT) scans and a histological diagnosis of spinal MCT. Clinical, imaging, treatment, and outcome data were recorded. Four dogs met inclusion criteria. One dog had primary spinal MCT and three dogs had metastatic spinal MCT. All four dogs presented for paraspinal hyperesthesia and subacute progressive or acute myelopathy. All CT and MRI lesions were extradural. Two cases exhibited distinct masses in the epidural space. In one case, an epidural tumor invaded from the paravertebral musculature. One case exhibited polyostotic lesions indistinguishable from multiple myeloma by MRI. One dog with a primary epidural low-grade MCT remains clinically normal 4 years postoperatively, following adjunctive lomustine. An epidural high-grade MCT, metastatic from a cutaneous tumor, recurred within 2 months of surgery despite adjunctive vinblastine. Two high-grade cases with concurrent visceral involvement were euthanized immediately after imaging. In dogs, MCT should be considered as a differential diagnosis for a progressive painful myelopathy and CT or MRI evidence of an extradural spinal lesion (epidural, paravertebral, or polyostotic). While more often associated with cutaneous or disseminated disease, MCT may also occur as a primary tumor of the epidural space in dogs., (© 2016 American College of Veterinary Radiology.)

A vertebral mass in a dog with an acute onset paraparesis was identified by magnetic resonance imaging. A poorly differentiated hemangiosarcoma was diagnosed by histopathology and immunohistochemistry. Endothelial nitric oxide synthase could be a new differential marker for poorly differentiated hemangiosarcoma in dogs. Immunohistochemical detection of p53 phosphorylated at Serine 392 , p53, CD117, and CD44 suggest targets for design of therapeutic strategies.

A pubectomy was carried out to relieve obstruction of the pelvic canal in a 6-year-old dog diagnosed with sacral osteosarcoma. Two days after surgery, the dog was ambulatory with normal urination and defecation. Pubectomy is a viable option to relieve clinical signs in patients with pelvic canal obstruction due to a non-resectable tumor.

A 9-year-old, neutered female Maine Coon cat with a 6-week history of progressive ataxia was diagnosed with a cervical vertebral body mass using magnetic resonance imaging. The mass displaced and compressed the cervical spinal cord. The cat was humanely destroyed and necropsy examination confirmed a mass within the second cervical vertebral body. Microscopically, the mass was composed of large, clear, vacuolated ('physaliferous') cells. Immunohistochemically, the neoplastic cells expressed both cytokeratin and vimentin and the final diagnosis was a cervical, vertebral body chordoma. This is only the third report of a chordoma in this species and the first in this location. Chordoma should be considered as a potential differential diagnosis for tumours arising from the cervical vertebrae in the cat., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

An adult Canada goose ( Branta canadensis ) was presented unable to walk. On physical examination, conscious proprioception was absent in both legs, and motor function was decreased. The bird did not improve with supportive care and was euthanatized and submitted for postmortem examination. Sagittal sectioning of the spine revealed an intradural growth causing segmental deformity of the lumbosacral spinal cord. The growth was diagnosed as an infiltrative spinal lipoma. Infiltrative lipomas are locally invasive, benign tumors that can be found in any host tissue. They have been documented in small and exotic companion animals, including birds; however, this is the first report of an infiltrative lipoma in the spinal canal of a bird or free-living wild animal.

A 4-year-old, male neutered domestic ferret (Mustela putorius furo) was evaluated for a mass in the left cervical region. The owner elected humane euthanasia, and an autopsy was performed, revealing a neoplasm with infiltration into the left cranial articular fovea of the atlas and cervical vertebrae, with regional compression of the spinal cord. Histologic evaluation was consistent with cervical chordoma. At autopsy, a left cranial lung lobe nodule was observed. Additional sectioning and histologic evaluation revealed multiple foci of metastatic chordoma at this site. A small focus of micrometastasis was also detected in a section from the right lung lobes. Chordoma is the most common musculoskeletal neoplasm of ferrets, arising from remnant fetal notochord. To our knowledge, pulmonary chordoma metastasis has not been previously reported in the ferret. This case demonstrates the potential for visceral metastasis of chordoma in the ferret, as has been reported in other species., (© 2015 The Author(s).)

The T2*-weighted gradient recalled echo sequence is a sensitive means to detect blood degradation products. While not a routine sequence in magnetic resonance imaging of the spine in small animals, it can provide additional valuable information in select cases. The goal of this retrospective, cross-sectional study was to describe findings when acquiring this sequence during magnetic resonance imaging examination of the spine in small animals. The University of Tennessee's veterinary radiology database was searched for dogs and cats that underwent magnetic resonance imaging for suspect spinal disease in which a T2*-weighted gradient recalled echo sequence was acquired and susceptibility artifact was identified. The following information was recorded: signalment, clinical signs, location and appearance of susceptibility artifact, and final diagnosis. Thirty-nine cases were included in the study. Extradural susceptibility artifacts were observed in cases of intervertebral disc herniation with or without associated hemorrhage (n = 28), extradural hemorrhage associated with spinal trauma (n = 2), hemophilia (n = 1), and in a cystic extradural mass (n = 1). Remaining lesions displaying susceptibility artifact were intramedullary and included presumptive acute noncompressive nucleus pulposus extrusion (n = 2), hematoma (n = 1), hemangiosarcoma metastasis (n = 1), intramedullary disc extrusion (n = 1), presumptive meningomyelitis (n = 1), and a mass of undetermined etiology (n = 1). Inclusion of a T2*-weighted gradient recalled echo sequence may be helpful in spinal magnetic resonance imaging when standard imaging sequences are ambiguous or intramedullary lesions are observed., (© 2015 American College of Veterinary Radiology.)

A 19-year-old female Bengal tiger (Panthera tigris tigris) was presented with hind limb weakness, ataxia and respiratory distress. Computed tomography revealed a mass between the left side of the T7 vertebra and the base of the left 7th rib. The tiger then died, and necropsy was performed. Grossly, the vertebral mass was 6 × 5.7 × 3 cm, and invaded the adjacent vertebral bone and compressed the T7 spinal cord. Histologically, the mass was composed of large, clear, vacuolated and polygonal cells with osteochondral matrix. Cellular and nuclear atypia were moderate. The vacuolated cells stained positively for cytokeratin and vimentin and negatively for S-100. Based on these findings, the present case was diagnosed as a vertebral chordoma; the first report in a tiger.

Chordomas are uncommon neoplasms arising from notochord remnants, most commonly occurring in the axial skeleton. Extraskeletal soft tissue chordomas are rare primary tumors, and primary alimentary tract chordomas have not been reported. Herein we report 24 cases of spontaneous primary intestinal chordomas in zebrafish, as well as 9 spontaneous vertebral chordomas. Both intestinal and vertebral tumors showed invasive behavior, although more commonly in the latter. In all cases of primary intestinal chordomas, there was no axial or peripheral skeletal or other nonvisceral involvement. Although uncommon, intestinal chordomas represent a unique background lesion in aged zebrafish., (© The Author(s) 2014.)

A 10-year-old spayed female chinchilla feline presented with gradually progressive tetraparesis and cervical pain that had begun 1 month before the onset of a 4-day tetraplegic episode. Magnetic resonance imaging revealed a large elliptical intramedullary mass at the fourth cervical vertebrae. The mass was removed surgically and diagnosed as an anaplastic astrocytoma. No neurological abnormalities were observed 3 weeks postsurgery. Magnetic resonance at 3.5 year follow-up revealed neither mass regrowth nor recurrence of signs.

The case report describes a narrowing of the spinal canal in the lumbar and sacroiliac regions with entailing acute recumbency in a nearterm 17-year-old Welsh B Pony mare. The reason for recumbency was metastases of a malignant melanoma in the spinal canal of the lumbo-sacral region, where the tumour had invaded the dura mater and applied severe pression on the spinal cord over a length of 10 cm. Clinical findings, laboratory diagnostics, pathological-anatomical and histopathological findings are presented.

Primary bone tumors are only occasionally reported in avian species. This paper presents the cases of an osteosarcoma in a 6-yr-old free-range chicken and a chondrosarcoma in a 3-yr-old barred Plymouth Rock chicken. The well-differentiated, moderately productive osteoblastic osteosarcoma arose from the synsacral vertebrae and had metastasized to the liver. The chondrosarcoma was well differentiated and firmly attached to the left side of the keel. There was no evidence of metastasis.

An 18-month-old, female, spayed domestic ferret (Mustela putorius furo) was presented for progressive hind limb paresis of 1 week duration. The ferret was mentally appropriate but cachexic and ataxic with neurological deficits, which localized the lesion to the lumbosacral region. A depression in the lumbosacral spine was associated with discomfort on palpation. Results of whole body radiographs were consistent with an abnormal angle between vertebrae L6 and S1, which resulted in hyperflexion of the spine. The ferret was euthanized, and histopathological examination revealed an intramedullary lumbosacral teratoma effacing much of the spine in the region of the mass.

A ten-year-old male standard dachshund was presented with a history of neck pain and progressive gait disturbances. Following a neurological examination and diagnostic imaging, including CT, a neoplastic lesion involving the third and fourth cervical vertebrae was suspected. The lesion included an extradural mass on the right side of the spinal canal causing a local compression of the cervical cord. Surgery, using a modified dorsal laminectomy procedure, was performed in order to decompress the cervical spinal cord. Histopathological examination of the extradural mass indicated that the tumour was a chondroid chordoma. Following discharge, the quality of life for the dog was very good for a sustained period, but clinical signs recurred at 22 months. The dog was euthanased 25 months post-surgery. On post-mortem examination, a regrowth of neoplastic tissue was found to have infiltrated the bone and spinal cord at C3-C4. This is the first report to show that palliative surgery can offer successful long-lasting treatment of chondroid chordoma of the cervical spine in the dog.

Magnetic resonance (MR) imaging and histopathology were used to diagnose an articular process synovial myxoma in a dog. On MR images, the tumor was characterized by distortion of the left L1-L2 articular process, widening of the articular process joint, and the presence of a mass contiguous with the synovium of the articular process that displaced the spinal cord. The tumor was T2-hyperintense, T1-hypointense, relative to muscle, and had mild contrast enhancement. The MR features of articular process synovial myxoma may be distinct from other diseases of the articular process joint., (© 2011 Veterinary Radiology & Ultrasound.)

Tumors arising from or involving the spinal cord are important considerations in animals presented for pain and limb dysfunction. Clinical signs of spinal cord dysfunction, however, are not pathognomic for neoplastic disease in most instances. Advanced magnetic resonance imaging (MRI) often accurately identifies the location and extent of abnormalities. Although some spinal neoplasms have a characteristic appearance with MRI, in other instances the abnormalities may not be readily discernable as neoplastic. Histologic diagnosis, therefore, is imperative to provide information regarding potential treatment modalities and prognosis. Histologic diagnosis is most commonly performed following surgical biopsy and is often performed in combination with surgical removal., (Copyright 2010 Elsevier Inc. All rights reserved.)

At necropsy, an 11-year-old Japanese Black cow with anemia, leukocytopenia, and progressive hind limb ataxia had marked diffuse splenomegaly and multiple masses in the thoracic vertebrae. Histologically, neoplastic erythrophagocytic histiocytes were in the splenic red pulp, vertebral masses, and blood vessels of the liver and lungs. The spinal cord was compressed by the vertebral masses. Clinicopathological, macroscopic, and histologic findings were consistent with hemophagocytic histiocytic sarcoma. Vertebral involvement with spinal cord compression and resultant hind limb ataxia is an unusual presentation for this tumor, which has been described mainly in dogs and cats.

An 8-year-old female Persian cat with a gait disorder was brought to our hospital. Pelvic limb mobility had gradually reduced over the preceding 3 months, then rapidly deteriorated 2 weeks before consultation. Signs also occurred in the thoracic limbs. With a tentative diagnosis of neural disease, magnetic resonance imaging and computed tomography were performed. T1-weighted imaging showed isointensity in the seventh cervical vertebra, while T2-weighted imaging revealed hypointensity. Contrast-enhanced T1-weighted imaging revealed a uniformly enhancing mass. Extirpation of the mass relieved the clinical signs, leading to disappearance of the neurological signs. The histopathological examination suggested osteosarcoma.

The clinical, advanced imaging and surgical features of a case of canine extradural mast cell tumour are presented. This rare location has only been reported once before as a primary lesion, although the present case may be a metastatic lesion. Given the frequent occurrence and treatment of cutaneous mast cell tumours in dogs, the finding of spinal metastasis is an important reminder to consider metastatic neoplasia in cases of previously treated cancers presenting with spinal pain.

Spinal lymphoma and concurrent pulmonary filariasis are reported in a pet rabbit. The rabbit presented for pelvic limb paralysis resulting from extradural spinal lymphoma, presumably rising from the body of the sixth lumbar vertebra. The neoplasm was subsequently immunophenotyped as a B-cell lymphoma. Pulmonary filariasis was an incidental finding at necropsy.

A 5-year-old female spayed domestic shorthair cat was presented for evaluation of tetraparesis. The neurologic lesion was localized to the cervical spinal segment (C1-C6). A left axillary mass was identified, and the results of fine needle aspiration cytology indicated malignant round cell neoplasia of possible histiocytic origin. The cells were large, had marked anisocytosis and anisokaryosis, occasional bi- and multinucleation, and cytoplasmic vacuolation. Euthanasia was performed due to the poor prognosis associated with severe, progressive neurologic signs and a malignant neoplasm. Postmortem examination revealed spinal cord compression and an extradural mass at the C1-C2 spinal segment, with neoplastic cells in the adjacent vertebral bodies, surrounding skeletal muscle, left axillary lymph node, and bone marrow from the right femur. The initial histologic diagnosis was anaplastic sarcoma, but immunohistochemical results indicated the cells were CD20+ and CD45R+ and CD3-, compatible with a diagnosis of B-cell lymphoma. CD79a staining was nonspecific and uninterpretable. Weak to moderate CD18 positivity and E-cadherin positivity were also observed. Clonality of the B-cell population could not be demonstrated using PCR testing for antigen receptor gene rearrangement. To the authors' knowledge, this is the first reported case of a feline spinal anaplastic B-cell lymphoma exhibiting bi- and multinucleated cells. The prognostic significance of this cell morphology and immunophenotype is unknown.

An 11-year-old male chinchilla was presented for investigation of progressive weight loss, apathy, anorexia, changes in faecal quality and alopecia on the tip of the tail. On clinical examination, a stiffness of the back legs was noted. Abdominal palpation revealed a hard immobile, irregular structure in the region of the last lumbar vertebrae. Subsequent radiography and ultrasonography suggested the presence of neoplasia. The following day the chinchilla was showing hindlimb paralysis, and there was severe self-trauma to the distal 5 cm of the tail. In view of the rapid clinical deterioration, the chinchilla was euthanased with the owner's consent. Macroscopic examination supported the clinical suspicion of neoplasia. Histopathological examination revealed a reactive osteoblastic osteosarcoma. To the author's knowledge, this is the first report of osteosarcoma in chinchillas.

An extradural chondroma originating in the cervical spine was diagnosed in an 8-year-old, intact male Chow-Chow that presented acute cervical pain and chronic right thoracic limb lameness. Myelographic images were within normal limits. With magnetic resonance (MR) imaging, an extradural mass was identified at the level of the C4-C5 vertebrae. This mass was excised, and the histologic diagnosis was chondroma. Fifteen months after surgery, the dog was clinically normal, and no regrowth of the mass was identified on follow-up MR images. Spinal chondromas are rare tumors in the dog, but should be considered as a rule out for contrast-enhancing extradural vertebral masses.

A 2.5 year-old female ferret had a stiff palpable mass arising from the dorsal surface of the thoracic (T) to lumbar (L) vertebrae with paralysis of the hind limbs. By myelography the dorsal and ventral lines of contrast were not observed in the area forwarded of L3. Grossly, the tumor encircled the dorsal vertebrae. Microscopically, tumor cells were proliferated intimately and were attached to the vertebrae surface involving surrounding fatty and connective tissues. The tumor consisted of fibroblastic cells with prominent cellular atypia. The bromodeoxyuridine (BrdU) labeling index to examine cellular kinetics was high (11.8%). Based on macro and micropathological features, the present tumor was diagnosed as periosteal fibrosarcoma arising from perivertebral connective tissue.

A spayed female Shetland sheep dog aged 12 years was presented for examination with ataxia and hindlimb paralysis. Extradural spinal cord compression was found at the level of vertebrae C6-C7 by radiography and myelocomputed tomography. A jelly-like mass (0.6 x 1.3 cm) was removed surgically. Histopathological findings were characterized by proliferation of vacuolated polygonal cells (physaliphorous cells) in a mucinous matrix and the presence of chondroid tissue shown immunohistochemically to express S-100. The physaliphorous cells were immunolabelled strongly for vimentin and S-100, and weakly for cytokeratin. A diagnosis of canine cervical chondroid chordoma was made. This is considered to be the first report of a chondroid chordoma originating from the cervical region of the spine in the dog.

An unusual clinical presentation of lymphoma with vertebral involvement in a dog is reported. A 20-month-old intact female Golden Retriever presented with progressive paraparesis and anorexia. Complete blood count and serum biochemistry profile demonstrated pancytopenia and hypercalcemia. Ventral fusion of the lumbar vertebrae by new bony tissue deposition was evident on X-ray and CT scan. Fine needle aspiration revealed neoplastic lymphoid cells in lymph nodes and bone marrow. Histologically, vertebral bone and osteophytes, liver, bone marrow, kidney, and lymph nodes were diffusely infiltrated by neoplastic, lymphoid cells, with scant cytoplasm and round hyperchromatic nuclei. Polyostotic and medullary T-cell lymphoma with spondylosis was diagnosed. Lymphoma mainly affecting bone is uncommon in the dog. The present case differs from previously described polyostotic lymphomas in clinical signs of the disease, mainly attributable to spondylarthrosis. In addition, lymphomatous proliferation was associated with osteoproductive lesions of the vertebrae.

This is the first report of feline solitary plasmacytoma of bone. We describe the clinical, clinico-pathological, radiographic and pathological findings of two successfully treated cats with long-term follow-up. The first case presented with spinal pain and neurological deficits. Radiographs demonstrated sclerosis of lumbar vertebra L6 and a myelogram confirmed interference to flow of contrast in the L4-7 region. A biopsy of L6 revealed neoplastic plasma cell infiltration. There was no evidence of paraproteinaemia on serum protein electrophoresis. The cat underwent hypofractionated megavoltage radiotherapy. Clinical signs resolved completely and 4 years after diagnosis the cat remains well and has no electrophoretically detectable paraproteinaemia. The second case presented with neurological deficits of the tail and spinal radiographs revealed extensive osteolysis of the sacrum. A biopsy of sacral bone demonstrated neoplastic plasma cell infiltration. The animal was normoglobulinaemic. The cat improved clinically with induction chemotherapy (melphalan and methylprednisolone). The same chemotherapeutics were continued at maintenance doses for 4.3 years, at which time there was recurrence of neurological deficits and a palpable sacral mass. Cytological examination of a fine needle aspirate confirmed recurrence of plasma cell neoplasia. A low concentration monoclonal paraproteinaemia was detected. Vincristine was administered resulting in resolution of neurological deficits and a palpably smaller sacral mass. Eighteen months into vincristine therapy, there was recurrence of clinical signs and the cat was euthanased, more than 6 years after the initial diagnosis.

An African pygmy hedgehog (Atelerix albiventris) was diagnosed with osteosarcoma of vertebral origin with compression of the spinal cord and spinal nerves. The only presenting sign was a self-mutilation of rear feet. Additional diagnoses included a well-differentiated splenic hemangiosarcoma, an undifferentiated sarcoma of the ascending colon, and membranoproliferative glomerulonephritis.

A case of vertebral osteoma observed in a female 4-year-old dromedary camel is presented. The patient showed a progressive ataxia, incoordination and finally a permanent recumbence position. Treatment was unfruitful and the animal was humanely euthanized. Postmortem examination revealed an expansive growth at vertebral body of the 10th thoracic vertebra, which was histologically classified as an osteoma. To the author's knowledge, this would be the first description of an osteoma in a camelid species.