Surgical management of a recurrent spinal meningioma in a cat

A 13-year-old male neutered Persian crossbred cat was evaluated for hindlimb paresis, ataxia and urinary incontinence that had been progressing over the previous 3 months. Neurologically, the cat had thoracolumbar spinal cord deficits and a myelogram detected the presence of a mass compressing the thoracic spinal cord. A hemilaminectomy was performed to excise the soft tissue mass, subsequently identified histologically as a psammomatous meningioma. The cat regained ambulatory function and continence following surgery until a recurrence of paresis and ataxia 36 months later. A second myelogram suggested local recurrence of the tumour, which was confirmed by histological examination of the tumour after its removal at a second laminectomy. The cat again regained normal neurological function, until a further recurrence 16 months after the second surgery. The meningioma was surgically debulked a third time and the cat regained ambulation and continence postoperatively. This case demonstrates the successful use of repeated surgical resection in the management of a recurrent spinal meningioma in a cat. The cat was ambulatory and continent at a follow-up examination 63 months after the initial presentation.     

Multiple myeloma with central nervous system involvement in a cat

CASE DESCRIPTION: A 1.5-year-old spayed female domestic shorthair cat was admitted for hind limb locomotor difficulties and signs of pain along the lumbar portion of the vertebral column. At the time of referral, the cat was paraparetic with deficits in the spinal reflexes of the hind limbs. Neuroanatomic localization was at the L6-S2 spinal cord segments, corresponding approximately to the region of the L4-L6 vertebral bodies. CLINICAL FINDINGS: Radiography revealed a mixed osteolytic-proliferative lesion within the body of L5 involving the cranial end plate, as well as punctate radiolucencies in the distal portion of the femur. Magnetic resonance imaging revealed an intramedullary spinal cord lesion along with extensive meningeal and nerve root lesions in the area of the L4-L6 vertebral bodies. Cytologic analysis of a bone marrow aspirate from the right trochanteric fossa revealed a substantial plasma cell infiltrate. Analysis of CSF revealed a high protein concentration and morphologically abnormal plasma cells. Urine, but not serum, protein electrophoresis revealed a sharp gamma-globulin peak consistent with a monoclonal band of Bence-Jones proteins. The diagnosis was multiple myeloma. TREATMENT AND OUTCOME: The cat was treated with melphalan and prednisolone. A rapid clinical response was reported, and by week 3 after diagnosis, the cat's locomotion and behavior had normalized. However, by month 4, multifocal neurologic deficits were evident. The cat was euthanized at 9 months because of tetraparesis and substantial weight loss. CLINICAL RELEVANCE: To our knowledge, this is the first report of myeloma in a cat that had electrophoretically detectable light chain proteinuria but lacked a detectable serum monoclonal gammopathy.     

Acquired arachnoid cyst in a cat

A 5-year-old Birman cat presented with paraparesis associated with a fracture of the third thoracic vertebra and was managed conservatively. Voluntary function was regained over the next 6 months, but the cat was referred 4 years after the trauma because of recurrence of hindlimb paresis and ataxia. Magnetic resonance imaging (MRI) showed a spinal arachnoid cyst at the level of the fourth thoracic vertebra, which was treated surgically by dorsal laminectomy and durectomy, and hindlimb function subsequently recovered. The cat re-presented 4 years later for recurrent hindlimb paresis. Myelography and computed tomography–myelography (CT-M) showed dorsolateral pooling of cerebrospinal fluid (CSF) at the previous laminectomy site. The neurological signs after the second surgery improved, but not as much as after the first surgery and the cat remained ataxic with moderate paresis. Seven months later repeat CT-M revealed an atrophic spinal cord, but negligible pooling of CSF at the previous site of the arachnoid cyst. The cat could walk, but was being treated for self-induced trauma of the left hindlimb that was thought to be related to paraesthesia. The neurological signs gradually deteriorated over 3 months and the cat was euthanased.     

Corneal hemangiosarcoma in a cat

A 10 year-old castrated male Domestic Short-hair cat with a history of chronic bilateral keratitis was referred for assessment of a red, elevated mass involving the left cornea. The rapid growth of the mass, over a month period in combination with pronounced vascularization and invasion of the corneal surface suggested an aggressive inflammatory or neoplastic process. Following keratectomy, the lesion was diagnosed histopathologically as a hemangiosarcoma. The tumor recurred locally within 3 weeks and enucleation was performed. Histopathologic examination of the globe confirmed the diagnosis and did not reveal infiltration of the limbus and conjunctiva. No signs of local recurrence or metastatic disease have been observed 18 months following enucleation. To the authors' knowledge this is the first case of primary corneal hemangiosarcoma described in the feline species.     

Light-chain multiple myeloma in a cat.

A diagnosis of light-chain multiple myeloma was made in an 11-year-old male American Shorthair cat. The cat showed atypical plasma cell infiltration in the bone marrow, biclonal gammopathy caused by polymerization of myeloma protein (M-protein), and Bence-Jones proteinuria. The M-protein in the serum of the cat was analyzed by using 12% sodium dodeyl sulfate (SDS) polyacrylamide gel electrophoresis with Coomassie brilliant blue staining. An intense band with a size of 27 kDa, the size of the immunoglobulin light chain, was clearly observed, whereas the band corresponding to the immunoglobulin heavy chain (59 kDa) was undetectable. The 27-kDa band was confirmed to be an immunoglobulin light chain by Western blotting by using antibodies for feline immunoglobulin. These data suggested that the neoplastic plasma cells produce light chain only, leading to the diagnosis of light-chain multiple myeloma in the cat.     

Spinal nephroblastoma in an Irish wolfhound

A 1-year-old Irish wolfhound was presented with a history of slowly progressive left pelvic limb paresis. A neurological examination demonstrated bilateral deficits referable to the thoracolumbar spinal cord. Lumbar cerebrospinal fluid contained neoplastic cells. An intradural, extramedullary mass was demonstrated by myelography at the caudal aspect of T13. Surgical excision was abandoned owing to severe macroscopic damage to, and apparent infiltration of, the cord, and the dog was euthanased. The tumour was diagnosed histologically as an extrarenal nephroblastoma. Nephroblastoma should be suspected in young, large-breed dogs with intradural extramedullary masses over spinal segments T10-L2. The prognosis for complete recovery after surgical excision is guarded to poor.     

Oral and peripheral vestibular signs in a cat with squamous cell carcinoma

A 13-year-old female, spayed cat had oral and vestibular signs resulting from a 3-cm mass extending from the tympanic membrane to the nasopharynx. Radiography revealed a soft-tissue density in the tympanic bulla. Cytologic examination and biopsy confirmed the presence of a squamous cell carcinoma. Squamous cell carcinoma causes vestibular signs in the cat. In this cat, squamous cell carcinoma, involving the middle and inner ear, resulted in oral and vestibular signs.     

Eosinophilic meningomyelitis associated with T‐cell lymphoma in a cat

A 12‐year‐old cat was presented for evaluation of progressive tetraparesis. Magnetic resonance imaging of the cervical spine demonstrated T2‐hyperintensity, and contrast enhancement within the C4–C7 spinal cord, with marked meningeal contrast enhancement and segmental nerve root thickening. Lumbar cerebrospinal fluid contained 407 total nucleated cells/μL, with 99% eosinophils. The cat transiently improved with prednisolone, clindamycin, and ivermectin therapy, but subsequently worsened and was euthanized. Necropsy revealed an asymmetric infiltration predominantly of the white matter, meninges, and nerve roots of the C4–C6 spinal cord segments by an unencapsulated, poorly demarcated neoplasm composed of atypical lymphocytes admixed with eosinophils, causing perivascular hemorrhage and lytic necrosis. The neoplastic cells were immunoreactive for CD3, ultimately confirming T‐cell lymphoma.     

Fibrocartilaginous embolism in a cat

A nine-year-old cat was presented with a history of an acute onset of paraplegia. On the basis of the neurological examination, the lesion was localised between the fourth lumbar and third sacral segments (L4 to S3) of the spinal cord. Investigations included radiography, myelography, cerebrospinal fluid analysis, routine haematology and biochemistry, feline leukaemia virus testing and urinalysis. A definitive diagnosis was not achieved and the cat was euthanased 12 days after presentation. Post mortem examination revealed infarction of the spinal cord secondary to fibrocartilaginous embolisation. This is the first reported case of fibrocartilaginous embolism in the cat in the UK.     

Metastatic carcinoma in the ulna of a cat secondary to a suspected pulmonary tumour

A 14-year-old male neutered Burmese cat presented for investigation of right fore limb lameness that was non-responsive to anti-inflammatory drugs and opioids. Thoracic radiography showed multiple pulmonary soft tissue nodules and a larger cavitated mass. Right elbow radiographs revealed marked peri-articular proliferation of new bone and periosteal reaction primarily affecting the ulna. Histopathological examination of an incisional biopsy of the right ulna revealed neoplastic proliferation of epithelial cells; this was confirmed as a poorly differentiated carcinoma with immunohistochemistry. Amputation of the right fore limb was performed at the owner's request. After surgery, radiographs of the limb showed progression of bone proliferation. Repeat pathological analysis confirmed a metastatic carcinoma. The cat deteriorated 3 days after surgery and was euthanased a week later as a result of severe respiratory distress. This case represents an unusual case of metastasis of a suspected primary lung tumour to the ulna in a Burmese cat.     

A sacro‐caudal spinal cord choroid plexus papilloma in a shar‐pei dog

A seven‐year‐old shar‐pei dog was referred because of severe lumbosacral pain and faecal incontinence of 20 days’ duration. Neurological examination was characterised by plegic tail, absence of perineal reflex, dilated anus, perineum and tail analgesia, and severe lumbosacral pain. The neurological clinical signs were suggestive of a selective lesion involving sacral and caudal spinal cord segments and/or related nerve roots. A magnetic resonance imaging of lumbosacral spine was performed and was suggestive of an intradural lesion. Primary or secondary neoplasia was considered as the most probable differential diagnosis. The dog was euthanased upon the owner's request. Histopathological examination confirmed the presence of an intradural‐extramedullary neoplastic tissue enveloping intradural tract of spinal nerve roots. On the basis of histological and immunohistochemical findings, a diagnosis of well‐differentiated choroid plexus papilloma was made. To the authors's knowledge, this is the first case of primary or metastatic spinal choroid plexus papilloma in dogs.     

Vertebral lymphosarcoma in a cat

Lymphosarcoma of the cauda equina in a domestic shorthair cat invaded the body of L7 and cranial portion of the sacrum. Clinical signs consisted of acute ambulatory paraparesis, tail paralysis, and dyschezia. Radiographically, there was evidence of bone lysis. Surgical exploration yielded a diagnosis, but did not induce improvement in the cat, which was subsequently euthanatized. Neurologic signs were similar to those associated with sacral nerve root avulsion injuries in cats.     

RADIOGRAPHIC DIAGNOSIS: CARTILAGINOUS EXOSTOSES IN A DOG

A 6 month-old dog was examined for progressive paraparesis. On physical examination bony malformations were palpated over the cranial lumbar vertebral bodies and on the left metatarsal bone. Neuroanatomic lesion localization for the paraparesis was a T3-L3 spinal cord lesion. Radiographs confirmed bony masses at L1-L2 and on the left 3rd metatarsal bone. Magnetic resonance imaging was performed from T3-L3. Severe spinal cord compression was identified at L1-L2. Surgical decompression and biopsy confirmed the mass to be cartilaginous exostoses. This paper is an example of cartilaginous exostoses imaged with MR.     

Large anaplastic spinal B‐cell lymphoma in a cat

Abstract: 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.     

Transitional cell carcinoma forming a perirenal cyst in a cat

An eight-year-old, neutered male Burmese cat presented with five days vomiting and anorexia. Physical examination, clinical pathology and diagnostic imaging findings suggested a perirenal pseudocyst. After partial resection of the perirenal capsule clinical signs temporarily resolved, but the cat was euthanased 34 days postoperatively as a result of seizures and recurrence of vomiting. Postoperative histopathology showed neoplastic transitional cells within and lining the resected perirenal capsule; a diagnosis of transitional cell carcinoma was confirmed post-mortem. To the authors' knowledge, this is the first report of this presentation of transitional cell carcinoma. Transitional cell carcinoma should be a differential diagnosis for the aetiology of perirenal pseudocyst.     

Metastatic Tumor in Pregnancy: Placental Germ Cell Tumor With Metastasis to the Foal

A placental mass was observed in an otherwise-healthy Quarter Horse mare; subsequently, the mare's 52-day-old foal was examined because of hind limb ataxia, urinary incontinence, and raised lesions of the distal limbs. Clinical and biochemical findings were supportive of liver disease and lumbosacral injury. Ultrasonographic evaluation of the abdomen suggested a liver mass, which was confirmed with computed tomography (CT) and determined to be neoplastic via histopathologic evaluation of a liver biopsy sample. Initial histopathology suggested a germ cell tumor. Regions of lysis affecting both femurs and third metacarpal bones and a complete oblique sagittal fracture through the body of the first sacral vertebra were present on CT. Supportive care was provided until CT confirmation of diffuse hepatic neoplasia and vertebral fracture. Necropsy revealed a large multinodular mass within the liver and a pathologic fracture of the first sacral vertebral body. Histopathologic comparison between neoplastic cells examined from the placenta and foal confirmed metastases of a germ cell tumor. Placental tumors are rare in all species; however, when noted in horses, clinicians should be aware of the possibility of metastatic spread to the foal.     

Spinal dural ossification causing neurological signs in a cat

A six-year-old Ragdoll cat underwent examination due to a six-month history of slowly progressive gait abnormalities. The cat presented with an ambulatory tetraparesis with a neurological examination indicating a C1-T2 myelopathy. Radiographs of the spine showed a radiopaque irregular line ventrally in the vertebral canal dorsal to vertebral bodies C3-C5. In this area, magnetic resonance imaging revealed an intradural extramedullary/extradural lesion compressing the spinal cord. The spinal cord was surgically decompressed. The cause of the spinal cord compression was dural ossification, a diagnosis confirmed by histopathological examination of the surgically dissected sample of dura mater. The cat gradually improved after the procedure and was ambulating better than prior to the surgery. The cat’s locomotion later worsened again due to ossified plaques in the dura causing spinal cord compression on the same cervical area as before. Oral prednisolone treatment provided temporary remission. Ten months after surgery, the cat was euthanized due to severe worsening of gait abnormalities, non-ambulatory tetraparesis. Necropsy confirmed spinal cord compression and secondary degenerative changes in the spinal cord on cervical and lumbar areas caused by dural ossification. To our knowledge, this is the first report of spinal dural ossification in a cat. The reported cat showed neurological signs associated with these dural changes. Dural ossification should be considered in the differential diagnosis of compressive spinal cord disorders in cats.     

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.     

Vitamin D-dependent rickets type II in a cat

A cat with clinical signs Indicating rickets was diagnosed as having a defect of vitamin D receptors. Clinical signs had been seen from four months of age. Treatment with calcium supplementation and various forms of vitamin D did not alter plasma calcium levels or reverse skeletal lesions of lateral antebrachial bowing, lumbar spinal lordosis and costochondral beading. Analgesics were effective for relieving skeletal pain during the bone growth phase and were withdrawn when the animal reached skeletal maturity. Therapy for hip osteoarthritis was given from five years of age until the cat was euthanased at nine years of age as a result of refractory hip pain.