Conservative treatment of a synovial cyst in a golden eagle (Aquila chrysaetos) with triamcinolone acetonide.

In human and veterinary medicine, the treatment of synovial cysts involves medical or surgical approach. When medical treatment is chosen, triamcinolone acetonide is one of the most used drugs. In this case, intracystic triamcinolone was administered for the treatment of a non-infectious elbow synovial cyst in a subadult female Golden eagle (Aquila chrysaetos), unable to fly. The bird was brought to a wildlife rescue center after an aerial fight with a conspecific. After the treatment, no clinically detectable adverse effects were noted and there was no recurrence within two weeks. Given the improvement of the clinical conditions and the recovery of flight ability, the animal was released back into the wild 17 days after administration of the drug.

Synovial Cysts and Myxomas in 16 Cats.

This report describes the clinical and pathologic characteristics of cystic and myxomatous lesions of synovial joints in 16 cats. The average age was 13.4 years. The elbow was most commonly affected (12/16), and all lesions were unilateral. Degenerative joint disease was a frequent concurrent but bilateral condition. The lesions consisted of fluid-filled cysts lined by synoviocytes (3 cases), solid foci of stellate cells in a myxomatous matrix (2 cases), or a combination of the two (11 cases). In some cases there were areas of transition between the cystic and myxomatous lesions. Mitoses and other features of malignancy were rare to nonexistent. In the 13 cats with follow-up information, the lesion gradually increased in size over a period of years. None of the cats died or were euthanized because of this lesion. We propose that some cats with degenerative joint disease develop synovial cysts, which have the potential to transform to a synovial myxoma.

Spontaneous regression of extradural intraspinal cysts in a dog: a case report.

BACKGROUND: Extradural intraspinal cysts are fluid accumulations that appear to be associated with increased motion at vertebral joints. CASE PRESENTATION: We report the spontaneous regression of lumbar and lumbosacral cysts (presumably synovial cysts) and the unusual occurrence of an S1-2 extradural intraspinal cyst in a dog. The dog presented with lumbosacral pain. Six extradural intraspinal cysts were observed on high-field magnetic resonance imaging from L5-6 to S1-S2. The cysts between L5-6 and L7-S1 ranged from 0.12 to 0.44cm2 at their largest area. The largest cyst was located at S1-2 (left), measuring 0.84 cm2 at its largest view. The dog was medically managed. A follow-up magnetic resonance imaging scan was obtained 3.5 years after the first imaging. All cysts except the one at S1-2 had reduced in size. Mean reduction in size was 59.6% (35-81%). CONCLUSIONS: In summary, we report a case with multiple extradural intraspinal cysts that underwent spontaneous regression of all but one cyst during a 3.5-year follow-up period. Whether this is a single occurrence, or is part of the natural history of these cysts in the lumbosacral region of dogs, remains to be established. Spontaneous regression of intraspinal cysts had not been described in dogs.

Lameness caused by an extradural lumbosacral foraminal synovial cyst in three German Shepherd Dogs.

Three German Shepherd Dogs that were presented for investigation of chronic unilateral hindlimb lameness and pain in the lumbosacral region were diagnosed with an intraspinal, extradural synovial cyst and reactive fibrosis protruding into the foramen of the lumbosacral articulation using magnetic resonance imaging and histology. This extradural mass compressed the nerve root in the foramen and the cauda equina. During a dorsal laminectomy and unilateral partial foraminotomy, the cyst and the fibrotic tissue were removed with the aid of a 2.4 mm 30° arthroscope for visualization of the foramen. The fibrotic tissue surrounding the cysts was in all cases confluent with the annulus of the intervertebral disc. The histological examination confirmed the diagnosis of a synovial cyst in all three cases by finding inflamed synovial membrane in the samples from the wall of the cyst as well as reactive fibrosis and cartilaginous metaplasia in the surrounding tissue. The three patients improved after the surgery and were pain free during the follow-up evaluations.

Cystic Abnormalities of the Spinal Cord and Vertebral Column.

Cystic lesions of the vertebral column and spinal cord are important differential diagnoses in dogs with signs of spinal cord disease. Synovial cysts are commonly associated with degenerative joint disease and usually affect the cervical and lumbosacral regions. Arachnoid diverticulum (previously known as cyst) is seen in the cervical region of large breed dogs and thoracolumbar region of small breed dogs. This article reviews the causes, diagnosis, and treatment of these and other, less common, cystic lesions.

Use of greater omentum in the surgical treatment of a synovial cyst in a cat.

A 13-year-old cat was diagnosed with a synovial cyst originating from the glenohumeral joint. The cat presented with severe front limb lameness and a non-painful fluctuating swelling on the medial aspect of the humerus. Radiographic examination showed severe bilateral shoulder osteoarthritis with osteophyte formation. The mass was surgically resected and histopathology confirmed the diagnosis of a synovial cyst. Three weeks postoperatively the cyst recurred. Surgical resection was repeated followed by omentalisation of the defect. Throughout the following 3 months the cyst did not recur. Unfortunately, for reasons unrelated to the presented disease, the cat was euthanized shortly afterwards, therefore making a long-term follow-up impossible.

Surgical management of vertebral synovial cysts in a rabbit (Oryctolagus cuniculus).

CASE DESCRIPTION: An approximately 8-month-old female Miniature Lop rabbit (Oryctolagus cuniculus) was evaluated because of an acute onset of progressive paraparesis. CLINICAL FINDINGS: The rabbit was ambulatory paraparetic, and results of neurologic examination were consistent with a myelopathy localizing to the T3-L3 spinal cord segments. Evaluation with CT myelography revealed focal extradural spinal cord compression bilaterally at the level of the articular process joints of T12-L1. TREATMENT AND OUTCOME: A Funkquist type A dorsal laminectomy was performed at T12-L1, and the vertebral column was stabilized with pins and polymethylmethacrylate-based cement. Multiple vertebral synovial cysts were confirmed on histologic evaluation of the surgically excised tissues. The rabbit was nonambulatory with severe paraparesis postoperatively and was ambulatory paraparetic at a recheck examination 7 weeks after surgery. Fourteen weeks after surgery, the rabbit appeared stronger; it walked and hopped slowly but still fell and dragged its hindquarters when moving faster. Thirty-seven weeks after surgery, the neurologic status was unchanged. CLINICAL RELEVANCE: Although thoracolumbar myelopathy in rabbits is commonly secondary to vertebral fracture, vertebral synovial cysts should be considered a differential diagnosis for rabbits with slowly progressive paraparesis. Decompressive surgery and stabilization can result in a good outcome for rabbits with this condition.

Ventral occipito-atlanto-axial fluid-filled lesion causing dynamic spinal cord compression in a cat.

Cystic lesions affecting the vertebral canal or spinal cord have rarely been reported in cats. A 3-year-old female neutered domestic longhair cat presented for evaluation of a 2-year-history of episodes of ataxia and paresis affecting all limbs. Neurological examination was consistent with a lesion in the C1-C5 spinal cord segments. Magnetic resonance imaging (MRI) showed a fluid-filled lesion at the occipito-atlanto-axial region causing dynamic spinal cord compression on flexion of the neck. The imaging characteristics were compatible with a juxta-articular cyst. To our knowledge, this is the first report of a fluid-filled lesion causing dynamic cervical spinal cord compression in a cat and highlights the importance of performing flexion-extension MRI views in diagnosing cases with dynamic spinal cord compression.

Equine articular synovial cysts: 16 cases.

OBJECTIVE: To report the clinical findings, diagnosis, treatment and outcome of equine patients with articular synovial cysts. STUDY DESIGN: Retrospective case series. ANIMALS: Horses (n = 16) with articular synovial cysts. METHODS: Horses diagnosed with articular synovial cysts (1988-2009) at 2 veterinary teaching hospitals were studied. Signalment, history, clinical signs, diagnostic methods and treatment were retrieved and telephone follow-up was obtained. RESULTS: Sixteen horses with articular synovial cysts were identified. Lameness was the reason for referral in most (n = 9) horses. Diagnosis was based on a combination of palpation and imaging studies, including radiography, ultrasonography and/or arthrography. Excision of the cyst was performed in 8 horses. Outcome was available for 4 surgically and 2 conservatively treated horses. Lameness resolved in 3 horses treated surgically and the 4th died for unrelated reasons. The 2 conservatively treated horses performed satisfactorily for the rest of their career. CONCLUSIONS: Equine articular synovial cysts are rare and can be associated with lameness. The cysts had a synovial lining in all horses where it was assessed. Surgical excision may be successful in resolving the lameness and allowing selected horses to return to work.

Stifle synovial cyst in a Labrador Retriever with concurrent cranial cruciate ligament deficiency.

A seven-year-old Labrador Retriever dog was presented with the complaint of chronic left hindlimb lameness. A diagnosis of partial rupture of the left cranial cruciate ligament with concurrent cranio-medial synovial cyst formation was made. This cystic structure was assumed to be communicating with the stifle joint. There was no evidence of a meniscal tear, but superficial fibrillation of the axial border was present. Surgical excision of the cyst with concurrent treatment of the cranial cruciate ligament deficiency by tibial tuberosity advancement was performed with a successful outcome. Whilst commonly encountered in humans, synovial cysts are uncommon in dogs. To the authors' knowledge this is the first reported case of synovial cyst formation in the stifle of a dog.

Synovial cyst of the fifth digit in a cat.

A synovial cyst of the fifth digit of the left forelimb in a 15-year-old cat was diagnosed. Radiographs showed severe osteoarthritis of the interphalangeal and metacarpophalangeal joints with soft tissue swelling. An ultrasound examination of the digit revealed a cystic structure. Following amputation of the digit, the cyst recurred 3 months later palmar to the carpus and metacarpus. The aetiology of synovial cysts is discussed.

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.

Synovial cysts associated with cauda equina syndrome in two dogs.

OBJECTIVE: To report synovial cysts associated with cauda equina syndrome in 2 dogs. STUDY DESIGN: Clinical cases. ANIMALS: Two German Shepherd dogs. METHODS: After magnetic resonance imaging detection, cysts were surgically removed via dorsal laminectomy. RESULTS: Six and 8 months after surgery, both dogs were free of clinical signs and no pain was elicited on lumbosacral joint manipulation. CONCLUSION: Although described in dogs, cysts at the lumbosacral joint might cause compression of the cauda equina nerve roots. Radical excision of the cyst capsule can result in resolution of clinical signs. CLINICAL RELEVANCE: Synovial cysts should be considered in the differential diagnosis of dogs with cauda equina compression syndrome when lumbosacral degenerative joint disease is present.

First cases of animal diseases published since 2000. 1. Dogs.

In this first article of a series of papers listing first case reports of animal diseases published since 2000, the following 19 cases of dog diseases are discussed: Blastomycotic granuloma involving the cranial vena cava. Congenital myocardial hamartoma. Discospondylitis: three cases caused respectively by Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus epidermidis. Dystrophin deficient muscular dystrophy in a Labrador Retriever. Emphysematous prostatitis. Erythema multiforme major caused by a Parvovirus infection of keratinocytes. Hemochromatosis due to repeated blood transfusions. Intraspinal synovial cyst. Juvenile nephropathy in the Collie and the Irish Wolfhound. Primary cerebellar cortical degeneration (abiotrophy) in a Scottish terrier. Primary pulmonary artery chondrosarcoma. Renal dysplasia in a Bull Mastiff. Rhabdomyosarcoma (botryoid sarcoma) of the urinary bladder in a Maltese. Spinal mast cell tumor. Spongiform degeneration of the white matter in the central nervous system of Australian Cattle dog. Systemic pasteurellosis caused by Pasteurella canis. Thymic hemorrhage caused by dicumarol intoxication. Undimerized biclonal gammopathy with a single heavy chain class IgA in a dog with multiple myeloma. After a short introduction, the bibliographical data and the abstract of the author(s) and mostly some additional information derived from the article are given. The article will be regularly updated adding overlooked as well as new first reports.

Extradural spinal synovial cysts in nine dogs.

Nine dogs presenting for investigation of cervical or thoracolumbar myelopathies were diagnosed with extradural spinal synovial cysts. Degenerative disease affecting the articular facets or intervertebral discs was present on plain spinal radiographs in all cases. Myelography was consistent with dorsolateral, extradural spinal cord compression. Two groups of dogs were identified: (1) young, giant breed dogs with multiple cysts involving one or more levels of the cervical spinal cord; and (2) older, large breed dogs with solitary cysts involving the thoracolumbar spinal cord. The synovial cysts constituted the major compressive lesions in four of the dogs. Analysis of lumbar cerebrospinal fluid demonstrated albuminocytological dissociation, consistent with chronic compressive myelopathy, in six dogs. All dogs underwent decompressive surgery and the diagnosis of synovial cysts was confirmed histologically. The mean follow-up period was 17 months (range four to 36 months). At the time of follow-up, all dogs were fully ambulatory with improved neurological function compared with that at initial presentation.