Magnetic resonance imaging is the primary method used to diagnose canine glial cell neoplasia and non-infectious inflammatory meningoencephalitis. Subjective differentiation of these diseases can be ...difficult due to overlapping imaging characteristics. This study utilizes texture analysis of intra-axial lesions both as a means to quantitatively differentiate these broad categories of disease and to help identify glial tumor grade/cell type and specific meningoencephalitis subtype in a group of 119 dogs with histologically confirmed diagnoses. Fifty-nine dogs with gliomas and 60 dogs with non-infectious inflammatory meningoencephalitis were retrospectively recruited and randomly split into training (n=80) and test (n=39) cohorts. Forty-five of 120 texture metrics differed significantly between cohorts after correcting for multiple testing (false discovery rate <0.05). After training the random forest algorithm, the classification accuracy for the test set was 85% (sensitivity 89%, specificity 81%). Texture analysis was only partially able to differentiate the inflammatory subtypes (Granulomatous Meningoencephalitis (GME), Necrotizing Meningoencephalitis (NME), and Necrotizing Leukoencephalitis (NLE)) (out-of-bag error rate of 35.0%) and was unable to identify metrics that could correctly classify glioma grade or cell type (out-of-bag error rate of 59.6% and 47.5%, respectively). Multiple demographic differences, such as patient age, sex, weight, and breed were identified between disease cohorts and subtypes which may be useful in prioritizing differential diagnoses. Texture analysis of MR images with a random forest algorithm provided classification accuracy of inflammatory and neoplastic brain disease approaching the accuracy of previously reported subjective radiologist evaluation.
The occurrence of diabetic neuropathy in cats provides an opportunity to study the development and treatment of neurological complications not present in diabetic rodent models, where few ...pathological alterations are evident. The present study further defines pathological alterations in nerve biopsies from 12 cats with spontaneously occurring diabetes mellitus. Peroneal nerve biopsies displayed concurrent injury to both Schwann cells and axons of myelinated fibers that was remarkably similar to that present in human diabetic neuropathy. In addition to demyelination, remyelination (constituting 20-84% of the total myelinated fiber population) was indicated by fibers with inappropriately thin myelin sheaths. Unlike our previous investigations, striking axonal injury was apparent, and consisted of dystrophic accumulations of membranous debris or neurofilaments, as well as degenerative fiber loss resulting in a 50% decrease in myelinated fiber density. In spite of extensive fiber loss, regenerative clusters were apparent, suggesting that axonal regeneration was not completely frustrated. These data highlight the potential utility of feline diabetic neuropathy as a model that faithfully replicates the nerve injury in human diabetes mellitus.
Brainstem dysfunction resulting from central extension of infection is a life‐threatening complication of otitis media/interna (OMI) that has been described infrequently in dogs and cats. We review ...the clinical signs of disease, diagnostic findings, and results of surgical and medical treatments of brainstem disease attributable to otogenic intracranial infection in cats and dogs. Eleven cats and 4 dogs were examined because of acute, subacute, or chronic clinical signs of brain disease including central vestibular signs, altered mentation, abnormal posture/gait, cranial nerve deficits, and seizures. Results of a minimal database (CBC, serum biochemical panel, urinalysis, thoracic radiographs, and abdominal ultrasonographic images or radiographs) were within reference intervals in all animals. Magnetic resonance (MR) images of the head were acquired for all animals, and cisternal cerebrospinal fluid (CSF) from 9 of 11 cats and 3 of 4 dogs was examined. Surgical exploration and ventral bulla osteotomy were done for 12 of 15 animals, followed by 1–3 months of antibiotic therapy; the remaining animals were euthanized before treatment. In all animals, MR imaging was effective in characterizing the location and extent of the pathologic changes intracranially as well as within middle/inner ear structures. Results of CSF analysis were characteristic of bacterial infection in most of the animals with acute or subacute disease. Since long‐term outcome in all treated animals was very good to excellent, it was concluded that dogs and cats with intracranial disease secondary to extension of otitis media/interna have a good‐to‐excellent prognosis when the condition was diagnosed and was treated by surgical exploration and appropriate antibiotic therapy.
The recent application of neuroimaging techniques in veterinary neurology has led to the accurate localization of many types of intracranial lesions but has also created a clinical need, particularly ...with brain tumors, for a specific intraoperative diagnosis. For human brain tumors, a smear technique has been used successfully for many years to provide an extremely rapid, highly accurate intraoperative diagnosis. In similar smear preparations of intracranial lesions, obtained either by computed tomography (CT)-guided stereobiopsy or from a craniotomy, we have described distinguishing cytologic features of some primary spontaneous nervous system tumors in 80 dogs and 13 cats. A final diagnosis was confirmed by evaluation of paraffin-embedded sections from the same sample and, when appropriate, by immunocytochemical staining. Preliminary findings indicate that, in dogs and cats, this procedure is useful for rapid, accurate intraoperative diagnosis of many primary nervous system tumors. The distinguishing features of the canine and feline tumors bear a remarkably close resemblance to their human counterparts.
Although pure granular cell tumors have been reported in various sites in the dog, only one tumor has been reported in the central nervous system. Two dogs presented with neurologic signs had brain ...lesions detected by magnetic resonance imaging in the area of the olfactory bulbs and frontal cortex. In both dogs, a clinical diagnosis of a granular cell tumor was made from tissues obtained from stereotactic biopsies guided by computed tomography. Surgical removal of the tumors was followed by histopathologic, ultrastructural, and immunocytochemical characterization. Although not conclusive, these studies indicated that the granular cells were not of leucocyte origin but may have been derived from the meninges. One dog died 12 months after surgery, and the other was alive 4 months later.
This report describes the results of CT‐guided stereotactic brain biopsies performed on 50 consecutive dogs using a modified Pelorus Mark III Stereotactic System. Based on available histopathologic ...samples (stereotactic biopsy n= 50, surgery n= 17, necropsy n= 9) the patient population consisted of 34 dogs with primary brain tumors, 2 with invasive nasal adenocarcinomas, and 13 with non‐neoplastic brain lesions. Brain tissue was not obtained from one dog. In 22 dogs a final diagnosis was made from tissue subsequently obtained from surgical resection or at necropsy. The final diagnosis was in agreement with the stereotactic biopsy diagnosis in 20 of these 22 dogs. In 17 other dogs without follow‐up, stereotactic biopsy provided a diagnosis of a specific primary brain tumor subtype. Postoperative complications associated with the biopsy procedure were assessed in 41 dogs. The other 9 dogs either went directly to surgery (n= 7) or were killed (n= 2) immediately after the biopsy procedure. Thirty‐six dogs recovered without apparent clinical complications. Postoperative clinical complications in the remaining 5 dogs included transient epistaxis (1 dog), transient exacerbation of cerebellar signs (1 dog), obtundation progressing to coma (1 dog), and medically uncontrollable seizures (2 dogs). The latter 3 dogs with severe neurologic complications all had large primary brain tumors and had been receiving high doses of phenobarbital and glucocorticoids to control seizures at the time of biopsy. These results suggest that this CT‐guided biopsy procedure can provide an accurate pathologic diagnosis of brain lesions detected by CT and MR neuroimaging. Further refinement of both technique and case selection is expected to reduce the rate of clinical complications and to improve the accuracy of the procedure.
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A 6‐year‐old spayed Labrador Retriever Mix dog was evaluated for a 2‐week history of progressive generalized weakness and reluctance to stand. Physical examination revealed severe weakness with ...obtunded mentation, head tilt, bilateral nystagmus, and decreased vision. CBC findings included mild nonregenerative anemia, marked thrombocytopenia, and a few atypical mononuclear cells on the blood film. The cells were 15–30 μm in diameter and had round to oval to reniform centrally placed nuclei with stippled chromatin, prominent nucleoli, and abundant basophilic cytoplasm with numerous discrete vacuoles and, occasionally, small azurophilic granules. Similar cells were found in bone marrow. On histologic examination of tissues collected at necropsy, neoplastic cells were detected in bone marrow, hepatic sinusoids, cerebral and meningeal vessels, and in capillaries of the heart, renal interstitium, small intestinal submucosa, and muscularis, and alveolar septa. A small discrete mass in the right atrium consisted of similar neoplastic cells, and the spleen was diffusely infiltrated. Tissue distribution was suggestive of intravascular lymphoma. Neoplastic cells in tissue sections were immunoreactive for vimentin, CD18, CD45, and granzyme B and lacked immunoreactivity for cytokeratin. Neoplastic cells on bone marrow aspirate smears and blood films lacked immunoreactivity for CD3, CD79a, CD1c, CD11b, CD11c, CD11d, and E‐cadherin. In the absence of immunophenotypic evidence for the neoplastic cells being derived from B‐cell, T‐cell, or histocytic/dendritic lineages and the lack of clonal antigen receptor gene rearrangement(s), along with positive immunoreactivity for granzyme B, a tumor of NK cells was considered likely. Based on current knowledge, this is the first report of canine intravascular lymphoma, of probable NK cell origin, with peripheral blood involvement.
Dendritic cell leukemia in a Golden Retriever Allison, Robin W.; Brunker, Jill D.; Breshears, Melanie A. ...
Veterinary clinical pathology,
June 2008, 2008-Jun, 2008-06-00, 20080601, Letnik:
37, Številka:
2
Journal Article
Recenzirano
: An 8‐year‐old castrated male Golden Retriever was evaluated for decreased appetite, lethargy, and labored breathing of 1‐week duration. Bilateral pulmonary infiltrates, hepatomegaly, and ...splenomegaly were present. Results of a CBC revealed marked leukocytosis (62,600/μL; reference interval 4000–15,500/μL) and large numbers of atypical cells (30,700/μL) with abundant cytoplasm. There was no concurrent anemia, neutropenia, or thrombocytopenia. Morphology of the atypical cells was most consistent with a histiocytic origin. Similar cells were identified in bone marrow aspirates, and were morphologically suggestive of the macrophage variant of disseminated histiocytic sarcoma. However, flow cytometry of the abnormal circulating cells revealed CD1c, CD11c, and major histocompatibility complex (MHC) Class II expression without expression of CD11d or lymphoid markers, consistent with myeloid dendritic antigen‐presenting cells. At necropsy, the splenic architecture was effaced by neoplastic histiocytes that were also infiltrating lung, liver, an abdominal lymph node, myocardium, an bone marrow. Immunohistochemistry of the splenic neoplastic cells confirmed dendritic cell origin (CD1c+, CD11c+, MHC II+, no expression of CD11d and lymphoid markers). To the authors' knowledge, this is the first report of canine dendritic cell leukemia—in this instance accompanied by marked tissue infiltration.
Extradural spinal synovial cysts in nine dogs Dickinson, P. J.; Sturges, B. K.; Berry, W. L. ...
Journal of small animal practice,
October 2001, Letnik:
42, Številka:
10
Journal Article
Recenzirano
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.
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