1,721,052 research outputs found
EPIDEMIOLOGY OF NEOPLASIA IN FERRET: 856 CASES (2000-2010)
No full textIntroduction: Ferrets are among the most common non-conventional companion animal, and are particularly prone to neoplastic diseases. The aim of this study is to investigate the epidemiology of neoplasms in ferret in Italy.
Materials and Methods: Cases comprised biopsy samples and postmortem specimens submitted between 2000 and 2010 at the veterinary histopathological service at University of Milan. Signalment and histopathological features were retrieved from archived reports. The total number of submitted samples was used to calculate the prevalence of neoplasms.
Results: during an 11 years period 908 submissions were retrieved, 688 of which met the inclusion criteria (75,77%). Multiple neoplasms were common, consequently a total of 856 tumours were evaluated. The endocrine (63,8%), integumentary (14,7%) and the hemolymphatic systems (8,9%) were the most common affected. The age of affected ferrets ranged from 5 months to 10 years. Cutaneous squamous cell carcinomas (SCC) were always associated with sebaceous gland neoplasms, A significant number of abdominal spindle cell tumour with unknown origin was also observed (2,6%). Angiosarcomas were more commonly located in the skin and liver, while splenic cases were not evidenced.
Conclusion: The most common neoplasms diagnosed in this study paralleled the previously reported findings. Association between SCC and sebaceous gland neoplasm, and the origin of intrabdominal spindle cell neoplasm needed to be further investigated
The controversial histologic classification of canine subcutaneous whorling tumours: The path to perivascular wall tumours
No full textSubcutaneous spindle cell tumours characterized by whorling growth patterns are common in dogs and are identified as a distinct entity. These tumours were misnamed as hemangiopericytomas (HPCs) because of some minor morphological parallels with their human counterparts. In veterinary medicine, the cell of origin of HPC has been under debate for a long time. Some authors have suggested a perivascular origin while others a perineural one. The evidence of the orientation of the neoplastic cells around the vessels and the expression of contractile proteins supported a perivascular origin while S100 expression and an inconsistent vascular connection supported a perineural origin. Despite the morphological similarities with peripheral nerve sheath tumours in humans, the perineural origin was supported mainly by the expression of markers with low specificity. On the contrary, the majority of studies have supported the perivascular origin of ‘old’ canine HPC. Since a variable degree of myoid-pericytic differentiation was described, the term perivascular wall tumours (PWTs) were suggested to substitute HPC. Once the diagnostic criteria of PWTs were defined, the clinical behaviour and prognostic variables were investigated, demonstrating differences as compared with the group of canine soft tissue sarcomas (STSs) in general. PWTs are less aggressive, mostly locally invasive, and rarely metastasizing. Their behaviour seems to be less influenced by histological grade, suggesting that canine STSs are heterogeneous. The study of the biological behaviour of specific STS tumour types may be valuable in detecting differences which have passed unnoticed when STSs have been studied concomitantly
Spindle cell lipoma in the dog: histological diagnostic features.
No full textIntroduction: Canine spindle cell lipoma (SCL) is an uncommon benign spindle cell tumour that might be misdiagnosed as soft tissue sarcoma (STS) because of the high cellularity and paucity of mature adipose tissue. The aim of this report was to define the typical histopathological features of canine SCL.
Materials and Methods: Dog signalment, tumour size and site were retrieved from medical records. Haematoxylin and eosin, Masson’s trichrome, alcian blue and PAS staining and immunohistochemistry for vimentin, smooth muscle actin (SMA), S100, factor VIII-related antigen and MDM2 were performed. Mitotic count (MC) and MIB-1 based labelling index (LI) were assessed.
Results: Five canine subcutaneous tumours were retrieved. Tumours contained bland spindle cells with sparse eosinophilic cytoplasm, an oval nucleus and an inconspicuous nucleolus, intermixed with ropey collagen and myxoid matrix stained by alcian blue. Three cases contained scattered mature adipocytes (<10%). MC was <1 in four cases and 1 in one case. LI range was 0.9-3.4. All cases expressed vimentin and were S100, SMA, factor VIII-related antigen and MDM2 negative, ruling out peripheral nerve, muscular/myofibroblastic and endothelial cell origin. The low proliferation rate, the absence of lipoblasts and the lack of MDM2 expression ruled out fibrosarcoma, myxoid liposarcoma and dedifferentiated liposarcoma, respectively. A fibroma was ruled out based on the high cellularity.
Conclusions: Histopathological features identified in this caseload (i.e. bland spindle cells, rare adipocytes, ropey collagen and myxoid matrix) paralleled descriptions of SCL in man. The identification of these morphological hallmarks is necessary to diagnose SCL and to avoid a diagnosis of STS characterized by a poorer prognosis
Linfoma multicentrico nella specie canina – Parte 1°: approccio clinico, Parte 2°: approccio terapeutico.
No full textCanine cutaneous perivascular wall tumors at first presentation: clinical behavior and prognostic factors in 55 cases.
Full text linkBACKGROUND: Canine cutaneous perivascular wall tumors (c-PWT) are soft tissue sarcomas recently identified when hemangiopericytomas were reclassified. No previous clinical data are available for c-PWT. HYPOTHESIS/OBJECTIVES: To define the clinical behavior and prognostic role of clinical and pathological variables in a homogeneous population of c-PWT. ANIMALS: Fifty-five c-PWT in 53 client-owned dogs at first presentation undergoing surgery. METHODS: Retrospective case series. The endpoint was the relapse of tumor (local and/or distant). The prognostic values of clinical (age, sex, weight, site and tumor size, adjuvant therapy) and pathological (status of surgical margins, histological grade, mitosis, percentage of tumor necrosis) variables were investigated by univariate and bivariate analyses (P < .05). The pattern of associations between variables was explored by multivariate correspondence analysis (MCA). RESULTS: Twelve dogs had a relapse. Ten dogs had local recurrence, 1 had metastatic disease, and 1 had both. The estimated probability of local recurrence was 0.02, 0.08, 0.20, and 0.24 at 6 months, 1, 2, and 3 years, respectively. Size of the tumor was a significant prognostic factor while status of margins had only a clinically relevant hazard ratio. In MCA evaluation, young age, tumor size (< 5 cm), grade I, and location in the extremities were associated. Association was also observed for older age, tumor size (> 5 cm), grade II, and other location. CONCLUSION AND CLINICAL IMPORTANCE: C-PWT tend to locally recur a long time after surgery. An early diagnosis of c-PWT associated with small tumor size (< 5 cm) and clean surgical margins ensures a good prognosis independently of histological grade
Acute megakaryoblastic leukemia in dogs: a report of three cases and review of the literature.
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Kaplan-Meier Curves, Cox Model, and P-Values Are Not Enough for the Prognostic Evaluation of Tumor Markers: Statistical Suggestions for a More Comprehensive Approach
Full text linkThe assessment of prognostic markers is key to the improvement of therapeutic strategies for cancer patients. Some promising markers may fail to be applied in clinical practice, or some useless markers may be applied, because of misleading results ensuing from inadequate planning of the study and/or from an oversimplified statistical analysis. This commentary illustrates and discusses the main issues involved in planning an effective clinical study and the subsequent statistical analysis for the prognostic evaluation of a cancer marker. Another aim is to extend the most applied statistical models (ie, those using Kaplan-Meier and Cox) to enable the choice of the best-suited methods for study endpoints. Specifically, for tumor-centered endpoints like tumor recurrence, the issue of competing risks is highlighted. For markers measured on a continuous numerical scale, a loss of relevant prognostic information may occur by setting arbitrary cutoffs; thus, the methods to analyze the original scale are explained. Furthermore, because the P-value is not a sufficient criterion to assess the usefulness of a marker in clinical practice, measures for evaluating the ability of the marker to discriminate between “good” and “bad” prognoses are illustrated. Several tumor markers are considered both in human and veterinary medicine. Given the similarity between markers for human breast cancer and canine mammary cancer, an application of the statistical methods discussed within the article to a public dataset from human breast cancer patients is shown
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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