Histological and immunohistochemical characterisation of uterine adenocarcinoma in an Asian elephant (Elephas Maximus).

A 56-year-old nulliparous female Asian elephant (Elephas maximus) living at the zoological garden of Naples (Italy), with a clinical history of recurrent colic, was found in agonal state and humane euthanasia was elected. At necropsy the uterine body was moderately increased in size and the lumen was reduced due to a poorly demarcated and infiltrative neoplasm. Furthermore, multiple, whitish, firm nodules were present in both lungs. Histological examination of the uterine mass revealed epithelial cells arranged in tubular or solid pattern infiltrating the endometrium and the muscular layer. Immunohistochemical examination showed immunoreactivity of neoplastic cells to oestrogen receptors antibody. Pulmonary lesions were histologically and immunohistochemically superimposable to the epithelial uterine neoplasm. A definitive diagnosis of uterine adenocarcinoma with pulmonary metastases was made.

The occurrence and pathogenicity of Serratospiculum tendo (Nematoda: Diplotriaenoidea) in birds of prey from southern Italy.

The air sacs of free-ranging birds of prey (n= 652) from southern Italy, including 11 species of Accipitriformes and six of Falconiforms, were examined for infections with Serratospiculum tendo (Nematoda: Diplotriaenoidea). Of the 17 species of birds examined, 25 of 31 (80.6%) peregrine falcons (Falco peregrinus) from Calabria Region and a single northern goshawk (Accipiter gentilis) from Campania Region were infected with S. tendo, suggesting a strong host specificity for the peregrine falcon. The northern goshawk and 18 of 25 infected peregrine falcons showed cachexia and all infected birds had bone fractures. At gross examination, air sacculitis and pneumonia were the most common lesions in infected birds. Microscopically, the air-sac walls showed thickening of the smooth muscle cells, resulting in a papillary appearance, along with hyperplasia of the mesothelium and epithelium, and foci of plasma cell infiltration and macrophages associated with several embryonated eggs and adult parasites. Extensive areas of inflammation were found in the lungs, characterized by lymphocytes, macrophages and fibroblasts surrounding embryonated eggs. The northern goshawk also had detachment of the dextral lung with several necrotic foci. In this case, the death of the bird was directly attributed to S. tendo infection. Lesions and pathological changes observed here suggest that S. tendo can cause disease.

An unusual case of intestinal leiomyositis in a Bernese mountain dog.

A 1-year-old, female Bernese mountain dog was presented to the Veterinary Teaching Hospital of Turin University with a 3-month history of weight loss, intermittent anorexia, vomiting, constipation, and abdominal distension. Full-thickness biopsies from the stomach, duodenum, jejunum and ileum were collected for histological and immunohistochemical examination. Microscopic lesions displayed severe diffuse degeneration and loss of leiomyocytes, with lymphocytic leiomyositis, fibroplasia, angiogenesis, severe diffuse neuronal atrophy, and ganglioneuritis in the myenteric (Auerbach's) plexus. A diagnosis of chronic idiopatic intestinal pseudo-obstruction was made. Response to immunosuppressive therapy was poor and the dog was humanely euthanized. Unique findings were mononuclear infiltration composed predominantly of B-cell, angiogenesis and weak immunoreactivity for neuron-specific enolase.

Clinical significance and in vitro cellular regulation of hypoxia mimicry on HIF-1α and downstream genes in canine appendicular osteosarcoma.

Cellular adaptation to a hypoxic microenvironment is essential for tumour progression and is largely mediated by HIF-1α and hypoxia-regulated factors, including CXCR4, VEGF-A and GLUT-1. In human osteosarcoma, hypoxia is associated with resistance to chemotherapy as well as with metastasis and poor survival, whereas little is known about its role in canine osteosarcoma (cOSA). This study aimed primarily to evaluate the prognostic value of several known hypoxic markers in cOSA. Immunohistochemical analysis for HIF-1α, CXCR4, VEGF-A and GLUT-1 was performed on 56 appendicular OSA samples; correlations with clinicopathological features and outcome was investigated. The second aim was to investigate the in vitro regulation of markers under chemically induced hypoxia (CoCl2). Two primary canine osteosarcoma cell lines were selected, and Western blotting, immunofluorescence and qRT-PCR were used to study protein and gene expression. Dogs with high-grade OSA (35.7%) were more susceptible to the development of metastases (P = 0.047) and showed high HIF-1α protein expression (P = 0.007). Moreover, HIF-1α overexpression (56%) was correlated with a shorter disease-free interval (DFI; P = 0.01), indicating that it is a reliable negative prognostic marker. The in vitro experiments identified an accumulation of HIF-1α in cOSA cells after chemically induced hypoxia, leading to a significant increase in GLUT-1 transcript (P = 0.02). HIF-1α might be a promising prognostic marker, highlighting opportunities for the use of therapeutic strategies targeting the hypoxic microenvironment in cOSA. These results reinforce the role of the dog as a comparative animal model since similar hypoxic mechanisms are reported in human osteosarcoma.

Evaluation of leukocyte counts and neutrophil-to-lymphocyte ratio as predictors of local recurrence of feline injection site sarcoma after curative intent surgery.

Local recurrence (LR) is the major concern in the treatment of feline injection-site sarcoma (FISS). Pretreatment leukocyte counts and ratios have been reported as diagnostic and/or prognostic markers in human and canine oncology. The aim of this retrospective study was to explore the prognostic impact on LR and overall survival time (OST) of pretreatment neutrophil-to-lymphocyte ratio (NLR), white blood cell count (WBCC), neutrophil count (NC) and lymphocyte count (LC) in cats with surgically excised FISS. Eighty-two cats with histologically confirmed FISS at first presentation, without distant metastases, and with available pretreatment haematological analyses were retrospectively enrolled. The correlation of NLR, WBCC, NC, LC with tumour variables and patient variables was explored. NLR was correlated with tumour size (P = .004), histological pattern of tumour growth (P = .024) and histotype (P = .029), while WBCC and NC were associated with ulceration (P = .007, P = .011) and pattern of growth (P = .028, P = .004). No significant relationships emerged between LC and any of the considered variables. The impact of NLR, WBCC, NC, LC on LR and OST was then estimated in univariate and multivariate analysis. In univariate analysis, NLR, WBCC and NC were significant prognostic factors for both LR and OST. NLR, WBCC and NC remained prognostic in multivariate analysis for LR but not for OST. When NLR, WBCC and NC were jointly analysed, WBCC was the marker with the greater impact on LR. Preoperative NLR, WBCC and NC may aid in identifying cats at higher risk of LR.

Canine oral fibrosarcoma: Changes in prognosis over the last 30 years?

Canine oral fibrosarcoma (oFSA) is a malignant, infiltrating, mesenchymal tumour affecting the oral cavity primarily of medium to large middle aged dogs. The diagnosis often is made late in the course of the disease, due to the frequent caudal location of the tumour, and histopathology is not always sufficient to discriminate undifferentiated oFSA from other poorly differentiated malignant mesenchymal tumours occurring at the same site, especially in small biopsy samples. The literature exclusively relating to oFSA is limited and outcome data following treatment are difficult to compare. The purpose of this article is to provide an overview of the literature spanning the last 30 years, specifically with regard to different treatment modalities in their relation to prognosis of canine oFSA. Overall, the survival rate for dogs with oFSA has improved in recent years (overall survival 247-743 days, compared to 30-540days in papers published before 2000), probably due to better surgical planning. The major concern in clinical management of canine oFSA is the high local rate of recurrence (up to 57%), whereas metastasis occurs late in about 10-14% of affected dogs. Wide surgical excision is the mainstay of treatment. Initially, the tumour was considered to be radioresistant, but a combination of surgery and radiotherapy seems to be the most promising treatment modality at present. Despite a histopathological diagnosis of a low-grade tumour, an aggressive treatment approach is always warranted to cure oFSA, but the ability to control local disease still represents the major challenge.

Utility of flow cytometry in canine primary cutaneous and matched nodal mast cell tumor.

Mast cell tumors (MCT) are among the most frequent tumors in dogs, but studies regarding canine mast cell immunophenotype are lacking. The aim of this study was to assess the feasibility of flow cytometric analysis of MCTs, to describe canine MCTs immunophenotype(s), and to evaluate the ability of flow cytometry to detect mast cells in lymph node aspirates. Thirty-four primary canine MCTs and 12 draining lymph nodes were evaluated regarding the expression of CD117, IgE, CD11b, CD18, CD44, CD34, CD25 and CD45. Distinct populations attributable to mast cells and eosinophils were recognized based on light scatters and CD117 positivity. Common antigens (CD18, CD45, CD44) and CD117 were detected in all cases; positivity for IgE and CD11b was found in 28 (82%) and 23 (68%) cases respectively, while CD34 and CD25 were occasionally expressed. A single multicolor tube (IgE/CD117/CD11b/CD21/CD5) allowed the identification of mast cells in lymph nodes, showing a high correlation with cytology in quantifying mast cells infiltration. In conclusion, flow cytometric analysis can be applied to characterize canine MCTs and can be used to detect the presence of mast cells in lymph nodes. The immunophenotype abnormalities observed may be useful to confirm the neoplastic nature of such mast cells but the diagnostic usefulness of atypical antigen expression remains to be clarified.

PDGFRs expression in dogs affected by malignant oral melanomas: correlation with prognosis.

Canine malignant melanoma (CMM) is the most common canine oral tumour, and up to 70-75% of dogs in stage II-III die within 1 year after surgery. The purpose of this study was to evaluate the expression of platelet-derived growth factors receptors (PDGFR)-α and -ß in stage II and III CMMs and to correlate it with prognosis. PDGFRs expression was evaluated by immunohistochemistry on 48 cases of formalin-fixed CMM samples and correlated with clinical-pathological findings and outcome after surgery. PDGFRs co-expression was observed in 37.5% of cases. Positivity for PDGFR-α and -ß receptor was present in 54.2 and 47.9% of cases, respectively. Ki67 values >19.5% were ascertained in 66.7% of cases. Statistical analysis showed that PDGFRs co-expression and Ki67 values > 19.5% were both associated with worse prognosis. PDGFRs expression suggests a role in the pathogenesis and progression of CMM, and α and ß co-expression appears to be associated to worse prognosis.

Prolongation of survival of dogs with oral malignant melanoma treated by en bloc surgical resection and adjuvant CSPG4-antigen electrovaccination.

Reported post-surgery 1-year survival rate for oral canine malignant melanoma (cMM) is around 30%; novel treatments are needed as the role of adjuvant chemotherapy is unclear. This prospective study regards adjuvant electrovaccination with human chondroitin sulfate proteoglycan-4 (hCSPG4)-encoded plasmid in 23 dogs with resected II/III-staged CSPG4-positive oral cMM compared with 19 dogs with resected only II/III-staged CSPG4-positive oral cMM. Vaccination resulted in 6-, 12-, 18- and 24-month survival rate of 95.6, 73.9, 47.8 and 30.4%, respectively [median survival time (MST) 684 days, range 78-1694, 8 of 23 dogs alive] and 6-, 12-, 18- and 24-month disease-free interval (DFI) rate of 82.6, 47.8, 26.1 and 17.4%, respectively (DFI 477 days, range 50-1694). Non-vaccinated dogs showed 6-, 12-, 18- and 24-month survival rate of 63.2, 26.3, 15.8 and 5.3%, respectively (MST 200 days, range 75-1507, 1 of 19 dogs alive) and 6-, 12-, 18- and 24-month DFI rate of 52.6, 26.3, 10.5 and 5.3%, respectively (DFI 180 days, range 38-1250). Overall survival and DFI of vaccinated dogs was longer in those <20 kg. In vaccinated and non-vaccinated dogs local recurrence rate was 34.8 and 42%, respectively while lung metastatic rate was 39 and 79%, respectively.

Nuclear morphometry in canine acanthomatous ameloblastomas and squamous cell carcinomas.

The aim of this study was to evaluate whether morphometrical analysis can be of diagnostic value for canine acanthomatous ameloblastoma. We calculated, by means of an automated image analyser, some morphometric nuclear parameters, in particular: mean nuclear area (MNA), mean nuclear perimeter (MNP), maximum and minimum diameters (MDx and MDm) coefficient of variation of the nuclear area (NACV), largest to smallest dimension ratio (LS ratio), and form factor (FF), in 8 canine acanthomatous ameloblastomas, and we compared these morphometric data to those of 13 squamous cell carcinomas of canine gingiva. The results indicated a progressive increase of the MNA, NACV, MNP and MDm proceeding from acanthomatous ameloblastomas (MNA: 42.11+/-8.74; NACV: 28,36+/-7,23; MNP: 24.18+/- 2.68; MDm: 5.69+/-0.49) to squamous cell carcinomas (MNA:49,69+/-9,10; NACV: 30,89+/-7,75; MNP: 25.63+/-2.54; MDm: 6.64+/-0.73). On the contrary, the LS ratio and the FF resulted greater in acanthomatous ameloblastomas (LS ratio: 1,63+/-0,12; FF: 1,13+/-0,002) than in SCCs (LS ratio: 1,40+/-0,12; FF:0.91+/-0.38). Moreover, the MNA, MNP,MDx and MDm resulted similar (MNA: p=0.89; MNP: p=0,65; MDm: p=0,16; MDx: p=0,13) in a subset of four acanthomatous ameloblastomas with cellular atypia (MNA:49,01+/-6,88; MNP: 26,28+/-1,99; MDm: 6.08+/-0.41; MDx: 10.18+/-0.88) and in squamous cell carcinomas (MNA:49.69+/-9,10; MNP: 25.63+/-2.54; MDm: 6.64+/-0.73; MDx: 9.26+/-1.05). While the NACV values resulted higher in typical acanthomatous ameloblastoma (29,99+/-6,06) than in atypical acanthomatous ameloblastoma (26,74+/-8,84) and similar to those of the SCCs (30,89+/-7,75). These results seem to confirm that acanthomatous ameloblastoma is a malignant or potentially malignant lesion and emphasizes that nuclear morphometry analysis can be an useful diagnostic and prognostic method in canine oral pathology.

Immunohistochemical study of STAT3 expression in feline injection-site fibrosarcomas.

STAT3 (signal transducer and activator of transcription 3) is a cytoplasmic transcription factor that plays a role in the G1 to S phase cell-cycle transition and is induced by cytokines and growth factors. In the present study, the relation between histological grade and anti-STAT3 immunoreactivity was evaluated in 39 feline injection-site sarcomas treated surgically, 24 of the cats having received preoperative treatment with doxorubicin. Anti-STAT3 immunoreactivity was significantly lower in cases receiving preoperative doxorubicin, specifically with regard to nuclear localization. Moreover, STAT3 expression (intranuclear) was significantly correlated with mitotic activity in the animals that did not receive doxorubicin (P=0.019), and with differentiation score (P=0.009). STAT3 expression was correlated with the histological grade in both doxorubicin-treated and -untreated cats; in the treated cats, however, this correlation applied only to cytoplasmic STAT3 (P=0.018). Doxorubicin treatment induced a significant decrease in STAT3 expression (nuclear, P<0.0001; cytoplasmic, P=0.033) as compared with cases treated by surgery alone. These findings support existing evidence from human and experimental pathology on the potential role of STAT3 in oncogenesis and tumour progression.

Bovine Papillomavirus Type 13 Expression in the Urothelial Bladder Tumours of Cattle.

Bovine papillomavirus type 13 (BPV-13), a novel Deltapapillomavirus, has been found associated with urothelial tumours of the urinary bladder of cattle grazing on lands infested with bracken fern. BPV-13 was detected in 28 of 39 urothelial tumours. Diagnosis was based on sequencing of L1 and E5 amplicons from tumour samples. The nucleotide sequences generated from these amplicons showed a 100% homology with the sequences of BPV-13 L1 and E5 DNA found in Brazil from a fibropapilloma of the ear in a cow and from equine sarcoids in two horses. GenBank accession number of our representative BPV-13 sequences is JQ798171.1. Furthermore, mRNA encoding BPV-13 E5 oncoprotein was also documented, and its expression was also shown by immunohistochemistry and immunofluorescence in the basal and suprabasal urothelial tumour cells. In twenty-three tumours, BPV-13 was simultaneously found with BPV-2, a Deltapapillomavirus genus, species 4. The latter virus was detected by amplifying and sequencing a 154-bp-sized DNA fragment of BPV-2 E5. In addition, BPV-13 by itself was seen to be expressed in five BPV-2-negative urothelial tumours. This study shows that BPV-13 is present in urothelial tumour cells thus sharing biological properties with BPV-1 and BPV-2. Although further studies are needed, BPV-13 appears to be another worldwide infectious agent responsible for a distressing disease causing severe economic losses in cattle industry.

Retrogenic expression of the MET proto-oncogene correlates with the invasive phenotype of human rhabdomyosarcomas.

The MET oncogene encodes the receptor for HGF/Scatter Factor, known to control cell motility and invasion in epithelial cells. We report that the Met/HGF receptor, absent in differentiated adult skeletal muscles, is aberrantly expressed in clinical samples and in established cell lines of human rhadbomyosarcomas. In both the embryonal and alveolar histotypes the oncogene is overexpressed and, in some cases, amplified. The Met receptor is exposed at the cell surface and is functionally active in response to HGF/Scatter Factor. Accordingly, rhabdomyosarcoma cells exhibit an invasive phenotype in vitro in response to exogenous HGF/Scatter factor. As the factor is known to be produced by connective tissues, a paracrine stimulation of rhabdomyosarcoma invasiveness in vivo is hypothesized. Two alveolar rhabdomyosarcomas were found in co-express the ¿two-kringle' alternatively-spliced HGF/Scatter Factor variant, which has been previously shown to stimulate cell motility and matrix invasion in vitro. These cells displayed the invasive phenotype in the absence of exogenous HGF/Scatter Factor, suggesting an autocrine mechanism in vivo. These data indicate that aberrant expression of the MET proto-oncogene provides rhabdomyosarcoma cells with the same property as embryonal myoblasts to migrate into the surrounding connective tissues.

Expression of endothelin-1 and endothelin-1 receptor A in canine mammary tumours.

Endothelins and their receptors have been implicated in numerous diseases and have recently emerged as relevant players in a variety of malignancies. Tumours overexpress the Endothelin-1 (ET-1) and the Endothelin-A receptors (ETAR) and their interaction enhances tumour growth and metastasis by promoting tumour cell survival, proliferation and angiogenesis. In this study we have evaluated the expression of ET-1 and ETAR in 50 canine mammary tumours, compared to normal controls. Results demonstrated a progressive increase in ET-1 and ETAR expression from benign tumour to grade 1 and to grade 2 malignant mammary tumours with a decrease of expression in grade 3 carcinomas. Co-localization of ET-1 and ETAR was observed in benign mammary tumours and in G1 and G2 carcinomas, while absent in G3 carcinomas. Concluding, ET-1/ETAR can be considered reliable markers for evaluating malignancy of canine mammary tumours and could have importance for the development of specific anticancer therapies.

Modified semitendinosus muscle transposition to repair ventral perineal hernia in 14 dogs.

OBJECTIVES: To describe a modified technique of semitendinosus muscle transposition for the repair of ventral perineal hernia. MATERIALS AND METHODS: Retrospective review of case records of dogs with ventral perineal hernia that were treated by transposing the medial half of the longitudinally split semitendinosus muscle of one limb. The transposition of the internal obturator muscle was used when uni- or bilateral rectal sacculation was also present in addition to ventral perineal hernia; colopexy and vas deferens pexy were also performed. RESULTS: Fourteen dogs were included. In addition to ventral perineal hernia, unilateral and bilateral perineal hernia was also present in five and six of the dogs, respectively. The mean follow-up time was 890 days. Ventral perineal hernia was successfully managed by the modified semitendinosus muscle transposition with minor complications in all the dogs included in the study. CLINICAL SIGNIFICANCE: Despite the small number of dogs included, the unilateral transposition of the medial half of the longitudinally split semitendinosus muscle consistently supported the ventral rectal enlargement in perineal hernia without obvious adverse effects.

MET oncogene aberrant expression in canine osteosarcoma.

The objective of this study was to investigate the role of the MET oncogene in canine osteosarcoma. Seven large-breed dogs affected by spontaneous skeletal osteosarcoma underwent en bloc tumor excision. Total RNA was extracted from frozen tumor samples and assessed for expression of the MET oncogene by Northern blot analysis. Five of seven biopsy samples expressed high levels of the MET oncogene; its expression in the primary tumors was comparable with that previously identified in primary osteosarcomas in humans. A lung metastasis from one of the dogs expressed MET at a higher level than did its primary tumor. Spontaneously arising osteosarcoma in dogs clinically and pathologically mimics the corresponding disease in humans. We previously demonstrated that the MET oncogene was aberrantly expressed in a high percentage of human osteosarcomas. The results of the current study also provide a molecular parallel between the tumors in dogs and humans. This in vivo model may be helpful in evaluating new strategies for therapy against osteosarcoma.

Expression of Major Histocompatibility Complex class I and II in a case of Neospora caninum myositis in a dog.

Neosporosis was diagnosed in a 2-month-old dog by indirect immunofluorescence antibody test (IFAT) and confirmed by means of histopathology and immunohistochemistry. The associated myositis was characterized by Major Histocompatibility Complex expression on some muscle fibres. This finding indicates an immunological activation, of the muscle cells that, acquiring Major Histocompatibility Complex expression, may, in some way, contribute to antigen presentation. A possible role of these glycoproteins in the pathogenesis of Neospora-associated myositis is discussed.

Expression of vascular endothelial growth factor receptor Flk-1 in canine mammary tumours.

Vascular endothelial growth factor (VEGF) induces endothelial cell proliferation, and the beginning of angiogenesis, by interacting with specific endothelial receptors termed VEGFR-1 (Flt-1) and VEGFR-2 (Flk-1). In this study, Flk-1 expression was evaluated immunohistochemically in 10 benign and 40 malignant canine mammary tumours. There was immunolabelling of endothelial cells located within the neoplastic proliferation and at the infiltrating periphery, and also of neoplastic cells. The number of positive endothelial and neoplastic cells, was higher in malignant than in benign tumours. Moreover, in the malignant tumours, expression of Flk-1 increased from well to less differentiated phenotypes (grade 1-3). The presence of VEGF receptor on neoplastic cells suggests that VEGF has an autocrine function in which neoplastic cells act as both VEGF producers and target cells. Thus, in malignant tumours, VEGF may contribute to neoplastic growth by inducing angiogenesis and by stimulating the proliferation of neoplastic cells.

Evaluation of angiogenesis in canine seminomas by quantitative immunohistochemistry.

Angiogenesis, which assists in supplying the nutritional and respiratory needs of proliferating cells, is essential for tumour growth. Angiogenic control is complex, involving a network of cytokines, in particular vascular endothelial growth factor (VEGF), a potent endothelial cell mitogen which also stimulates neoplastic cell proliferation. The purpose of this study was to evaluate VEGF expression and microvessel density (number of microvessels per mm(2)), in canine seminomas. VEGF expression and microvessel density were higher in seminomas than in normal testicular tissue; both parameters were higher in diffuse tumours than in intratubular tumours. These data demonstrate an increase in angiogenesis in the more malignant histological types of seminoma and suggest that both VEGF and microvessel density are useful criteria for evaluating the intrinsic malignancy and growth potential of canine testicular tumours.

Bone allografts and adjuvant cisplatin for the treatment of canine appendicular osteosarcoma in 18 dogs.

The results achieved in 18 dogs following the use of frozen bone cortical allografts for limb-sparing resection of non-metastatic canine appendicular osteosarcoma are presented. Three to five cisplatin doses (70 mg/m2) were administered, starting the day after surgery. The mean and median survival times were 478 and 266 days (range 80 to 2,611 days), respectively. The survival rate was 94 per cent at three months, 78 per cent at six months, 35 per cent at 12 months, 23 per cent at 18 months and 19 per cent at 24 months; the disease-free interval was 80 to 1,246 days (mean 365 days, median 266 days). Lung metastasis developed in 55 per cent of the dogs within one year. Complications were observed in 14/18 dogs (78 per cent), comprising local recurrence (28 per cent), allograft infection (39 per cent) and implant failure (11 per cent). Despite complications, limb sparing is a useful alternative to amputation in selected cases of appendicular osteosarcoma.