Canine mammary carcinomas: influence of histological grade, vascular invasion, proliferation, microvessel density and VEGFR2 expression on lymph node status and survival time.

Spontaneous invasive non-inflammatory canine mammary carcinomas (CMC) and their regional lymph nodes (LN) were analysed (n = 136). Histological grade (HG) and vascular invasion (VI) in the tumours and lymph node status were recorded. Proliferation index (PI), microvessel density (MVD) and vascular endothelial growth factor receptor 2 (VEGFR2) expression were estimated using anti-proliferating cell nuclear antigen (PCNA), anti-von Willebrand factor and anti-Flk-1, respectively. Eighteen months follow-up was performed (34 bitches). Tumours of different grades showed differences regarding PI, Flk-1/integrated optical density (Flk-1/IOD) and MVD. Every feature showed significant association with LN status through bivariate analyses. From multivariate analyses, VI and Flk-1/IOD were selected to predict LN status. Data revealed that the probability of a CMC-bearing bitch to remain alive at 1, 4, 5 and 14-18 months was 0.91, 0.87, 0.81 and 0.77, respectively. Besides LN status, VI was the only feature positively correlated with survival time, although a trend to shorter survival of animal patients bearing high expressing VEGFR2 CMC was noted.

Lack of prognostic significance of angiogenesis in canine melanocytic tumours.

The prognostic significance of angiogenesis in some canine tumours has been investigated, but little is known about its relevance in canine melanocytic tumours (MTs). The aim of this study was to evaluate the prognostic significance of angiogenesis in canine MTs. A total of 36 cutaneous melanocytomas (benign MTs), 40 cutaneous melanomas (malignant MTs) and 43 oral melanomas were studied. Survival data were available for a subset of 59 cases. Microvessel density (MVD) and endothelial area (EA) were determined by immunolabelling using an antibody specific for von Willebrand factor (vWF). Mean MVD (expressed as the number of microvessels per mm(2)) was 129 ± 14 in melanocytomas, 191 ± 16 in cutaneous melanomas and 208 ± 16 in oral melanomas. Mean EA (expressed as the percentage of the total area) was 1.5 ± 0.14 in melanocytomas, 2.6 ± 0.2 in cutaneous melanomas and 2.4 ± 0.3 in oral melanomas. The differences in MVD and EA between melanocytomas and melanomas were significant (P = 0.001 and P = 0.003, respectively). MVD and EA were significantly correlated between cutaneous and oral MTs (r = 0.54; P <0.001 and r = 0.63; P <0.001, respectively). MVD and EA were not related to survival in cutaneous and oral MTs. In conclusion, tumour vascularization was higher in melanomas than in melanocytomas, but it seemed to have no prognostic significance in these tumours.

Primary pulmonary adenocarcinoma metastatic to the uvea, brain and adrenal gland in a dog.

A 10-year-old male Briard dog was presented because of listlessness, abnormal gait, fever, inappetence, and seizures. A non-pigmented growth was observed in the ventral quadrant of the left iris. Thoracic radiographs revealed multiple pulmonary metastases and the owner opted for killing. On necropsy, lung masses and nodules in left iris, right adrenal medulla, and brain were detected. Histologically the primary tumour was diagnosed as pulmonary adenocarcinoma with predominant solid pattern. Metastases to regional lymph nodes, uvea, adrenal medulla, and brain were recognized. The metastatic behaviour resembled that occurring in humans. To the authors' knowledge, this is the first report of a pulmonary adenocarcinoma with metastasis to the uvea in a dog.

Cutaneous lymphangiosarcoma in a young dog: clinical, anatomopathological and lectinhistochemical description.

Lymphangiosarcoma is a rare tumour in domestic animals arising from lymphatic endothelial cells. Occasionally, microscopic differentiation with haemangiosarcoma may be difficult. The aim of the present study was to describe a lymphangiosarcoma in a 1-year-old female Doberman Pinscher dog and to characterize its lectinhistochemical binding pattern as compared with that of haemangiosarcoma. The dog was presented because of a cutaneous painful swelling located in the left axilla. Histological diagnosis confirmed lymphangiosarcoma. The dog was killed. Necropsy revealed mediastinal lymph nodes' involvement. Twenty lectins were tested in tissue sections of this case as well as in four haemangiosarcomas from other dogs. Staining intensity was issued upon optical density determinations. Percentage of lectinhistochemical staining area was also conducted. RCA-I showed the most intense and wide distributed labelling pattern for lymphangiosarcoma. PHA-E was the counterpart for haemangiosarcoma. Should similar results be obtained in further studies, such differences could aid in the differential diagnosis between lymphangiosarcoma and haemangiosarcoma when histological pictures were not conclusive.

Peripheral neuroblastoma in a newborn piglet.

Peripheral neuroblastoma (PNB) is a rare neoplasia derived from neuroepithelial cells. PNB typically presents as a greyish mass, composed of round cells with features of neuronal differentiation. Necropsy, performed on a 1-day-old piglet, revealed a mass craniodorsally located in the abdominal cavity. Histologically, the predominant population consisted of small round to ovoid cells with scanty cytoplasm and dark round nuclei, besides, there were larger neurone-like cells. Neurone-specific enolase and S-100 protein were immunohistochemically detected, while glial fibrillary acidic protein was negative. Histological and immunohistochemical findings substantiated the diagnosis of a grade II peripheral neuroblastoma. This seems to be the first description of a PNB in a newborn piglet.

Glomerular lesions in renal biopsies of Saimiri boliviensis (primate) examined by light and electron microscopy and immunohistochemistry.

In order to determine the existence of glomerular lesions in Saimiri boliviensis, renal biopsies were performed in 20 clinically healthy animals of similar age and both sexes. Biopsies were obtained by laparotomy with a Tru-Cut biopsy needle. Mesangioproliferative glomerulonephritis characterized by an increased number of mesangial cells and increased mesangial matrix was present in 35% of the animals. Proliferative glomerulonephritis characterized by increased numbers of epithelial and endothelial cells with narrowed capillary lumen, and membranous glomerulonephritis characterized by diffuse thickening, wrinkling, and occasional lamellation of basement membranes, were present in 15% of the samples. Ultrastructural features included increased mesangial matrix, fusion of the visceral epithelial foot processes, thickened glomerular basement membranes, and incipient lamellation. Immunohistochemical examination revealed granular deposits of immunoglobulin M in the cytoplasm of mesangial cells and in the mesangial matrix in 50% of the samples.

Intermediate filament expression and lectin histochemical features of canine transmissible venereal tumour.

Immunocharacterization of intermediate filament proteins and lectin-binding studies were carried out in canine transmissible venereal tumour (TVT), a unique neoplasia sharing some epidemiological features with Kaposi's sarcoma in humans. Neoplastic cells express vimentin, but neither cytokeratin nor desmin. Regarding lectins, TVT cells express receptors for Triticum vulgaris (WGA), Concanavalia ensiformis (Con A) and Ricinus communis I (RCA-I). They appear to be negative for Ulex europaeus-I (UEA-I), Arachis hypogaea (PNA), Glycine maximus (SBA) and Dolichos biflorus (DBA).

Double immunoenzymatic labelling of intermediate filaments in bovine urinary bladder tumours.

Double immunoenzymatic labelling made possible the simultaneous staining of two antigens with a mixture of polyclonal and monoclonal commercial antibodies. Immunocharacterization of intermediate filament proteins was found to be an accurate indicator of histogenesis in urinary bladder tumours of cattle.