Cerebral high-grade astrocytoma (glioblastoma) in a cat

A cerebral tumour was found in the right frontal lobe of a 7-year-old female mongrel cat. The mass showed infiltrative growth and caused deformation of the corpus callosum. Histopathologically, the tumour cells showed anaplasia, pleomorphism and mitotic figures. Necrosis and vascular proliferation were prominent. The neoplastic cells surrounded areas of necrosis, but as an indistinct pseudopalisade formation. Immunohistochemically, low numbers of tumour cells labelled positively for anti-glial fibrillary acidic protein and anti-S100 protein. Electron microscopically, the majority of tumour cells had no filaments and cytoplasmic processes, but the differentiated cells presented cytoplasmic filaments and glycogen granules. Based on these findings, the tumour was diagnosed as cerebral high-grade astrocytoma, glioblastoma.     

Malignant lymphoma in nasal cavity and paranasal sinuses of a dog

A case of a canine large cell type T-cell lymphoma, with features of high-grade malignancy is described. The tumour was found confined in the nasal cavity and the paranasal sinuses of a crossbred German Shepherd dog. Histological examination revealed the features of a highly malignant large cell lymphoma. Ultrastructurally, the lymphoid tumour cells bore cytoplasmic protrusions that interdigitated tightly. From a panel of tumour markers used, the neoplastic cells were stained only for vimentin. Immunophenotyping of the tumour cells by means of CD3, CD79, kappa-light chains and lambda-light chains detection was undertaken. The tumour stained only for CD3 and was classified as T-cell lymphoma.     

Osteoclast-like giant cell tumour arising from the kidney in a dog

In this study, a case of osteoclast-like giant cell tumour arising from the kidney is reported in an eight-year-old female Anatolian Shepherd dog. Macroscopically, the tumorous mass covered the hilus of the left kidney. It was 26 x 22 x 12 cm in size and 3700 g in weight. Metastatic tumorous nodules, 0.5-2.0 cm in diameter, were found on the abdominal side of the diaphragm and in the lungs. Microscopically, numerous large osteoclast-like multinucleated giant cells and spindle-spheroidal-shaped cells were seen. Osteoblastic differentiation and osteoid matrix were noted in a few areas at the periphery of the tumour, near the connective tissue septa. The stroma of the tumour tissue was vascular, oedematous and loose. By immunoperoxidase staining, tumour cells showed immunoreactivity for vimentin but not for keratin and desmin, indicating that the tumour had mesenchymal origin. This is the first report in the literature on a malignant osteoclast-like giant cell tumour arising from a visceral organ in animals.     

Bilateral Testicular Leydig Cells Tumour in a Donkey

A rare case of a bilateral Leydig cells tumour located in the testis of a 15-year-old donkey slaughtered normally is presented. Histologically, the testicular tumour showed neoplastic Leydig cells arranged in solid growth as a pseudoadenomatous packet type. To our knowledge, this is the first bilateral Leydig cells tumour, a neoplasm never reported in the donkey.     

Histopathologic and Immunohistochemical Exam in One Case of Canine Endometrial Adenocarcinoma

Canine endometrial carcinomas are rare, and mostly occur in geriatric bitches. In this work, the uterus of a 10‐year‐old female Boxer evidencing an endometrial carcinoma on the body of the uterus was used to describe the histopathological features of the tumour and to study its immunophenotype. In this work, a panel of immunomarkers (cytokeratins AE1/AE3 and 14, vimentin, CD10 and Ki‐67) was applied to the endometrial carcinoma to establish the staining patterns indicative of the tumour agressiveness and cellular differentiation. Additionally DNA ploidy was also performed. In this case, the tumour showed papillar pattern, with large pleomorphic, anaplastic cells and also some aberrant multinucleated and giant cells. In some areas of the tumour, it was also observed cytotrophoblastic‐like cells outlining the papillae. Cytokeratin AE1/AE3 expression was detected in the luminal neoplasic cells. Cytokeratin 14 positivity was sporadic and irregular, and was observed mainly in the luminal epithelium. Only stromal and aberrant cells showed a positive staining to vimentin. Positive membranous staining to CD10 was evidenced by clear epithelial, cytotrophoblastic‐like cells at the tumour surface but not by the stromal cells. The mitotic and Ki‐67 indices were low, suggestive of a weak aggressiveness of the tumour. The multinucleated and giant cells evidenced a positive immunostaining to CK AE1/AE3, and CD 10; its positivity to vimentin was sporadic. This study aims to contribute to the advancement of the knowledge in canine endometrial carcinoma immunophenotype.     

Implantation of Rous sarcoma virus transformed cells in the hamster: effect of various parameters

The effect of inoculation of allogeneic hamster cells transformed by Rous sarcoma virus on tumour growth, in the hamster is described. Inoculation of low doses (10(2)-10(4)) of live cells was followed by the apparition and the growth of sub-cutaneous sarcomas. Repeated injections of irradiated or glutaraldehyde-treated cells which induce immune reactions led only to partial protection since they did not totally prevent tumour growth, after challenge with strong doses (5 X 10(4)) of live transformed cells. Inoculation route did not influence tumour growth, whatever the nature of injected cells. The interest of using irradiated or glutaraldehyde-treated transformed cells in tumour immunity should be emphasised.     

Tumour necrosis factor stimulated gene 6 intrinsically regulates PD-L1 expressions in breast cancer cells,leading to modulation of tumour microenvironment

Recent studies have shown that tumour cells express tumour necrosis factor-inducible gene 6 (TSG-6) and its protein, which is known to play a key role in regulating excessive immune responses and proliferation and growth of mesenchymal stem cells (MSCs). It has not been confirmed whether the inhibition of TSG-6 for tumour cells can suppress tumour cell growth and regulate the activation of immune cells in the tumour microenvironment (TME). TSG-6-specific small interfering RNA was transfected into canine and human breast cancer cells (CIPp, CIPm and BT-20). TSG-6-down-regulated (siTSG-6) cells showed decreased cell proliferation, migration, and invasion abilities. Decreased mRNA expressions of NF-κB, STAT3 and Sox2, confirming that TSG-6 is an upper factor governing tumour growth and metastasis. Notably, siTSG-6 cells showed significantly decreased expression levels of CD44 and PD-L1. Direct and indirect co-culture of canine peripheral blood mononuclear cells (cPBMCs) and the siTSG-6 cells showed significant activation in M1 type macrophages and cytotoxic T cells. They also showed a tendency to decrease in the expression of CTLA-4 and increase in the expression of PD-1. In conclusion, this study suggests that the down-regulation of TSG-6 in breast cancer cells could not only suppress tumour growth and metastasis, and but also regulate TME. Since modulation of immune checkpoint proteins occurs in both tumour cells and immune cells, inhibiting TSG-6 and its protein within the TME could be novel therapeutic target for anticancer treatment.     

Histopathological and immunohistochemical characteristics of two canine lipid-rich mammary carcinomas

Clinicopathological and immunohistochemical findings of two uncommon canine lipid-rich mammary carcinomas are described. The predominant histological feature in both tumours was the presence of at least 80% of cells with intracytoplasmic vacuoles which stained positively with Sudan IV but not with alcian-blue periodic acid-schiff method. In both tumours, small groups of non-vacuolated cells were identified among the vacuolated cells. However, histological and immunohistochemical differences were also found between these tumours. Thus, one of them was composed of tumour cells with a large and single vacuole, which were arranged in lobular pattern, while the other neoplasm showed an intraductal growth of tumour cells with a fine vacuolated cytoplasm. Immunohistochemically, in the first tumour most vacuolated cells were positive for CK (cytokeratin)8-7, indicating a secretory epithelial immunophenotype while CK5 and CK8-7-expressing non-vacuolated cells were associated with luminal duct immunophenotype. However, in the second tumour the expression of CK14 in most of vacuolated cells and alpha-smooth muscle actin (alpha-SMA) in non-vacuolated cells, alone or in combination with CK5 suggested a myoepithelial immunophenotype for both cell types. These results suggest heterogeneity of the cell type and growth pattern for this type of canine tumour as has been described in women but not in dogs.     

Further Field Experiments on the Use of Coccidiostatic Drugs in Unweaned Lambs

A small tumour was found at the periphery of the lung during routine necropsy of a 13-year-old Romney ewe. The tumour consisted of vacuolated, cuboidal cells which lined alveolar spaces without destroying them. Electron microscopy revealed numerous microvilli on the free surface of the cells and irregularly shaped osmiophilic inclusions within the vacuoles. No viral particles were found and the tumour was diagnosed as a well differentiated Type II pneumocyte adenocarcinoma of unknown aetiology.     

An ovine pulmonary tumour of alveolar epithelial Type II cells

A small tumour was found at the periphery of the lung during routine necropsy of a 13-year-old Romney ewe. The tumour consisted of vacuolated, cuboidal cells which lined alveolar spaces without destroying them. Electron microscopy revealed numerous microvilli on the free surface of the cells and irregularly shaped osmiophilic inclusions within the vacuoles. No viral particles were found and the tumour was diagnosed as a well differentiated Type II pneumocyte adenocarcinoma of unknown aetiology.     

Cancer stem cell populations in lymphoma in dogs and impact of cytotoxic chemotherapy

Cancer relapse following chemotherapy has been attributed in part to the presence of cancer stem cells (CSC), which drive tumour growth and metastasis and are highly resistant to the effects of cytotoxic chemotherapy. As a result, treatment with cytotoxic chemotherapy selects for drug‐resistant CSC populations that eventually drive tumour recurrence. Little is known currently regarding the role of CSC in dogs with lymphoma, nor the impact of chemotherapy on CSC populations. Therefore, we prospectively quantitated CSC populations in dogs with B‐cell (BCL) and T‐cell lymphoma (TCL), using tumour aspirates and flow cytometric analysis with a panel of CSC markers. In addition, in vitro studies were carried out to determine the impact of chemotherapy resistance on the stem cell phenotype and stem cell properties of lymphoma cells. We found that the percentages of tumour cells expressing CSC markers were significantly increased in dogs with BCL, compared with B cells from normal lymph nodes. Similar findings were observed in dogs with TCL. In vitro studies revealed that lymphoma cells selected for resistance to CHOP chemotherapy had significantly upregulated expression of CSC markers, formed spheroids in culture more readily, and expressed significantly greater aldehyde dehydrogenase activity compared with chemotherapy‐sensitive tumour cells. Similar results were observed in tumour samples dogs with relapsed BCL. These findings suggest that cytotoxic chemotherapy can lead to a relative enrichment of tumour cells with CSC properties, which may be associated with lymphoma recurrence.     

First report of a malignant collision skin tumour with malignant melanoma and anaplastic sarcoma components in a dog

This paper describes the occurrence of a rare skin tumour that has been removed surgically from the upper lip of a 13-year-old Tibetan spaniel. The tumour was 0.5 cm in diameter and macroscopically appeared as a single dermal mass, but histopathological analysis identified it as a biphasic collision mixed tumour. In the anatomically uniform tumour, 70% (4 mm in diameter) of the total parenchyma was formed by a high-grade sarcoma (with the presence of giant cells), and about 30% of it (1 mm in diameter) was a malignant melanoma (again with the presence of giant cells). The histologically distinct, but anatomically uniform tumour parts were separated by a macroscopically invisible, non-neoplastic epithelial process originating from the overlying hyperplastic epidermis. The two malignant components did not infiltrate the peritumoural vessels and each other's substance. In the sarcoma part, the mitotic and apoptotic indexes were 32 and 8, respectively, whereas in the melanoma part the same parameters were 10 and 6, respectively. During the immunohistochemical investigations anti-α-SMA, anticytokeratin AE1-AE3, anti-Melan-A, anti-Ki-67 and anti-claudin-5 antibodies were applied. In conclusion, this is the first report of a primary cutaneous malignant biphasic collision mixed tumour formed by an anaplastic sarcoma with giant cells and a malignant melanoma.     

Establishment of a cell line (MCM-B2) from a benign mixed tumour of canine mammary gland

A cell line was established from a benign mixed tumour of the canine mammary gland. Light microscopy of the cells cultured on plastic dishes revealed monolayer colonies. Cells that grew within the collagen gel matrix formed large three-dimensional colonies with a branching pattern. Immunohistochemically, these cells reacted intensely with anti-vimentin antiserum and mildly with anti-desmin antiserum. Ultrastructural examination revealed a large nucleus, intracytoplasmic organelles and intermediate filaments, which varied among cells. The cells possessed an abnormal chromosome number, an average of 80 per cell. Histologically, the xenografted tumour of cultured cells was similar to anaplastic carcinoma and reacted strongly with antivimentin antiserum, mildly with anti-desmin antiserum, and weakly with anti-keratin antiserum. The average chromosome number of cells form the xenografted tumour was the same as that of the original cultured cells. These findings suggest that the cell line might be derived from stem cells or atypical cells, and that it should be useful as a model for the study of cell differentiation and proliferation in canine mammary tumours.     

Leiomyosarcoma of the kidney in a dog

A leiomyosarcoma that occurred in the right kidney of a dog (7-year-old female Labrador retriever) was studied pathologically. On histological examination, tumour cells were spindle-shaped, the cell density was high, and complex fasciculated tumour cells showing longitudinal and transverse cross-sections were observed. Both ends of the nuclei were rounded, the nucleoli were clear and many images of nuclear division were observed. Immunohistochemically, tumour cells reacted intensely with anti-vimentin antibody and anti-actin smooth muscle antibody, and mildly with anti-desmin antibody. On electron microscopy, the nuclei of tumour cells were rounded at both ends and elongated elliptically, and a large number of microfibrils with focal density and dense patches were observed in the cytoplasm. This is a case report of a very rare leiomyosarcoma of the dog kidney.     

Does the tumour microenvironment alter tumorigenesis and clinical response in transmissible venereal tumour in dogs?

The canine transmissible venereal tumour (CTVT) is a transmissible cancer that is spread naturally between dogs, with the ability to develop and evade the immune system, despite strict immune surveillance of the host. Furthermore, molecular signalling between cells of the immune system and the tumour microenvironment appear to influence the behaviour and development of the tumour. Thus, this study aimed to quantify the expression of genes related to the immune system such as IL‐6, IFN‐γ, and TGF‐β, as well as angiogenic factors (VEGF, CXCR4), in CTVT cells in vivo and in vitro (primary culture), correlating with the clinical response of the animals treated with vincristine. As expected, the most prevalent subtype was plasmacytoid cells, although lymphocytic cells were also found, indicating the possibility of polyclonality. When we compared the gene expressions of IFN‐γ and IL‐6, we mostly found low expression, concluding that MHC expression was probably not occurring in tumour cells, and no activation of immune cells to eliminate the tumour. The TGF‐β gene was normal in the majority of animals but demonstrated decreased expression in vincristine resistant animals, leading to the hypothesis that the concentration of tumour‐derived TGF‐β was affecting and even suppressing the real TGF‐β expression, favouring tumour proliferation and progression in these cases. VEGF expression was extremely high, demonstrating its angiogenic role in tumour growth, while CXCR4 was decreased, possibly because of CTVT’s low metastatic potential. Thus, we concluded that the tumour microenvironment, together with the immune system of the host, influences CTVT, presumably altering its tumorigenesis and the animal’s clinical response to treatment.     

Microvascular growth of 7,12-dimethylbenz(α)anthracene-induced adenocarcinomas in rats: histology and scanning electron microscopy of resin casts

Vascular changes at various stages of growth of 7,12‐dimethylbenz(α)anthracene (DMBA)‐induced mammary adenocarcinomas in 22 female Sprague‐Dawley rats were investigated using histology, immunohistochemistry and scanning electron microscopy (SEM) of corrosion casts. In the early stage of tumour growth, capillaries within the neoplasms were thin, with 8–10 μm diameter, and characterized by rows of vascular sprouts representing extensive neovascularization and formation of a high‐density capillary plexus. In the intermediate stage of tumour growth, the growing tumour was multi‐nodular and tumour cells were arranged in a tubulopapillary pattern. Capillaries formed spheroid vascular capsules and were characterized by dilation, to a diameter of 10–80 μm, and blind ends. In the late stage of tumour growth, a remarkable reduction in the number of vascular endothelial growth factor‐positive cells and Ki‐67‐stained nuclei was demonstrated. The tunica media of nutritive arteries displayed a tendency to atrophy. Many arteriovenous anastomoses between the major arteries and the veins were found in regions just before their entry into the tumour. The central regions of the tumour were degenerative and necrotic, and vasculature was confined to surface regions of the tumour, forming a basket‐like configuration around the avascular central regions. Resin leakages representing haemorrhage or oedema and distortions such as flattening, break‐off and strangulations of capillaries were frequently observed, all of which are known as late tumour signs. We concluded that these microvascular alterations might change the homogeneity of tumour perfusion and contribute to necrosis in central portions of the tumour.     

Ulex europaeus agglutinin 1 lectin histochemical staining of dog hepatocellular and bile duct carcinomas

Ulex europaeus agglutinin 1 (UEA-1) lectin-binding is a feature of canine intrahepatic bile duct epithelial cells but not of canine hepatocytes. In tumours diagnosed histologically as cholangiocarcinomas or hepatocellular carcinomas, UEA-1 staining occurred in tumour cells regardless of histological appearance. The division of primary liver carcinomas into different presumed cell types of origin is not reflected by equivalent differentiation of the tumour cells and is not of diagnostic value.     

Glomus tumours in the skin and subcutis of three horses

Three horses presented with variably painful, nonulcerated masses of the head or neck that were diagnosed as glomus tumours. Grossly, they were fleshy, pink to tan masses ranging from 0.4 to 9 cm in diameter, involving either the deep dermis and subcutis or the subcutis and underlying skeletal muscle. Microscopically, neoplastic epithelioid cells were arranged in sheets, cords and packets within lobules. The neoplastic cells frequently abutted and formed nodular bulges into large endothelium-lined vascular spaces, especially around the tumour periphery. Large nerve branches were associated with each tumour. As determined by immunohistochemistry, the neoplastic cells consistently expressed α-smooth muscle actin and vimentin, and some cells in two of the cases expressed desmin. A laminin- or collagen IV-positive basement membrane was demonstrated around individual tumour cells or small groups of cells in all three cases. Morphological features and immunohistochemistry supported the diagnosis of glomus tumour, most consistent with the solid type in humans. Applying a classification system used in humans, two of these tumours met criteria of malignancy (glomangiosarcomas). One horse was euthanized due to complications associated with recurrence and treatment-related necrosis and secondary infection.     

Expression of ABC-Transport Proteins in Canine Mammary Cancer: Consequences for Chemotherapy

Intrinsic or acquired drug resistance is a major barrier for chemotherapy of cancer. Importantly, the presence of ATP-binding cassette, ABC-transport proteins in tumour cells circumvents an intracellular accumulation of chemotherapeutic drugs. In this study, 103 canine mammary tumour probes were investigated for mRNA expression of seven ABC-transporters by RT-PCR. All tumour samples expressed multidrug resistance-associated protein 1 (MRP1) and breast cancer resistance protein (BCRP). MRP7 was detected in 97.1% of tumour probes, MRP3 in 96.1%, Pgp in 92.2%, MRP5 in 85.4% and MRP6 in 64.1%. More of the half of tumour samples (56.1%) expressed all of the examined ABC-transport proteins. Approximately one-third of the tumour samples (32.7%) were lacking in one transporter and only 11.2% possessed from three to five transporters. The canine transporter cBCRP was functionally analysed in stable transfected Madin-Darby canine kidney-II cells using an MTT viability test. cBCRP transfected cells showed a 5.4-fold resistance to 10 μ m doxorubicin. Cell survival in the presence of methotrexate was not affected by cBCRP. In conclusion, absence of efficiency of chemotherapy of canine mammary cancer can be caused by expression of seven various ABC-transport proteins. Because cBCRP is expressed in all examined tumour probes and induces resistance to doxorubicin, the application of doxorubicin for treatment of canine mammary is inappropriate.     

百日鸡J-亚群禽白血病组织病理学与超微病理学研究

利用ELISA试剂盒,对百日鸡的禽白血病抗体和抗原进行了检测。在5个百日鸡父母代鸡群中,1个鸡群的ALV-J抗体阳性率为57.14%,其余鸡群皆为阴性;所有鸡群的ALV-A、B抗体均为阴性;ALV p27抗原除1个鸡群为阴性外,其余鸡群阳性率都较高。在百日鸡的J亚群禽白血病病例中,肝脏、脾脏和肾脏显著肿大,且有弥漫性分布的肿瘤结节;在其他脏器也呈现肿瘤结节。组织病理学观察,发现其脏器等组织中,有一定比例的胞质含红色嗜酸性颗粒的髓细胞样瘤细胞与成淋巴细胞,排列致密呈局灶性生长,正常的组织细胞被挤压或破坏。超微病理观察,在脾脏和法氏囊等组织中均看到病毒颗粒,有囊膜,直径约100nm。部分淋巴细胞核膜、细胞膜水肿或溶解破裂,线粒体和内质网也水肿或池变大、细胞质中出现很多空泡状结构。肿瘤细胞的增多以及细胞内和细胞间的水肿,可能是各脏器严重肿大的主要原因。