bromochloroacetic-acid and Swine-Diseases

Renal mixed tumor characterized by the absence of nephrogenic blastema and the presence of predominant osteoid-producing osteoblast-like cells occurred in the kidney of a 6-month-old, hybrid, female pig. At the post-mortem examination, the tumor was found as a calcified grayish-white mass at the cranial end of the left kidney. Histologically the tumor consisted of 3 growth areas of poorly differentiated spindle cells, osteoid-producing osteoblast-like cells, and luminal epithelial cells. Transition from the spindle cells to the osteoblast-like cells or the luminal epithelial cells was observed. Immunohistochemically, the spindle cells and the osteoblast-like cells were consistently positive for β-catenin. Although the luminal epithelial cells and adjacent spindle cells were positive for cytokeratin, these 3 types of tumor cells were consistently negative for WT1. The tumor was diagnosed as primary renal mixed tumor characterized by marked proliferation of osteoblast-like cells with osteoid formation.

Topics: Animals; beta Catenin; Cell Proliferation; Epithelial Cells; Female; Immunohistochemistry; Keratins; Kidney Neoplasms; Mixed Tumor, Malignant; Osteoblasts; Swine; Swine Diseases

A 10-year-old, female, pot-bellied pig (Sus scrofa) experienced a 3-month history of reduced appetite, dysphagia, and weight loss. Clinical examination revealed a mass in the left part of the oral cavity extending from the hard to the soft palate. At necropsy, a firm, white, poorly demarcated ulcerated mass at the left hard and soft palate with metastases to the left retropharyngeal lymph node and the lung was observed. Additional findings included a uterine adenocarcinoma, a hepatocellular adenoma, and nodular hyperplasias in spleen and adrenal glands. Histologically, the poorly demarcated, infiltrative growing oral mass consisted of islands, cords, and single epithelial cells with moderate squamous differentiation. Cells were strongly positive for cytokeratin by immunohistochemistry. Similar cells were found in the left retropharyngeal lymph node and the lung. The present findings represent the first report of a metastasizing oral squamous cell carcinoma in a pig.

Topics: Animals; Carcinoma, Squamous Cell; Fatal Outcome; Female; Immunohistochemistry; Keratins; Mouth Neoplasms; Neoplasm Metastasis; Sus scrofa; Swine; Swine Diseases

From 40 pigs rejected for human consumption at slaughter due to an apparent presence of pyemic lung lesions (defined as disseminated processes containing pus and/or necrotic material), the lungs, spleen, liver, and kidneys were subjected to an extended macroscopic examination. Several lung lesions were sampled from each animal for histological and bacteriological examination. Samples from the kidneys and spleens were also subjected to bacteriological examination. At gross level, four groups of lung lesions were identified: 1) disseminated foci with contents of pus and/or necrotic material (n=26); 2) disseminated or multifocally located ecchymoses with a central area of fibroplasia (n=9); 3) non-pneumonic lesions, i.e., disseminated areas of atelectasis (n=1) or haemorrhagic areas developing due to the process of slaughter (n=1); and 4) suppurative lesions without a disseminated distribution pattern (n=3). Histologically, the disseminated suppurative/necrotic foci were identified as: A) abscesses (n=10); B) necrotic lesions (n=6); and C) ectatic or ectatic-like bronchioles with contents of pus and necrotic material (n=10). The macroscopic observation of disseminated centres of fibroplasia with peripheral ecchymoses (n=9) was confirmed histopathologically. The livers of five pigs contained multiple areas of chronic interstitial fibrosis related to migration of Ascaris suum larvae ("milk spotted liver"). Such hepatic lesions were significantly (p<0.01) related to the simultaneous occurrence of disseminated pulmonary ecchymoses with a central area of fibroplasia. Generally, all lung lesions of each individual animal contained identical monocultures of bacteria following this pattern: Staphylococcus aureus (abscesses); Actinomyces hyovaginalis (necroses); S. aureus, A. hyovaginalis, and Arcanobacterium pyogenes (ectatic and ectatic-like bronchioles). Areas with fibrosis were sterile or contained bacteria considered to be a result of contamination. Apart from one kidney, from which S. aureus was cultured, all other organs were sterile. It is concluded that difficulties exist in differentiating pulmonary pyemic lesions from non-pyemic lesions at the gross level. Thus, it was not possible to distinguish between abscesses/necroses and ectatic bronchioles, the pathogenesis of the latter being uncertain. However, the chronic non-pyemic lesions related to the migration of A. suum larvae should be identified by the absence of pus/necrosis. S. aureus was predominantly

Topics: Abscess; Actinomyces; Actinomycosis; Animals; Keratins; Lung; Lung Diseases; Necrosis; Pneumonia, Bacterial; Suppuration; Sus scrofa; Swine Diseases

The immunophenotype of tumor cells and inflammatory infiltrate associated with cutaneous melanocytic lesions (29 melanocytomas, two malignant melanomas, and 23 residual lesions) from 54 adult Iberian and Iberian x Duroc pigs were examined using a panel of nine antibodies. All neoplastic cells were vimentin+, cytokeratin-, and alpha-1-antitrypsin- and the majority were S100+, whereas all pigmented macrophages were vimentin+, cytokeratin-, and S100- and most expressed alpha-1-antitrypsin. Regressing tumors were characterized by zones with low density of neoplastic cells accompanied by heavy infiltration of CD3+ T lymphocytes, whereas zones with high density of neoplastic cells showed very low numbers of CD3+ T lymphocytes. The infiltrate of CD79a+ B cells and IgG, IgM, and IgA plasma cells was low. The majority of lymphocytes of the peri- and intratumoral infiltrate were major histocompatibility complex class II+, but neoplastic cells did not express class II antigen. The 17 residual lesions examined were composed of macrophages containing abundant melanin pigment and low to moderate numbers of CD3+ T lymphocytes. The results of the present study suggest that the local cellular immune response plays a crucial role in the host response that induces regression of cutaneous melanomas and melanocytomas of the Iberian and crossbred Iberian x Duroc pigs.

Topics: alpha 1-Antitrypsin; Animals; Antigens, CD; B-Lymphocytes; CD3 Complex; CD79 Antigens; Histocompatibility Antigens Class II; Immunohistochemistry; Keratins; Melanocytes; Melanoma; Neoplasm Regression, Spontaneous; Plasma Cells; Receptors, Antigen, B-Cell; S100 Proteins; Skin Neoplasms; Swine; Swine Diseases; T-Lymphocytes; Vimentin

A plexiform schwannoma (PFS) observed as a solitary mass in the dermis of a 6-month-old pig consisted of schwannoma cells of Antoni A type and B type. Neoplastic cells in Antoni A type areas sometimes showed cord-like outgrowths or a neurofibromatous pattern. Neoplastic cells in Antoni B type areas showed erythrophagocytosis, some encircling the microvasculature. Immunohistochemically, neoplastic cells were strongly positive for S-100 protein and vimentin. Peripheral parts of the nodules were cytokeratin (clone AE1/AE3)-positive, as in normal swine perineurial cells. Double immunostaining clearly demonstrated neoplastic cells doubly positive for both S-100 protein and cytokeratin, suggesting that S-100-positive Schwann cells and cytokeratin-positive perineurial cells are functional variants of the same cell type. Ultrastructurally, neoplastic cells in Antoni A type areas possessed characteristics of Schwann cells, such as cytoplasmic interdigitation, external laminae and intercellular junctions. At the periphery of the nodules, features of perineurial cells were detected. Neoplastic cells in Antoni B type areas seemed to be undergoing degenerative processes similar to those in Antoni A type regions and they contained many lysosomes. The neoplasm was generally similar in both location and histology to that seen in man, but there were some histological, immunohistochemical and ultrastructural differences. This is the first reported case of PFS in domestic animals.

Topics: Animals; Epidermis; Female; Immunohistochemistry; Keratins; Neurilemmoma; S100 Proteins; Skin Neoplasms; Swine; Swine Diseases; Vimentin

The origin of pulmonary multinucleate giant cells (MGC) in porcine dermatosis vegetans was studied in six Norwegian Landrace pigs ages 4 (male), 5 (female), 6 (female), 10 (female), and 12 (one male, one female) weeks, using an avidin biotin peroxidase and alkaline phosphatase complex immunohistochemical method on sections of formalin- and ethanol-fixed and frozen tissue specimens. Well-characterized, commercially available antisera/monoclonal antibodies to keratin, vimentin, lysozyme, a monocytic antigen, and a myelomonocytic antigen were used. The immunoreactivity to intermediate-sized filaments in MGC was negative for keratins and positive for vimentin. In addition, a positive reaction was found in alveolar macrophages, chondrocytes, fibrocytes, alveolar lymphocytes, and granulocytes in ethanol-fixed tissue. Marked masking was observed in formalin-fixed tissue. Antilysozyme antiserum gave a positive cytoplasmic reaction in alveolar macrophages and MGC, although the reaction was variable in ethanol-fixed tissue. In trypsinized formalin-fixed tissue, a moderate and more consistent cytoplasmic reaction was observed in alveolar macrophages and MGC. Two monoclonal antibodies that identify human cells of the MMS, EMB 11 and Mac 387, were negative for EMB 11 in ethanol-fixed and frozen sections, whereas Mac 387 showed a positive and specific cytoplasmic immunoreaction in alveolar macrophages and small MGC in ethanol- and formalin-fixed tissue. Pulmonary MGC in dermatosis vegetans are derived from mesenchymal cells, and substantial evidence is provided in support of a monocyte/macrophage origin based on a positive reaction for lysozyme and a myelomonocytic antigen. The importance of adequate fixatives for immunohistochemical demonstration of cell-specific markers is clearly shown.

Topics: Animals; Ethanol; Female; Formaldehyde; Giant Cells; Keratins; Lung; Macrophages, Alveolar; Male; Muramidase; Swine; Swine Diseases; Tissue Fixation; Vimentin

Mammary adenocarcinoma was diagnosed in a 3-year-old Landrace sow with prolonged infertility, anorexia and progressive emaciation after parturition. Gross examination confirmed a large tumour in the left anterior mammary gland with metastatic nodules on the pleura and in the parenchyma of lung. Microscopically, the tumour consisted mainly of solid adenomatous proliferations with numerous mitotic figures. Irregular glandular structures, solid nests of polygonal tumour cells without polarity and nests consisting of glandular, cribriform and solid portions were evident in dense fibrous stroma. Immunostaining revealed keratin in the tumour cells.

Topics: Animals; Carcinoma; Female; Immunohistochemistry; Keratins; Lung Neoplasms; Mammary Neoplasms, Animal; Swine; Swine Diseases

Topics: Animals; Brazil; Female; Gastric Mucosa; Keratins; Male; Stomach Ulcer; Swine; Swine Diseases