Proposal of a 2-tier histologic grading system for canine cutaneous mast cell tumors to more accurately predict biological behavior.

Currently, prognostic and therapeutic determinations for canine cutaneous mast cell tumors (MCTs) are primarily based on histologic grade. However, the use of different grading systems by veterinary pathologists and institutional modifications make the prognostic value of histologic grading highly questionable. To evaluate the consistency of microscopic grading among veterinary pathologists and the prognostic significance of the Patnaik grading system, 95 cutaneous MCTs from 95 dogs were graded in a blinded study by 28 veterinary pathologists from 16 institutions.

Mast cells and canine mast cell tumours. A review.

This article reviews the literature on mast cells and tumours derived from mast cells in the dog. Mast cells play a central role in inflammatory and immune reactions. Mast cells, normal and neoplastic, contain and release important biologically active substances: heparin, histamine, eosinophilic chemotactic factor and proteolytic enzymes.

Congenital tumours and tumour-like lesions in domestic animals. 3. Horses. A review.

The literature on congenital tumours and tumour-like lesions in horses was reviewed. Included were embryonic tumours and teratomas. Special attention was paid to the ubiquitous adenomatous hyperplasia of the placenta.

Congenital and hereditary tumours in domestic animals. 2. pigs. A review.

The literature on congenital and hereditary tumours in pigs was reviewed. One hitherto unreported own case was added. Sporadic cases of congenital tumours included several types found in newborn piglets.

Tumours in calves: comparative aspects.

In this paper, calf neoplasia is discussed in relation to a series of cases comprising (1). spontaneous congenital bovine tumours of fetuses and newborn animals, (2). spontaneous juvenile-type tumours in calves aged 2-12 months, and (3).

Progesterone receptors in normal, dysplastic and tumourous feline mammary glands. Comparison with oestrogen receptors status.

The aims of the study were to standardise an immunohistochemical (IHC) method for the detection of progesterone receptors (PR) on formalin-fixed, paraffin wax-embedded tissue sections of feline mammary gland tumours and dysplasias, comparing the results with those obtained using the radiolabelled ligand dextran coated charcoal (DCC) assay applied to frozen tissue samples from the same cases. Also, to define the immunohistochemical distribution of PR in the different cellular compartments of the lesions and to compare the oestrogen receptor (ER) and PR status of the feline mammary lesions. Proliferative mammary lesions collected from 34 cats were studied; 25 malignant tumours and 9 benign tumours and dysplasias.

Congenital tumours and tumour-like lesions in domestic animals. 1. Cattle. A review.

The literature on congenital tumours and tumour-like lesions in calves was reviewed. Lesions were subdivided by their anatomical distribution and in addition also according to their histologic-pathogenetic nature. As a result of the latter method, four main groups were formed covering most of the lesions described so far: malignant lymphomas, mesotheliomas, hamartomas and embryonic tumours.

Immunohistochemical analysis of estrogen receptors in feline mammary gland benign and malignant lesions: comparison with biochemical assay.

Estrogen receptors (ER) were determined by both the biochemical dextran-coated charcoal (DCC-ER) and the immunohistochemical Avidin biotin-peroxidase complex (IHC-ER) methods in proliferative mammary lesions collected from 37 cats: 20 malignant tumors without metastasis at first presentation, seven malignant tumors with lung and/or lymph node metastases and 10 benign tumors and dysplasias. Total number of samples analyzed by both methods was 44. The DCC-ER method was applied to frozen tissue samples and the IHC-ER method was applied to neutral buffered formalin-fixed, paraffin wax-embedded tissue samples by using the NCL-6F11 monoclonal antibody.

Tyrosinase gene expression in clear cell sarcoma indicates a melanocytic origin: insight from the first reported canine case.

The aim of this study was to characterize a metastasizing soft tissue tumor in a dog, which clinically, grossly and histologically showed a close resemblance to human clear cell sarcoma, a soft tissue variant of malignant melanoma. Ultrastructurally, melanosomes were found, indicating a melanocytic origin of the tumor. Using reverse-transcription polymerase chain reaction, expression of the gene encoding tyrosinase was determined in tumor cells.

Genomic organization of the canine p53 gene and its mutational status in canine mammary neoplasia.

To determine whether canine malignancies share common genetic lesions with their human counterparts, and are thus potentially interesting model systems in which to pose questions regarding tumor etiology and progression, we have elucidated the entire exon/intron structure of the canine p53 gene. A search for p53 gene abnormalities in mammary tumor tissue was undertaken utilizing single strand conformation polymorphism analysis. Mutations were detected in exons 4, 5, 6, and 7 of the p53 gene and consisted of nonsense, splicing, and frameshift mutations.

Liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE): a randomized clinical trial in dogs with mammary carcinoma.

In this prospective randomized double-blind clinical study the anti-tumour activity of liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) was evaluated as an adjuvant immunotherapy in dogs with mammary tumours of the simple carcinoma type. Dogs were randomized after surgery to one of two treatment groups, in which they were treated with either L-MTP-PE (2 mg/m2 i.v.

Expression of growth hormone in canine mammary tissue and mammary tumors. Evidence for a potential autocrine/paracrine stimulatory loop.

The role of progestins in the pathogenesis of breast cancer in women remains controversial. To advance this discussion, we report the demonstration and localization of progestin-induced biosynthesis of growth hormone (GH) in canine mammary gland tissue. Nontumorous mammary tissues and tumors, both benign and malignant, were obtained from private household dogs.

P53 gene mutations in osteosarcomas in the dog.

Osteosarcomas in 18 dogs were examined for the presence of p53 mutations in exons 4-8 by single strand conformation polymorphism (SSCP) analysis, followed by sequence analysis in tumors demonstrating abnormal bands in the SSCP analysis. P53 mutations were found in four of the primary tumors in 17 dogs. Metastases studied in two of these dogs in which the primary tumor contained only wild type p53 did not contain mutations, nor those of one dog in which the primary tumor was not studied.

Veterinary cancer epidemiology.

This paper reviews the impact of veterinary cancer epidemiology on veterinary oncology, human oncology, comparative oncology, and on the etiology and pathogenesis of cancer. The detection of clusters of diseased animals has led to the discovery of the infectious, viral-associated nature of malignant lymphoma of cats, poultry, and cattle. Although some viruses (FeLV, BLV) can, under experimental conditions, cross the species barrier, there is thus far no evidence for a zoonotic hazard for the human.

Expression of the gene encoding growth hormone in the human mammary gland.

Progestins cause a syndrome of growth hormone (GH) excess and enhanced mammary tumorigenesis in the dog. This has been regarded as being specific for the dog. Recently we reported that progestin-induced GH excess originates from foci of hyperplastic ductular epithelium of the mammary gland in the dog.

Uterine carcinomas in mother cats after intrafetal inoculation of allogeneic tumor cells (K248 C and P).

Three out of 13 queens that had undergone injection of tumor cells from an allogeneic feline mammary carcinoma cell line through the wall of the pregnant uterus developed a carcinoma of the uterus. The possible role of immune tolerance associated with pregnancy and/or major histocompatibility complex (MHC) compatibility is discussed.

DNA flow cytometry of canine mammary tumours: the relationship of DNA ploidy and S-phase fraction to clinical and histological features.

The DNA ploidy status and S-phase fraction (SPF) of benign proliferative lesions (BPL) and malignant tumours (MT) in the mammary glands of dogs were determined by flow cytometric analysis and the results were related to their clinical and histological features. Seven (14.3 per cent) of 49 BPL and 16 (48.

[Differential diagnosis of non-healing 'fungal'patches in horses].

Dermatophytosis is the most common equine skin disease. Mycotic-like lesions that do not disappear are suspected of being sarcoids. The clinical symptoms and therapeutic interventions for both affections are discussed.

[Oncology, pathology and companion animal practice].

A review of research in veterinary oncology, as executed in Amsterdam and Utrecht, is presented. Also an inquiry into the cooperation between oncologist, pathologist and practitioner is discussed. It is concluded that microscopic tumour diagnosis is practized at too low a scale (+/- 30%).

Expression of epidermal growth factor receptor (EGFR) in non-affected and tumorous mammary tissue of female dogs.

Epidermal growth factor (EGFR), oestrogen (ER), and progestin (PR) receptor concentrations were determined by radioligand binding assay in non-affected mammary tissues (n = 13) and benign (n = 11) and primary/locally recurrent malignant proliferative mammary lesions (n = 45) and metastases (n = 19) in 65 female dogs. The number of specimens expressing EGFR was not significantly different among these tissues, but EGFR concentration was lower in metastases (P = 0.02) than in benign or primary/locally recurrent malignant lesions not mixed with non-affected mammary tissue.

Immunohistochemistry with keratin, vimentin, desmin, and alpha-smooth muscle actin monoclonal antibodies in canine mammary gland: malignant mammary tumours.

Ten malignant canine mammary gland tumours and five metastases from three of these tumours were studied immunohistochemically with monoclonal antibodies (MoAbs) directed against different human keratin types (K), alpha-smooth muscle actin, vimentin, and desmin. In all tumours the neoplastic epithelium was rather homogeneously labelled with the keratin MoAbs RCK 102 (K 5 and 8) and CAM 5.2 (K 8).