P OST - MORTEM F INDINGS IN C ETACEANS S TRANDED
E- CADHERIN EXPRESSION IN CANINE MALIGNANT MAMMARY TUMOURS
RELATIONSHIP TO OTHER CLINICO
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PATHOLOGICAL VARIABLES23rdMeeting of the European Society of Veterinary Pathology 7575 Matos AJF1, Lopes C1, Carvalheira J1, Santos M1, Rutteman GR2, Gärtner F1,3
1Institute of Biomedical Sicences of Abel Salazar (ICBAS), University of Porto, Porto, Portugal
2Utrecht University Clinics of Companion Animals, Utrecht, The Netherlands
3Institute of Pathology and Molecular Immunology of the University of Porto (IPATIMUP), Portugal Proceedings of the 23 Meeting of the European Society of Veterinary Pathology
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Mast cell tumour (MCT) is one of the most common skin tumours of the dog. It has been estimated that they represent 6% of all tumours and account for approximately 13% of all cutaneous tumours in the dog. Several breeds of dogs are predisposed to develop this kind of skin tumours, including Boxers, Boston terriers, bull terriers, weimaraners, and Labrador retrievers. Tumours are usually multiple and may involve any regions of the body skin. Most tumours occur in middle-aged dogs and there is no sex predilection. We report a case of multiple cutaneous MCT in a 9-years old Boxer male, during a 4-years period. The dog was previously submitted to surgery for excision of an MCT for three consecutive years, at the age of 6, 7 and 8 years old, respectively. At the age of 9 years the dog was presented with 17 cutaneous lesions, all diagnosed as MCT. The aim of our study is to describe the morphologic features of the MCTs and to evaluate their immunoreactivity profiles of a proliferation marker. Thin sections were obtained from formalin-fixed, paraffin-embedded tissues and routinely stained with haematoxilyn and eosin. Tumours were graded according to Patnaik's histopathologic grades, and were also evaluated for the presence of necrosis. The cell proliferation index of these tumours was assessed with a standard avidin-biotin complex (ABC) immunohistochemistry protocol, using a monoclonal antibody directed against Ki-67 (MIB-1) as the primary antibody.
The results have shown that all the grade I MCTs (10/10) had an average percentage of cells positive for Ki-67 below 7% and, with exception of one tumour, necrosis was absent. Grade II and III tumours had an average percentage of cells positive for Ki-67 higher than 26% and in 7 out of ten tumours, necrosis was present. The number and grade of these tumours seems to increase with age. The proliferation index of these tumours seems to be correlated with the tumour's grade, however, no significant correlation was determined between the presence of necrosis and tumour grade or the proliferation index.
M
AST CELL TUMORA
CASE REPORTGil da Costa RM1, Lopes C1 and Gärtner F2
1Instituo de Ciências Biomédicas de Abel Salazar - ICBAS, University of Porto, Porto, Portugal.
2Institute of Molecular Pathology and Imunology of the University of Porto (IPATIMUP), Porto, Portugal Proceedings of the 23 Meeting of the European Society of Veterinary Pathology
PNL2 is a recently generated monoclonal antibody that recognizes melanocytic cells and melanomas. Although the antigen recognized by PNL2 is not known yet, recent studies on human melanomas have confirmed its usefulness as a diagnostic marker.
In this study, we compared the immunoreactivity of PNL2 and MART1 (A103) on benign and malignant melanomas and on different non-melanocytic tumors.
Validation of PNL2 on canine melanomas was performed by Western blotting. PNL2 and MART1 immunoreactivity was tested on frozen samples of canine melanomas and on formalin fixed, paraffin embedded specimens of a wide panel of melanocytic and non- melanocytic tumors and normal canine tissues.
No staining was observed in cells other than melanocytes in normal tissues. All non- melanocytic tumors tested (carcinomas, sarcomas, fibrosarcomas, leiomiosarcoma and PNST) stained negative.
Melanocytic tumors stained positive with both PNL2 and MART1, regardless their benign vs malignant nature and their primitive vs metastatic origin. Staining was generally most intense and diffuse in epithelioid cell phenotype. In skin melanomas, PNL2 staining was more prominent in cells at the dermo-epidermal junction.
In contrast to human studies, no PNL2 immunoreactivity of granulocytes was observed.
In conclusion, PNL2 is a valuable tool for diagnosis of formalin-fixed melanocyte tumors.
PNL2,
A NOVEL MONOCLONAL ANTIBODY FOR MELANOCYTIC TUMORS:
IMMUNOHISTOCHEMICAL STUDY OF ITS REACTIVITY ON CANINE MELANOMAS AND COMPARISON WITH
MART1.
23rdMeeting of the European Society of Veterinary Pathology 7777 Giudice C.*, Rondena M.*, Ceciliani F.§, Stefanello D.#, Finazzi M.*
Facoltà di Medicina Veterinaria, Sezione di Anatomia Patologica Veterinaria e Patologia Aviare, via Celoria, 10 - 20133 Milano (Italy).
Proceedings of the 23 Meeting of the European Society of Veterinary Pathology
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Caprine arthritis-encephalitis (CAE) is a persistent lentiviral disease. CAE eradication programs are mainly based on serological screening of goats. Aim of our study was to immunohistochemically investigate the presence of viral particles in tissues from seronegative goats. Samples of lung, udder and bone marrow were obtained from 29 regularly sloughed goats, formalin fixed and processed for histology. Microtomic sections were HE stained and immunohistochemically stained with mAb 1A7 anti- capsidic protein CA-p27. Histologically, interstitial pneumonia was present in 22/29 lungs and moderate BALT hyperplasia in 11/29. Interstitial, lymphoplasmacytic mastitis was detected in 21/29 cases, and moderate mammary fibrosis in 12/29. Bone marrow samples were composed of normal adipose and fibro-vascular tissues. Ca-p27 was immunohistochemically detected in 12/29 goats within bronchial (8/12) and mammary epithelium (7/12). More rarely, stromal fibrocytes, macrophages and endothelial cells in both organs stained positive. Bone marrow stromal cells were positive in 7/12 cases.
CA-p27 immunodetection in BMSCs, bronchial and mammary epithelium is consistent with previous results on seropositive goats. Our observations on seronegative animals suggest that CAE virus can subsist in reservoir cells of goats without detectable serum antibody. Further investigations (viral isolation) will elucidate if these results indicate the presence of CAE provirus or defective virus.
I
MMUNOHISTOCHEMICAL OF CAPSIDIC PROTEIN P27 (CA-
P27)
IN TARGET TISSUES OF CAEV SERONEGATIVE GOATS
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Giudice Chiara1, Gelmetti Daniela2, Gaffuri Alessandra2, Sacchi Cristina2, Gibelli Lucia2.
Facoltà di Medicina Veterinaria, Sezione di Anatomia Patologica Veterinaria e Patologia Aviare, via Celoria, 10 - 20133 Milano (Italy).
Proceedings of the 23 Meeting of the European Society of Veterinary Pathology
Canine aural cholesteatoma (AC) is a rare, destructive lesion of the middle ear that parallels human acquired cholesteatoma. We report histological and immunohistochemical features of cholesteatomas in three dogs of different breeds. A diagnosis of AC was emitted on CT examination and Total-Ear-Canal-Ablation/Lateral- Bulla-Osteotomy was performed in all cases. Specimens from surgery were processed for histology. Micrometric sections were immunostained with monoclonal antibodies against cytokeratin (CK) 14, 16 and 19 and Ki67 (MIB1) and compared with samples of non- cholesteatomatous chronic otitis (NC-CO) and normal external auditory canal (EAC).
Histologically, cholesteatomatous cysts were lined by 20/25 layer thick, keratinized squamous epithelium, resting on dense fibrovascular stroma, infiltrated by lymphocytes and plasmacells.
Immunohistochemically, normal EAC epithelium stained CK14 positive; CK16, CK19 and Ki67 negative. NC-CO epithelium stained CK14 and, focally, CK16 positive.
Cholesteatoma epithelium was intensely CK14 and CK16 positive and CK19 negative.
MIB1 immunolabelling was not significantly different in CO and AC.
According to previous observations on dogs and humans, cholesteatoma is a form of epidermal cyst. In our cases, cholesteatoma epithelium overexpressed CK16, consistently with the proliferative nature of the lesion. Low Ki67 expression suggested a low growth rate, consistently with the hypothesis that acquired cholesteatoma is a slowly progressive disease.
C
ANINE AURAL CHOLESTEATOMA:
HISTOLOGICAL AND IMMUNOHISTOCHEMICAL CHARACTERISTICS OF THREE CASES.
23rdMeeting of the European Society of Veterinary Pathology 7979 Giudice C.*, Rondena M.*, Signorelli P.°, Ceppi S.^, Travetti O.§, Digiancamillo M. §, Finazzi M.*, Mortellaro C.M.°
Facoltà di Medicina Veterinaria, Sezione di Anatomia Patologica Veterinaria e Patologia Aviare, via Celoria, 10 - 20133 Milano (Italy)
Proceedings of the 23 Meeting of the European Society of Veterinary Pathology
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Three-days-old, male foal was presented for the autopsy. The animal died with a signs of septic condition during the course of the antibiotic therapy. Autopsy revealed severe signs of septicemia with miliary necrotic nephritis, hemorrhagic focal colitis and serofibrinous peritonitis. Disseminated peritoneal, subepicardial and subendocardial hemorrhages were seen. Liver and spleen (reticular hyperplasia) were enlarged, and the lungs were congested.
Microscopically, severe bacterial, necrotic, multifocal lesions were seen in the kidneys, lungs and liver. Bacterial colonization was found also in the brain along with mononuclear perivascular encephalitis. Bacteriological examination revealed bacteria E.
coli.
This case shows that some time may be difficulties in differentiation between the Actinobacillus equi septicemia and E. coli septicemia. Autopsy findings may be almost the same in both cases, but the histopathological examination of the kidneys showing extraglomerular bacterial colonization may be helpful in establishing correct diagnosis.