An immunohistochemical study of canine spontaneous gastric polyps.

Irina Amorim,Cornel Cătoi,Celso A Reis,Augusto M Faustino,Andreia Ferreira,Fátima Gärtner,Marian A Taulescu,Alexandra Rêma

doi:10.1186/s13000-014-0166-z

Abstract

BackgroundGastric polyps (GP) are characterised by luminal overgrowths projecting above the plane of the mucosal surface that can be classified as non-neoplastic and neoplastic lesions. In humans, recent studies have drawn attention to the malignant potential of some of these lesions. However, gastric polyps are uncommon lesions in dogs.FindingsIn this study, the presence of Helicobacter spp., the cellular proliferative activity, potential phenotypic alterations, COX-2 and p53 expression in canine spontaneous gastric polyps were investigated. The expression of these molecules was also studied in normal canine gastric mucosa in order to gain further knowledge of the significance of their loss or overexpression in gastric lesions.ConclusionsThe normal expression of almost all the factors evaluated, along with the reduced proliferative activity is strongly suggestive that, in dogs, spontaneous gastric polyps are not only a rare finding but also of benign nature.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_166

Highlights

Gastric polyps (GPs) are considered a heterogeneous entity broadly defined as luminal lesions projecting above the plane of the mucosal surface that can be biologically classified as non-neoplastic and neoplastic lesions
Discussion & conclusion Studies regarding COX-2 in human normal gastric mucosa (NGM) reported lack [15,16], weak [17] or generalised expression [18]. These discrepancies are perhaps related to the primary antibody and to the scoring system adopted for immunoreactivity evaluation
The consistent expression of COX-2 in NGM could be explained by two hypotheses: (1) COX-2 is constitutively expressed in canine gastric mucosa; or (2) recent studies showed that H. pylori induced COX-2 expression in human gastric mucosa and McCarthy et al [19] concluded that COX-2 expression in antral mucosa was reduced but not eliminated in the epithelium after successful eradication of H. pylori

Summary

Introduction

Gastric polyps (GPs) are considered a heterogeneous entity broadly defined as luminal lesions projecting above the plane of the mucosal surface that can be biologically classified as non-neoplastic and neoplastic lesions. Regarding non-neoplastic polypoid growths, the World Health Organization (WHO) for the classification of tumors in domestic animals presents a simplest scheme where only two entities are recognized: the hyperplastic (regenerative) and the inflammatory (benign lymphoid) polyps. The former are histologically identical to the human homonymous lesion and the gold standard of the later is the presence of a normal epithelium covering a granulation tissue core infiltrated by a variety of inflammatory cells, sometimes accompanied by lymphoid aggregates with prominent germinal centers [4]. Findings: In this study, the presence of Helicobacter spp., the cellular proliferative activity, potential phenotypic alterations, COX-2 and p53 expression in canine spontaneous gastric polyps were investigated. Virtual Slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/ 13000_2014_166

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