Canine mast cell tumours: a review of the pathogenesis, clinical features, pathology and treatment

Abstract

The biological behavior of MCTs is highly variable and improvements in understanding of the natural history and prognostic indicators as well as the indications for multimodal therapy, will further result in better outcomes in canine patients with MCT. PATHOGENESIS OF MCTsThe aetiology of MCTs is unknown but, as with most neoplasms is probably multi-factorial, and the well- Mutations of c-kit, characterized by internal tandem duplications, produce a constitutively activated KIT protein in the absence of ligands 35,49,58 that leads to extracellular signal-regulated kinase phosphorylation. 58 Little is known about the consequences of these mutations. However, c-kit mutations and aberrant KIT protein localization are associated with increased expression of Ki67 and argyrophilic nucleolar organizing regions (AgNORs), both of which are markers of increased cellular proliferation. 47 Moreover, in vitro testing of drugs targeting the KIT tyrosine kinase receptor demonstrated inhibition of proliferation of canine MCT cell lines and primary neoplastic MCs, associated with cell-cycle arrest and apoptosis. 59 Despite these findings, no genetic defects in c-kit are identified in more than 60% of canineMCTs. This suggests that, mutations in this gene are associated with the development or progression of some MCTs, but mutations in other genes are likely to be involved in the initiation and progression of most canine MCTs.

Epidemiología de mastocitoma en caninos en una región de Mato Grosso do Sul Brasil

“…Diversos autores afirmam que raças braquiocefálicas, como Boxer, Boston terrier, Bullmastiff e Bulldog inglês e a faixa etária por volta dos oito anos são os fatores que mais predispõem a essa neoplasia (Furlani et al, 2008, Nelson and Couto, 2015, Palma et al, 2009. Welle et al (2008) confirmaram a maior incidência de mastocitoma nestas raças e referiram se a predisposição em raças de grande porte a terem maior probabilidade de desenvolverem mastocitoma.…”

“…Estas raças são citadas pela literatura como predispostas a este tumor, além de Buldogue e animais mestiços (Costa-Casagrande et al, 2008, Welle et al, 2008, Strefezzi et al, 2010, Costa-Poggiani et al, 2012. Outras raças como poodle 3,8% (1) e Shnauzer 3,8% (1) não são indicadas na literatura como predispostas ao mastocitoma.…”

Systemic mastocytosis with terminal leukemic manifestation in two dogs

“…Unlike cats, dogs rarely develop visceral mastocytosis (4,7,9) and, when it occurs, it is commonly associated with a primary cutaneous MCT (3,18). In a previous study of canine SM, 14 of 16 dogs had a primary cutaneous MCT and only two had SM without a skin tumor (12), as found in Case 2.…”

“…In veterinary literature, localized extracutaneous MCT has been occasionally reported (3,5,15,16,18). Unlike cats, dogs rarely develop visceral mastocytosis (4,7,9) and, when it occurs, it is commonly associated with a primary cutaneous MCT (3,18).…”

Relação da expressão de fatores de crescimento celular (IGF-1) e (SCF) com fatores prognósticos e o alvo da rapamicina em mamíferos (m-TOR) em mastocitomas cutâneos caninos

“…Estudos indicam que, cerca de 15-40% dos MTCs contém mutações no gene KIT que codifica o receptor tirosina quinase c-KIT (Letard, et al 2008, Welle et al 2008. Seu ligante é o fator de célula tronco (SCF), conhecido também como fator de crescimento para mastócitos que é um fator de crescimento expresso em diversos tipos de tecidos (Linnekin, Jelacic, Shivakrupa 2003, Roskoski 2005.…”