Description
Feline injection sarcomas are highly aggressive mesenchymal tumours which occur at the site of a previous injection, leading to an inflammatory reaction and uncontrolled fibroblast proliferation. It is important to note that although vaccines are often implicated in the development of such tumours, feline injection site sarcomas can be associated with all subcutaneous injections including microchipping.  Although infrequent (estimated at 1-10 per 10,000 vaccinations), management of these tumours is challenging due to their size and locally invasive nature.  Distant metastasis occurs in only approximately 20% of cases, however local recurrence is reported in up to 40% of cats with apparently clean histopathological margins.
Management of these tumours requires detailed and appropriate pre-operative advanced imaging for staging and to aid with surgical planning.  Wide surgical margins and a well planned surgery by an experienced surgeon have been associated with the lowest recurrence rates and reconstruction of such excisions can be challenging. Chemotherapy and radiotherapy are also an essential part of the management of feline injection site sarcomas. This talk will aim to address both the epidemiology and suspected aetiopathogenesis of feline injection site sarcomas and also discuss the surgical management, post-operative care and neoadjunctive/adjunctive therapies used in the treatment of such tumours.
Rachel Hattersley BVetMed(Hons) CertSAS DipECVS MRCVS, European specialist in small animal surgery at  Davies Veterinary Specialists.