George Wins the Day

January 12, 2021

Feline Injection-site sarcomas (FISS) are aggressive cancers and have been a problem for veterinary oncologists for decades. The thought is that they are triggered by an inflammatory reaction, such as injections (hence why they often occur between the shoulder blades or on top of the neck).

However, overall they are very rare (compared to the many cats that receive various injections) and so cats need to be predisposed to these tumours in other ways (e.g. their genetics). We still don’t know how to predict which cats are at risk. These tumours tend to grow quickly and with only small/minimal surgeries (e.g. to just shell out the lump or only remove a small amount of surrounding tissue) they tend to recur quickly and become harder to treat. This is because the lump that can be felt on the cat is only the tip of the iceberg – at a microscopic level, there are lots of cancer cells surrounding the main mass, sometimes even centimetres away. The best results have been shown by radical surgeries, such as that described below for George.

Cats tend to live for years after such surgeries and only recur near the surgical site in around 15% of cases (compared to up to 80%+ of cases managed with less aggressive surgeries). George’s owner noted a lump on the back of his neck when he was stroking him one evening. He immediately took George to his primary care vet, who promptly examined him and confirmed the presence of a mass. They were concerned that the mass could be a feline injection-site sarcoma (FISS). Therefore, rather than attempt removal of the lump, a biopsy was taken. Unfortunately, this confirmed the presence of a FISS. George’s vet referred him to Southfields to see James Elliott, one of the medical and radiation oncologists.

James examined George and fortunately the lump was still relatively small. There had been very little tissue disruption caused by the biopsy and a CT scan revealed no major extension of the lump away from the main site on the neck. Luckily there was no evidence of tumour spread to other sites in the body.

James recommended a radical surgical excision of the mass. This involves taking 5cm of tissue all the way around the mass and at least 2 deep planes of healthy-appearing tissue beneath the mass. This surgery sometimes involves removing muscle or bone, to ensure removal of all the cancer. Surgery was performed by Henry L’Eplattenier, one of Southfield’s Specialist soft tissue surgeons and Clinical Director. The procedure went well, with the help of our nursing team and anaesthetists who help greatly with pre-emptive pain control to ensure these patients are comfortable.

George went home after a couple of days and was pretty much instantly back to normal. His wound healed well without problem. Great news followed a week later, when the biopsy results revealed that the mass had been excised with very wide margins of normal tissue around it. Hopefully, this means all the cancer has been removed and limits the chance of the tumour recurring to low levels.

In part, George’s case was able to be successfully managed because his primary care vet had realised what his lump might be, and not tried to remove it. Attempting removal of FISS without knowing what they are tends to lead to incomplete removal, greater difficulty in performing a curative excision later due to disruption of normal tissues and ultimately, tumour recurrence. George’s swift and appropriate management by his vet enabled rapid referral for his assessment and specialist surgery which ultimately lead to a great outcome.

Southfields are fortunate to have an amazing multi-disciplinary team of oncologistssurgeons and anaesthetists who can streamline the management of these cases. Sometimes these cases are too advanced for a radical surgery and require a combination of surgery and radiation for effective management. This can also be performed at Southfields if required.

See Southfields Oncology Service for further information.