DM2 Pt5-3 Feline Injection Site Sarcoma (FISS) Flashcards
(37 cards)
What were feline injection site sarcomas (FISS) originally called?
They were originally called “vaccine site-associated sarcomas.”
When were feline injection site sarcomas first reported, and which vaccine was initially linked?
They were first reported in 1991 and linked to rabies vaccination.
Why were FISS renamed from vaccine site-associated sarcomas?
Because they can occur after any injection, not just vaccines, including antibiotics and corticosteroids.
What is one significant risk factor for developing FISS?
The number of injections at a site; 3-4 vaccinations in the interscapular region doubles the risk.
How does the temperature of a vaccine affect the risk of FISS?
Administration of cold vaccines increases the risk compared to room temperature vaccines.
Does the brand or manufacturer of the vaccine increase the risk of FISS?
No, vaccine brand or manufacturer is not associated with increased risk.
Does re-using disposable syringes increase the risk of FISS?
No, re-using disposable syringes is not associated with increased risk.
Does shaking multidose vials or massaging the area post-vaccination increase the risk?
No, neither shaking vials nor massaging the area increases the risk of FISS.
What is the primary treatment challenge for interscapular FISS?
Interscapular FISS are challenging to treat due to their aggressive nature.
What diagnostic tests are recommended for assessing FISS?
Full haematology, biochemistry, FeLV/FIV status, urinalysis, and biopsy are recommended. Cytology is not reliable.
How long should inflammatory reactions post-injection resolve?
Inflammatory reactions should resolve in 6–8 weeks.
What is required to definitively diagnose FISS?
A biopsy is required to definitively diagnose FISS.
What imaging techniques are recommended for staging FISS?
Thoracic CT or three-view inflated thoracic radiography to check for metastases.
Where does FISS most commonly metastasize?
The most common site for metastasis is the lungs, but it can also spread to liver, lymph nodes, and subcutaneous tissue.
What are the recommended surgical margins for FISS excision?
3–5 cm lateral margins with two muscle layers or bone as the deep margin.
Why is the first surgery critical in treating FISS?
The first surgery is the most effective for curative treatment.
What complications may occur after radical surgery for FISS?
Complications include wound dehiscence and seroma.
What are the key components of postoperative care after radical FISS surgery?
Support dressing, multimodal analgesia (opiates, NSAIDs, local anesthesia), suction drains, and assisted feeding.
What are the factors that influence prognosis in FISS treatment?
Factors include location of FISS, clean vs dirty margins, number of surgeries, surgeon experience, tumor grade, and metastasis development.
Why is recurrence common even in cases with clean surgical margins?
Due to the infiltrative nature of the tumor and potential ongoing inflammation leading to further tumorigenesis.
What is the tumor recurrence rate in FISS cases with histopathological clean margins?
Recurrence rates in cases with clean margins range from 14–50%.
When is radiotherapy used in FISS treatment?
Radiotherapy is used as an adjuvant therapy postoperatively or preoperatively to treat microscopic disease.
Why might tumor cells become more resistant to radiotherapy after surgery?
Surgery can damage blood supply to tumor cells, making them more radioresistant.
Is chemotherapy proven to be effective in treating FISS?
The efficacy of chemotherapy is unproven, though it is used due to the high metastatic rate of FISS.
