DL: FISS

Question 1

What cellular origin does FISS have?

Answer 1

Mesenchymal

Question 2

What are the predispositions to FISS?

Answer 2

None
No sex, breed, age predisposition
No vaccine/injection predisposition
Originally thought to be due to the adjuvant(s)
Now thought possibly to be any number of causes including just the stabbing action of the needle itself!

Question 3

Where does Feline post-trauma intraocular sarcoma occur?

Answer 3

• Periocular and intraocular area

* common in cats who had experienced some form of trauma

Question 4

Can FISS be cystic?

Answer 4

Yes

Question 5

How do you diagnose FISS?

Answer 5

• PE and history – location, injection site
• Cytology
• Histopathology

Question 6

Why do an incisional rather than an excisional biopsy for tumours?

Answer 6

Incisonal (you take a section of it, do histopathology and then remove if necessary as the tumour won’t have been enhanced by this procedure) OR excisional (don’t choose this for tumours, risk that if you don’t remove all of the tumour, then you will have an area around the scar left from the biopsy to avoid PLUS another 3-5cm perimeter which makes the surgery bigger).

Question 7

What do the Feline Task Force Guidelines suggest you do for a mass in a vaccination area?

Answer 7

o Biopsy if lump persists > 3 months
o Biopsy if >2cm (unlikely that a vaccine granuloma will be bigger than 2cm)
o Biopsy if it increases in size within one month post-vaccine
o ALWAYS INCISIONAL!

Question 8

What is the major DDx for a FISS?

Answer 8

VACCINE GRANULOMA (i.e. an adverse reaction to the granuloma)

Question 9

Define DFI

Answer 9

Disease Free Interval

Question 10

Define Sx

Answer 10

Surgery

Question 11

Why is the outcome if the first surgery is performed by a referral surgeon?

Answer 11

A second surgery is less likely to be successful since the surgical site will be larger, the original anatomy will be altered, seeding through tissue planes (harder to assess on imaging and at surgery), likely that previously clean tissue will be contaminated, at time of first treatment there has been less time to metastasize, tumour upstaging.

Question 12

What is the recommended treatment for FISS?

Answer 12

• Aggressive, multi-modality treatment recommended. Radical surgery necessary at start. Amputation if possible. Wide and deep surgical margins (3-5cm). Use radiation to shrink/debulk if not possible.
• Incompletely excised/narrow margins: adjuvant radiation therapy and chemotherapy should be performed. Surgery + radiation DFI 19m, 40% cure, Doxorubicin/carboplatin

Question 13

Define FVRCP

Answer 13

The core feline vaccines

Feline Viral Rhinotracheitis, Calicivirus, Panleukopaenia, Chlamydiosis (Chlamydophila pssitaci)

Question 14

What are the published recommendations to reduce the risk of FISS?

Answer 14

• Avoid administering multiple vaccines in the same site
• Don’t over-vaccinate
• Administer vaccines SQ as far distally as possible
• Use non-adjuvant vaccines
• Educate owners – to check the site, bring cat back in if there are any lumps
• Administer SQ vaccines at extremities or at the base of the tail