Perianal Tumors Flashcards
(23 cards)
What are the clinical signs associated with AGASACA?
Incidental finding 47%
Mass effect in perineal region
Bleeding/discharge
Excessively licking perineal region
Tenesmus/abnormal feces
Fecal/urinary obstruction
PU/PD (paraneoplastic hypercalcemia)
What is the biological behavior of AGASACA?
Aggressive
25 - 95% LN metastasis at presentation
0 - 40% distant metastasis at presentation
Size of tumor does not correlate with presence of metastatic disease
How is AGASACA staged?
FNA anal sac
CBC (hypercalcemia)
Urinalysis
Thoracic CT
Abdominal CT/MRI (LNs)
What is the pre-op management of AGASACA?
Treat hypercalcemia if significant - IV fluids, diuretics, bisphosphonate, calcitonin
Blood type if LN extirpation
What is the most common treatment for AGASACA?
Anal sacculectomy + LN extirpation (do both sx in dorsal)
Always do LN extirpation first!!
What is the approach for LN extirpation?
Caudal abdominal approach (umbilicus to pubis)
Identify the relevant LNs
When is LN extirpation surgery not indicated?
Invasion to musculature
360 degree involvement of vessels
If extensive seeding into abdominal wall after previous sx
How is an anal sacculectomy performed?
Sternal recumbency
Post-Op Care: Anal Sacculectomy
Usually go home same day
Liposome encapsulated bupivacaine
NSAIDs
Post-Op Care: Laparatomy and Anal Sacculectomy
Monitor for bleeding overnight
Liposomal encapsulated bupivacaine
Opioids overnight
NSAIDs
AGASACA Re-Staging
q3-4m for 18m, then q6m
What complications are associated with anal sacculectomy?
Infection (10%)
Local recurrence (20%)
Fecal incontinence (rare)
Rectal perforation
Rectocutaneous fistula (rare)
Hypocalcemia (rare)
What are alternative options to surgery for AGASACA?
Radiation - IMRT, SBRT
Consider sx for primary tumor and radiation for LNs when not surgical
What is the prognosis for AGASACA patients?
Small, no mets: MST 1237d w/o chemo
LN mets: MST 293 - 448d
Stage 3b: MST 182d, MST 447d w/ radiation
Distant mets: MST 71 - 82d
Biologic behavior: perianal gland adenomas
Associated with plasma androgen levels
May ulcerate but usually not invasive or fixed!!
What type of tumor makes up the majority of perianal tumors?
Perianal gland adenomas
Biologic behavior: perianal adenocarcinoma
NOT androgen dependent
Locally invasive and can metastasize (LNs, lungs, kidney, liver, bone)
How are perianal adenocarcinomas diagnosed?
Incisional biopsy
FNA does not differentiate consistently between adenoma and carcinoma
What breeds are associated with perianal adenocarcinoma?
GSD
Arctic Breeds
Compare the characteristics of a perianal adenoma and adenocarcinoma
Adenocarcinoma
Adenoma
