Anus Flashcards
What is the most common carcinoma of the anus?
Squamous cell carcinoma (80%)
What cell types are found in carcinomas of the anus?
- Squamous cell carcinoma
- Cloacogenic (transitional cell)
- Adenocarcinoma, melanoma, mucoepidermal
What is the incidence of anal carcinoma?
Rare
What is anal Bowen’s disease?
Squamous cell carcinoma in situ
How is anal Bowen’s disease treated?
Local wide excision
What is Paget’s disease of the anus?
Adenocarcinoma in situ of the anus
How is Paget’s disease of the anus treated?
Local wide excision
What are the risk factors for anal cancer?
HPV, condyloma, HSV, HIV, chronic inflammation, immunosuppression, homosexuality in males, cervical or vaginal cancer, STDs, smoking
What is the most common symptom of anal carcinoma?
Anal bleeding
What are the other signs and symptoms of anal carcinoma?
Pain, mass, mucus per rectum, pruritus
What percentage of patients with anal cancer is asymptomatic?
25%
To what locations do anal canal cancers metastasize?
Lymph nodes, liver, bone, lung
What is the lymphatic drainage below the dentate line?
Below to inguinal lymph nodes (above to pelvic chains)
Are most patients with anal cancer diagnosed early or late?
Late
What is the workup of a patient with suspected anal carcinoma?
H&P; DRE; proctoscopic exam; colonoscopy; biopsy; abdominal and pelvic CT; transanal U/S; CXR; LFTs
What is anal margin cancer?
Anal verge out 5 cm onto the perianal skin
What is anal canal cancer?
Proximal to anal verge up to the border of the internal sphincter
How is an anal canal epidermal carcinoma treated?
NIGRO protocol:
- Chemotherapy (5-FU, mitomycin C)
- Radiation
- Post-radiation therapy scar biopsy (6-8 weeks post-XRT)
What percentage of patients with anal canal epidermal carcinoma have a complete response with the NIGRO protocol?
90%
What is the 5-year survival for anal canal epidermal carcinoma with the NIGRO protocol?
85%
What is the treatment for local recurrence of anal cancer after the NIGRO protocol?
May repeat chemotherapy/XRT or salvage APR
How is a small (< 5 cm) anal margin cancer treated?
Surgical excision with 1-cm margins
How is a large (> 5 cm) anal margin cancer treated?
Chemoradiation
What is the treatment of anal melanoma?
Wide excision or APR (especially if tumor is large) +/- XRT, chemotherapy
What is the 5-year survival rate with anal melanoma?
< 10%
How many patients with anal melanoma have an amelanotic anal tumor?
Approximately 33%, thus making diagnosis difficult without pathology
What is fistula in ano?
Anal fistula, from rectum to perianal skin
What are the causes of fistula in ano?
Usually anal crypt/gland infection (usually perianal abscess)
What are the signs and symptoms of fistula in ano?
Perianal drainage, perirectal abscess, recurrent perirectal abscess, “diaper rash”, itching
What disease should be considered with fistula in ano?
Crohn’s disease
How is the diagnosis of fistula in ano made?
Exam, proctoscope