Chapter 12, part 4 Flashcards
Familial adenomatous polyposis
Development of numerous colonic polyps >100
Autosomal dominant mutation of APC tumor suppressor gene located on chromosome 5q
Gardner syndrome
Polyposis and osteomas, sarcomas, and epidermoid inclusion cysts
Turcot syndrome
Polyposis and brain tumors
When to screen for familial adenomatous polyposis
Starting for high risk ppl at 10 yo
If + for mutation: total proctocolectomy and permanent end ileostomy, total proctocolectomy with IPAA or total abdominal colectomy and ileorectal anastamosis
What is the MCC of hereditary colon cancer?
Hereditary nonpolyposis colorectal cancer or Lynch syndrome
Defects in DNA mismatch repair genes
When does hereditary nonpolyposis colorectal cancer (Lynch syndrome) usually become colon CA?
Around 44 yo
What is recommended for women with hereditary nonpolyposis colorectal cancer (Lynch syndrome)?
Prophylactic total ab hysterectomy and bilateral salpingo-oophorectomy
Amsterdam criteria
Three affected relatives, with 2 consecutive generations, and with at least 1 family member diagnosed before age 50
If identified via criteria, need colonoscopy q2yrs starting between 20-35, and then yearly after 35
Multiple polyposis coli or juvenile polyposis coli
Autosomal dominant syndrome associated with SMAD4 gene
Hamartomas and bleeding
Dx and tx of multiple polyposis coli or juvenile polyposis coli
Upper and lower endoscopy starting at 15-25
Endoscopic polypectomy
Peutz-Jeghers syndrome
Autosomal dominant dz associated with mutations in STK11
Presentation of Peutz-Jeghers syndrome
Multiple GI hamartomatous polyps and hyperpigmentation of lips, buccal mucosa, and digits
Dx of Peutz-Jeghers syndrome
Endoscopy with polypectomy as indicated q2yrs
Screening for cancer
Colonoscopy starting at 50 and q5-10 yrs: for no risk
Moderate risk (CA in 1st degree relative >60): start at 40 and do q5-10yrs
High risk (sigmoidoscopy): FAP-10 yo and yearly until 40
High risk-Lynch syndrome- 20 yo and q2yrs until 35, then yearly
High risk- IBD- 10 yr after start of colitis, then q1-2y
Dx and staging of CA
Start with colonoscopy and then do radiographic exam to check for mets
MC site of mets= liver (need to do CT of abdomen)
CEA (food for surveillance after curative therapy)
PET
Cancers in mid and upper rectum- rigid proctoscopy
How to treat a resectable tumor without mets in colon cancer
Segmental colectomy
Margins greater than or equal to 5 cm
Need minimum of 12 lymph nodes in specimen
How to treat tumors adherent to adjacent organs in colon cancer
Resected en bloc
What is offered to any pt with evidence of spread in colon cancer?
Chemo
5-FU or leucovorin with either oxaliplatin or irinotecan
How to treat locally advanced rectal cancer
Neoadjuvant chemo
How to treat total mesorectal excision in rectal cancer
Complete removal of rectal tumor and regional lymph nodes
2 cm distal margin
How to treat tumor in mid/upper rectum
Low anterior resection (LAR) with colorectal anastamosis
How to treat preexisting fecal incontinence or with very low rectal cancer
Abdominoperineal resection (APR)
How to treat metastatic dz
Asymptomatic primary colon tumor and unresectable metastatic disease: chemo
What is considered lower GI bleeding?
Bleeding distal to ligament of Treitz
What is the MCC of lower GI bleeding?
2nd MCC?
1/2 occur from diverticular dz
Arteriovenous malformations
Dx of lower GI bleed
Find the bleed
NG tube lavage to r/o upper GI bleed
Proctoscopy to r/o anorectal cause
Need large-bore IV access and fluid resuscitation
Labs/rads for lower GI bleed
CBC and coag studies
Type and cross
Colonoscopy would not be good if a ton of blood
Could do radionuclide scan and inject tagged RBCs (but need to be actively bleeding)
Selective visceral angiography- better info and can offer therapeutic options
Tx of lower GI bleed
Surgery may be needed if ongoing transfusion requirement (6 L over 24 hrs)
What cancers are MC found in the appendix?
Carcinoid tumors
When is carcinoid syndrome caused?
When carcinoid tumors get to the base of the appendix
Presentation of carcinoid syndrome
Cutaneous flushing
Bronchospasm
Secretory diarrhea
Cardiac valvular lesions
Mucocele
Accumulation of mucin within the lumen d/t proximal obstruction
Mucinous crystadenomas
Benign lesions associated with dilated mucin filled appendix and adenomatous epithelium
Mucinous crystadenocarcinoma
Malignant
Can cause pseudomyxoma peritonei- peritoneal cancer becomes seeded by cancer cells that continue to secrete mucin- treat with surgical debulking
Abscess or fistula-in-ano
Obstruction of anal glands can lead to infection and if they track down toward anal orifice, perianal abscess
MC type of anorectal abscess
Intersphincteric abscess
Infection can remain in intersphincteric plane
Ischiorectal abscess
Can penetrate laterally through the external sphincter
Supralevator abscess
Can track superiorly above levator ani
Horseshoes
Infection starts in postnatal space and spread bilaterally
What are 50% of anal abascesses?
Fistula in ano
How can the general course of tract of fistulas in ano be predicted?
On the basis of site of external opening using Goodsall’s rule
Presentation of abscess or fistula in ano
Anal pain
Swelling
Fever
Tender mass
Dx of abscess or fistula in ano
CT or MRI
Tx of abscess or fistula in ano
Incised and drained
External opening should be made on the anal side of the abscess
Intershpincteric- drain into anal canal via sphincterotomy
Postnatal- incising between the coccyx and anus
Horseshoe- Hanley technique
Tx of fistula in ano
If identified with abscess: seton should be placed
Then staged procedure 8 wks later
Intersphincteric and superficial transphincteric fistulas: open and close by secondary intent= fistulotomy
Types of hemorrhoids
Right anterior
Right posterior
Left lateral
Internal hemorrhoids
Above dentate line- BRB and prolapse
1st degree internal hemorrhoids
Bulging within lumen without prolapse
2nd degree internal hemorrhoids
Prolapse with straining but reduces
3rd degree internal hemorrhoids
Prolapse that reduces only with digital manipulation
4th degree internal hemorrhoids
Irreducible prolapse
External hemorrhoids
Below dentate line
Acute discomfort
Dx of hemorrhoids
Anoscopy
Tx of hemorrhoids
1st and 2nd: nonsurgical therapy: rubber band ligation
Symptomatic 2nd, 3rd, and 4th: surgical tx
Hemorrhoidectomy: prone jackknife position
Pilonidal dz
Episodic infection of subcutaneous tissues of the superior gluteal cleft
Subcutaneous abscess that drains spontaneously or requires surgical drainage
What leads to recurring infections in pilonidal dz
Complex tunneling sinuses
Tx of pilonidal dz
Need surgical resection
MIdline excision
with/without primary closure of the defect
Marsupialization: skin at wound edge can be sutured to the base to eliminate overhang and make the wound smaller
Anal fissue
Linear tears in the andoderm distal to the dentate line
Where do most anal fissures occur?
Posterior midline
Presentation of anal fissure
Constipation or intense pain with defecation is a common complaint
Chronic fissure is classically associated with heaped up epidermis (sentinel tag), which is a marker of chronic inflammation
Tx of anal fissue
Conservative- fiber supplements and sitz bath
Refractory cases: lateral internal sphincterotomy
When is rectal prolapse most common?
Women > 50 yo
Presentation of rectal prolapse
Extrusion of rectal mucosa from the anus when a pt bears down
Tx of rectal prolapse
Rectoplexy with or without resection of the redudant sigmoid colon
Altemeir procedure- most common perineal approach
