GI Section 1: Luminal (Colon/Rectal CA/Colon Misc Masses)) Flashcards
Applecore appearance in colon CA
Cancers on the right tend to a. ___.
Cancers on the left tend to b. ___.
Cancers on the right tend to bleed (present with bloody stools, anemia).
Cancers on the left tend to OBSTRUCT
Large bowel intussusception in adult =
Mallignancy
Colon CA likes to Met to the?
Liver
Liver METS on MRI
Liver Mets will classically be T 1 Dark, T2 Mildly Bright (“evil grey”), heterogenous non-progressive in enhancement, sometimes target.
Occasionally arises in the anus (think HPV).
Squamous Cell Carcinoma
Most rectal CA are what type?
AdenoCA (98%)
Low rectal cancer definition
0-5 cm from the anorectal angle
What type of rectal CA has the highest recurrence rate?
Low rectal CA
How do you stage rectal CA?
MRI - you only need T2WI (contrast doesn’t matter)
You call stage 3 rectal CA when?
tumor breaks out of the rectum and into the perirectal fat.
This is the critical stage that
changes management in Rectal CA (they will get chemo/rads prior to surgery).
Stage 3
High Rectal CA treatement
Low anterior Resection (LAR
- Will maintain fecal continence post op
Low Rectal CA treatment
Abdomino Perineal resection (APR)
- WIll end up with colonostomies
Surgical Treatment is classically determined by?
the position of the tumor relative to the butthole.
Both surgical approaches in rectal CA are performed with?
a total mesorectal excision (tumor, nodes, and blood supply).
The second most common tumor in the colon.
Lipomas
The most common benign tumor of the colon and rectum.
Adenoma
What type of colonic adenoma has the largest risk of malignancy?
Villous adenoma
villous adenoma classically causes what symtpom?
Mucous diarhhea = severe fluid and electrolyte depletion
old + diarhhea + electrolyte imbalance + bowel mass =
Villous adenoma
McKittrick-Wheelock Syndrome
VIllous adenoma
sigmoid colon sheds its oppressive mesentery and becomes the rectum at this level
S3
When does rectum become the anus?
15 cm after S3.
What part of teh rectium is retroperitoneal?
Proximal 1/3
What are the retroperitoneal structures?
Duodenum (2nd and 3rd)
Pancrease (head and body)
Colon (ascending and descending)
rectum (proximal 1/3)
The distal 1/3 of teh rectum is entirely….
Extraperitoneal