Chapter 33 WS Flashcards
two types of polyps found in the colon
Villous adenomas and Tubular adenomas
which type is most likely to become malignant? (Villous adenomas or Tubular adenomas)
villous adenomas
what is FAP and how is it treated?
The studding of the entire large bowel wall by thousands of polyps.
Treated by completely removing the colon and rectum.
what is HNPCC?
Hereditary nonpolyposis colorectal syndrome (Lynch syndrome).
Inherited disorder that greatly increases the risk of colorectal cancers due to repair gene mutations.
What are symptoms/clinical presentations of rectal cancer.
- Rectal bleeding
- change in bowel habits
- diarrhea versus constipation
- change in stool caliber
Distinguish between symptoms/clinical presentation of cancers of the left side of the colon versus the right
Left Side of Colon: blood in stool, change in stool caliber, obstructive symptoms, and abdominal pain
Right Side of Colon: abdominal pain often accompanied with an abdominal mass, nausea, vomiting, occult blood in stool.
an anterior extrarectal mass may be indicative of _______
peritoneal seeding
how do colorectal cancers spread to the supraclavicular lymph nodes
As a result of spread from metastatically involved paraaortic nodes via the thoracic duct.
What imaging studies are performed in the staging workup for colorectal cancer.
- Chest x-ray to detect mets to lungs,
- CT scan or MRI of pelvis to determine if tumor extends into other pelvic organs or lymph nodes,
- CT scan of abdomen to see if liver involved,
- PET to determine mets.
ascending colon: intraperitoneal or retroperitoneal?
retroperitoneal
descending colon: intraperitoneal or retroperitoneal?
retroperitoneal
cecum: intraperitoneal or retroperitoneal?
intraperitoneal
transverse colon: intraperitoneal or retroperitoneal?
intraperitoneal
sigmoid colon: intraperitoneal or retroperitoneal?
intraperitoneal
hepatic flexure: intraperitoneal or retroperitoneal?
retroperitoneal
splenic flexure: intraperitoneal or retroperitoneal?
retroperitoneal
define peritoneal seeding
Tumor cells break off and shed into the abdominal cavity then take up residence on another surface.
Tumor cells break off and shed into the abdominal cavity then take up residence on another surface.
peritoneal seeding
what is the main dose limiting structure when treating colorectal cancer
Small bowel
If treating the ascending or descending colon, then kidney is also a dose-limiting structure.
acute side effects of radiation to the colon
- diarrhea
- abdominal cramps and bloating
- proctitis
- bloody or mucus discharge
- dysuria
Also, leukopenia and thrombocytopenia. Chemoradiation increases gastrointestinal and hematologic toxicities. If perineum treated then moist desquamation can occur to this area.
chronic side effects of radiation to the colon
- Persistant diarrhea
- increased bowel frequency
- proctitis
- fistula
- urinary incontinence
- bladder atrophy.
Most common is enteritis, adhesions, and obstruction caused by damage to the small bowel.
What is the purpose of the surgeon placing clips during surgery for colorectal cancer.
To demarcate the tumor bed so radiation oncologist can more precisely outline the area at risk, thus using smaller treatment volumes
how does a full bladder change the location of the small bowel
pushes the small bowel more superiorly
What foods should patients avoid eating when being treated with radiation for colon cancer.
- whole grain breads or cereals
- fried or fatty foods
- milk and milk products
- raw vegetables
- fresh fruit.
what foods are recommended for patient being treated to the colon
- White bread,
- meat baked, broiled, or roasted until tender,
- macaroni,
- cooked vegetables
- peeled apples and bananas.
define dentate line of rectum
Also known as pectinate line. Divides the upper 2/3 and lower 1/3 of the anal canal. Line at which the cells transition from stratified squamous epithelium to columnar epithelium (cuboidal at dentate line)
define anal verge
The surface of the ringed opening of the anus. It is the lower edge of the anal canal that marks the junction of the anal canal and the external hair-bearing skin.
what are OARs
organs at risk
What are the OAR in the treatment for anal cancer.
- Femoral heads and neck,
- genitalia/perineum,
- small bowel,
- bladder.
define unresectable
tumor cannot be surgically removed
What are the two most important etiologic factors in the development of squamous cell carcinoma of the esophagus in Western countries.
excessive alcohol and tobacco use
At what vertebral body does the esophagus start and when does it terminate
starts at C6 and ends at T10/11
define barrett esophagus
A condition in which the distal esophagus is line with a columnar epithelium rather than a stratified squamous epithelium, usually due to gastroesophageal reflux. The cells undergo metaplasia.
A condition in which the distal esophagus is line with a columnar epithelium rather than a stratified squamous epithelium, usually due to gastroesophageal reflux. The cells undergo metaplasia.
barretts esophagus
define achalasia
A disorder in which the lower 2/3 region of the esophagus loses its normal peristaltic activity and prohibits the passage of food into the stomach