Ch. 13: LI Polyps, Tumors; Appendix

Question 1

Acute inflammation of the appendix (appendicitis) is the most common cause of ?
Obstruction of appendix – what causes it, in children? Adults
Most common symptoms?
Result of a rupture?
Common complication?
Neoplastic or non neoplastic accumulation of mucous in appendix, and if neoplastic, can cause?

Answer 1

acute abdomen 
Children – lymphoid hyperplasia
	Adults – fecalith 
Periumbilical pain, fever, nausea, pain in right     
     lower quadrant (mcburney)
Peritonitis with guarding and rebound tenderness
Periumbilical abscess
Mucocele- pseudomyxoma peritonei

Question 2

Two pathways to colorectal carcinoma?

Genes and sequence of the most common process of its development?

Answer 2

Adenoma- carcinoma (most common), microsatellite instability –
In the adenoma –carcinoma pathway, normal mucosa proceeds through an adenomatous precursor (APC), and terminates as an invasive carcinoma (p53 mutation).

Question 3

You have a pediatric patient with an acute abdomen and ascites; tapping the fluid reveals multiple gram negative organisms. You read on the patient’s chart that result of a recent kidney biopsy indicated diffuse effacement of the foot processes. What’s the ultimate cause of his acute abdomen?

Answer 3

Spontaneous bacterial peritonitis, resulting from nephrotic syndrome. If it’s an adult, probably it’s from cirrhosis and portal hypertension.

Question 4

You are treating an AIDS patient, who presents with malabsorption, GI bleeding, and obstruction. What virus would likely show up in a tissue biopsy?

Answer 4

HHV8 – Kaposi sarcoma of the GI – usually asymptomatic, can present with these symptoms.

Question 5

Your 50 pack year history of smoking patient presents with ascites, which you tap, and find malignant cells. What’s the origin and category of this disease?

Answer 5

Metastatic carcinoma, seeding of the peritoneum with malignant cells from the gastric, pancreatic, or ovarian tissues (most likely). You may be thinking lung cancer, but malignancies of those three organs are also smoking associated.

Question 6

Your patient presents with 1000’s of adenomatous colonic polyps upon resection of his bowel, and he describes the same findings in his brothers and sisters, as well as his father, upon consult.
What disorder does he have , gene responsible, prophylactic decision made by many sufferers, and result of not making this decision?

Answer 6

FAP – APC mutation (chromosome 5) – removal of colon and rectum – or he develops carcinoma by 40.

Question 7

What disorder does your patient have, if he develops FAP, a benign tumor of bone in the skull, and a non neoplastic fibroblast proliferation in the retroperitoneum (desmoids)

Answer 7

Gardner syndrome – FAP with fibromatosis and osteomas

Question 8

FAP with CNS tumors?

Answer 8

Turcot syndrome – medulloblastoma and glial tumors

Question 9

Your patient presents with a circumferential narrowing of the rectum – most common sign, risk factors, and how does it invade?

Answer 9

Adenocarcinoma of the rectum or sigmoid colon presents this way, and would present with fresh red blood in the stool, and the bleeding can cause iron deficiency anemia. Risk factors include age, prior colorectal cancer, ulcerative colitis, genetics, and diet. It invades lymphatic channels.

Question 10

Your patient has a left colon (rectosigmoid) colonic tumor resection. On microscopy, the specimen demonstrates a serrated edge, like a bread knife. The crypts are hyperplastic, with no evidence of dysplasia, and are elongated with cystic dilatations. What is this, and what is the likely outcome?

Answer 10

Hyperplastic GI polyp – benign, with no malignant potential.

Question 11

You resect a polyp from the colon of a patient, and it’s determined to be a tubular adenoma. What does it look like, what’s its prevalence among colonic adenomas, and what is the likely outcome?

Answer 11

Tubular adenoma – smooth surface lesions, closely packed epithelial tubules – dysplasia and carcinoma often develop. 2/3 of benign colonic adenomas, and if the dysplasia is confined to the polyp, it will likely not recur with resection.

Question 12

You resect a shaggy, cauliflower like polyp from a patient’s colon, and find thin, tall fingerlike processes, resembling the villi of the small intestines. What is this, what is the prevalence among colonic adenomas, and what malignant potential?

Answer 12

Villous adenoma – 1/3 of colonic adenomas, more frequently contain carcinoma foci.

Question 13

Describe the adenoma-carcinoma progression, related to adenomatous polyps.

Answer 13

First, you have a defective APC tumor suppressor gene, which can arise from a germline mutation (1 hit, on chromosome 5), or two spontaneous mutations. You have a KRAS mutation that allows the mutation to progress, and a failure of p53 to inhibit the progression to carcinoma. COX 2 must be elevated to proceed to carcinoma, which is why aspirin may be protective.