FAP Flashcards
Stem: You are discussing the results of a follow up colonoscopy with a young lady. She's very concerned because her father died of colon cancer at young age
Stem: You are discussing the results of a follow up colonoscopy with a young lady. She’s very concerned because her father died of colon cancer at young age
Q1: What can you see in this colonoscopy image?
Q.What’s the most probable diagnosis?
Q. Where else would you expect to find polyps other than colon and rectum?
Very large no. of polyps of different size and shape
FAP
Duodenum / Stomach
Q4: What’s the classification of intestinal polyps?
Q.Can you name a syndrome with hamartomatous polyp?
Q.Define a hamartoma?
Non-neoplastic – > Hamartoma / Metaplastic
Neoplastic – > Villous / Tubulovillious / Tubular
Inflammatory – > Pseaudopolyps / UC
– Peutez jugar Synd
Hamartoma; Focal collection of unorganized cells originally found at the same site of origin. It’s benign
Q3: can you name other inherited genetic colon cancer syndromes?
HNPCC (Lynch syndrome) –
Peutez jugar Synd-
Gardner Syndrome
Cowden syndrome
Q2: Define FAP? What’s the mood of inheritance? What’s the function of APC gene?
Familial aden. Plop its AD hereditary disorder which include hundreds of polyps in colon mainly by suppression of tumor suppressor gene “APC”
AD
APC; Adenoid polyposis coli
It’s tumor supp gene it encodes fx that -ve regulate WNT pathway in colon epithelium by promoting formation of a complex that degrades beta-catenin
Q10: What’s Gardener syndrome? Do you know other FAP variants?
A variant of FAP ch.ch by Desmoid tumor, osteomas and seb. cyst
APC Gene
Tarcot Syndrome – > brain tumor in addition to fap manifestation
Q5:What are their complications?
Malignant Transformation (Villious) /
Colon Obst. /
Volvolus /
Intussuption /
Bleeding /
infection /
Electrolyte imbalance
Q6:What are the features increasing the risk of malignant change in a polyp?
Type of Adenoma (Villous is more serious) / Diameter <1cm 5% , 2 cm 20% / Degree of dysplasia
Q7: Describe the sequence of events in malignant transformation of adenoma?
Adenoma-Carcinoma sequence
Hyperplasia due APC loss – > Dysplasia due to K-Ras mutation – > adenocarcinoma due P-53 loss
Q8: What’s a proto-oncogene, oncogene and tumor suppressor gene?
P; Normal genes they act like growth factors for cells
O; Mutation of proto-oncogene and they function autonomously cause uncontrolled growth of cancer cells
TSG; normal genes act as prevent proliferation of mutated DNA cells P53
Q9:What are the functions of KRAS, P53 genes?
K-Ras; The KRAS gene produces the K-Ras protein, which is part of the RAS/MAPK pathway, relaying signals for cell growth and differentiation. K-Ras acts as a switch, turned on by binding to GTP to transmit signals, and turned off when it converts GTP to GDP, which will stop signal transmission.
P53 (TSG); growth arrest, DNA repair and apoptosis (cell death)
Q12: Which life-style modifications would be beneficial in reducing cancer risk in patients with FAP?
Avoiding alcohol / smoking / decr. fat and incr. fiber rich diet
Q. Hyperplastic polyps?
Common type of polyps usually less than 5 mm, can occur in rectum or colon. Mostly don’t require reg. monitoring.
Q11: What are the different treatment modalities you would offer this lady with FAP? When?
-Pan proctocolectomy with IPAA (ileal pouch anal anastomosis )/ End ileostomy
-Proctocolectomy with ileo-anal anastomosis
-Colectomy with ileo-rectal anastomosis / ileostomy
at age of 25 yrs or earlier if there’re suspicion of malignancy
Q13: If she has a 2-year-old child, what would be your advice?
Genetic counselling / Flexible sigmoidoscopy at the age of 13 annually / at age of 20 do colonoscopy
and upper GI every 2 yrs
Q14: What’s endometriosis?
Presence of endometrial cells somewhere other than uterus in ectopic site.
