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. Author manuscript; available in PMC: 2020 Apr 9.
Published in final edited form as: Gastrointest Endosc. 2018 Nov 29;89(5):1056–1062. doi: 10.1016/j.gie.2018.11.027

TABLE 4.

An example of problem-based learning

A 68-year-old man with hypertension, diabetes mellitus type 2 and asthma was referred for a screening colonoscopy. The patient participated in an FIT-based national screening program for colorectal cancer. He had a positive test. His medication consists of metformin, digoxin, gliclazide, and antihypertensive medication.
During the colonoscopy, 6 polyps were removed. Polypectomy of a large polyp in the sigmoid colon led to arterial bleeding, which was stopped by using argon plasma coagulation and hemoclips. Histopathology showed tubular adenomas with low-grade dysplasia. Because there was a limited inspection of the distal colon due to the bleeding, a repeat colonoscopy was performed. During this colonoscopy, 5 additional polyps were removed, which were tubular adenomas with low-grade dysplasia. The patient was recommended to undergo surveillance colonoscopy at 1 year and 3 years after the index examination. Each examination showed additional tubular adenomas with low-grade dysplasia. Because of the large cumulative number of polyps, the patient was referred for genetic testing to rule out a polyposis syndrome. APC gene mutation and MUTYH gene mutation analyses results were negative.
Step 1. Clarification of unknown terms
 FIT: fecal immunochemical test
 APC: argon plasma coagulation: treatment for bleeding
 APC mutation: adenomatous polyposis coli gene mutation leading to an autosomal recessive polyposis syndrome
 MUTYH: a base excision repair gene that plays a significant role in detecting and protecting against oxidative DNA damage, leading to an autosomal recessive polyposis syndrome
Step 2. Questions raised by the case
 What are familial syndromes associated with the occurrence of colorectal cancer?
 What is the rationale of screening for colorectal cancer?
 How is a national screening program organized?
 What is FIT testing? What is the sensitivity and specificity of FIT?
 What is the risk of bleeding after polypectomy?
 What are risk factors for bleeding after polypectomy?
 How is post-polypectomy bleeding managed?
Step 3. Brainstorm
 National screening program: age 55–75 years, primary test: FIT every 2 years
 High specificity >90%
 Symptoms of colorectal cancer: Blood per rectum, anemia, fatigue, weight loss
 Adenomas with high-grade dysplasia turn into cancer sooner. Different mutations can lead to a higher grade of dysplasia or ingrowth of the tumor into deeper layers of the colon wall.
 Different types of adenomas: villous vs tubular adenoma. Pedunculated or sessile polyps
 Different classifications for histopathology and morphology
 Treatment of bleeding in this case: epinephrine, APC, hemostatic clips
 Hereditary causes for colorectal cancer: Different mutation pathways exist. APC gene, p53 gene mutations, familial syndromes: familial adenomatous polyposis, Lynch syndrome (hereditary nonpolyposis colorectal cancer)
 During the brainstorm, it was found that the trainees were already well-informed about the national screening program.
Step 4. Learning goals
 What are stages in progression of colorectal adenomas to colorectal cancer?
 What are the main genetic events in colorectal cancer progression?
 What are polyp factors associated with increased risk of progression to colorectal cancer?
 What are polyposis syndromes? What are the diagnostic criteria for attenuated familial adenomatous polyposis? What are the diagnostic criteria for MUTYH-associated polyposis?
 What are the possible adverse events of colonoscopy? What are risk factors for bleeding after polypectomy?
 How to manage post-polypectomy bleeding
Step 5. Clustering
 Three main topics: colorectal cancer progression, polyposis syndromes, and adverse events
Step 6. Individual research
 The mentor may provide advice regarding literature
 Trainees perform extensive searches and read the most relevant references
Step 7. Discussion
 Second meeting
 The learning goals are discussed
 After discussion, a new case is provided

FIT, Fecal immunochemical test.