A 50-Year-Old Man Is Scheduled to Undergo a Colonoscopy for Routine

question 529

Multiple Choice

A 50-year-old man is scheduled to undergo a colonoscopy for routine colorectal cancer screening.  He has no abdominal pain, gross blood in the stool, constipation, change in stool caliber, or unintentional weight loss.  He also has no family history of colon cancer.  The procedure is uncomplicated, but the patient is found to have a small mucosal lesion (~1 cm) in his sigmoid colon.  The lesion is biopsied and its histology is shown in the image below. The pathogenesis of this patient's lesion most likely began with a mutation involving which of the following genes?

• A)APC
• B)DCC
• C)K-RAS
• D)MSH2
• E)p53

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Definitions:

Zero Coupon Bonds

Pay no coupons at all, but are offered at a substantial discount below their par value and hence provide capital appreciation rather than interest income. Sometimes referred to as “stripped bonds.”

Callable Bond

A bond that can be redeemed by the issuer before its maturity date at a specified call price.

Income Bonds

Bonds that pay interest only when the issuer has sufficient earnings, providing a variable income stream based on the issuer's profitability.

Yield to Maturity

The total return anticipated on a bond if it is held until the date it matures, reflecting interest and price appreciation.