Repeated USMLE Questions Step 1 Review- 135- Pathology

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Q- A 62-year-old man with a history of chronic alcohol use presents with weight loss, epigastric pain, and jaundice. CT scan shows a mass in the head of pancreas.

Which tumor marker is most useful for this diagnosis?

A- Alpha-fetoprotein (AFP)

B- Cancer antigen 19-9 (CA 19-9)

C- Carcinoembryonic antigen (CEA)

D- Prostate-specific antigen (PSA)

B- Cancer antigen 19-9 (CA 19-9)- CA 19-9 is the most widely used tumor marker for pancreatic cancer. AFP is for hepatocellular carcinoma, PSA for prostate cancer, and CEA is less specific (colorectal, pancreatic, and gastric cancers).

 

Q- A 58-year-old man presented with abdominal pain and jaundice. Lab results show elevated conjugated bilirubin and alkaline phosphatase. A liver biopsy shows proliferation of bile ducts, fibrosis, and “onion-skin” appearance.

Which of the following is the most likely diagnosis?

A- Alcoholic cirrhosis

B- Autoimmune hepatitis

C- Primary biliary cholangitis

D- Primary sclerosing cholangitis

D- Primary sclerosing cholangitis- Primary sclerosing cholangitis (PSC) is characterized by bile duct fibrosis and “onion-skin” appearance. It is strongly associated with ulcerative colitis and p-ANCA positivity.

 

Q- A 40-year-old woman presents with a painless breast lump. Biopsy reveals malignant cells forming duct-like structures confined within the basement membrane.

Which of the following is the most likely diagnosis?

A- Ductal carcinoma in situ (DCIS)

B- Fibroadenoma

C- Invasive ductal carcinoma

D- Lobular carcinoma in situ (LCIS)

A- Ductal carcinoma in situ (DCIS)- DCIS is a non-invasive breast carcinoma confined to ducts without basement membrane invasion. Invasive ductal carcinoma shows invasion into the surrounding stroma.

 

Read this Pathology MCQs Book

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