Neoplasia USMLE Step 1 Practice Question
A 45-year-old man with a 10-year history of hepatitis B infection presents to the emergency department with a 3-week history of right upper quadrant pain and unintentional weight loss of 8 pounds. He denies fever, jaundice, or changes in stool color. Vital signs are stable: BP 130/84 mmHg, HR 92 bpm, RR 16/min, temp 36.8°C. On examination, the liver edge is palpable 3 cm below the right costal margin and is firm and nodular. Laboratory studies show: AST 95 U/L, ALT 88 U/L, total bilirubin 1.2 mg/dL, albumin 3.5 g/dL, prothrombin time normal. Alpha-fetoprotein (AFP) is 7,200 ng/mL. Abdominal ultrasound demonstrates a 4.8 cm heterogeneous mass with arterial phase enhancement in the right hepatic lobe. Which of the following best explains the aggressive biological behavior of this neoplasm?
Answer choices
- AActivation and amplification of TP53 and RB tumor suppressor pathways leading to enhanced cellular senescence
- BDownregulation of cyclin-dependent kinase inhibitors (p16/CDKN2A) with loss of G1/S checkpoint control
- CUpregulation of apoptotic pathways with increased sensitivity to programmed cell death
- DPreserved contact inhibition and maintenance of normal cell-cell adhesion molecules
- EReactivation of telomerase (TERT) with unlimited replicative potential and aneuploidyCorrect answer
- FActivation of DNA mismatch repair mechanisms with improved genomic stability
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