A 62-year-old man comes to the office due to gnawing epigastric pain radiating to the back, which started 3 months ago and has become increasingly intense.  He has also experienced a 10-kg (22-lb) weight loss and yellowing of the eyes.  The patient has smoked 4 or 5 cigarettes a day for most of his life.  Vital signs are within normal limits.  The patient appears cachectic.  Examination shows scleral icterus.  The abdomen is tender to deep palpation.  Abdominal CT scan is shown in the image below:

This patient’s abdominal lesion most likely originated from which of the following?

A 32-year-old woman comes to the office due to postprandial abdominal pain and nausea.  The patient has no diarrhea, constipation, bloody stools, or vomiting.  Medical history is significant for rheumatoid arthritis.  The abdomen is mildly tender to palpation at the epigastrium but without distension or hepatosplenomegaly.  Laboratory studies reveal anemia.  A small gastric ulcer is seen during upper endoscopy, and biopsies are negative for Helicobacter pylori.  Biopsies of the duodenum reveal numerous intraepithelial lymphocytes, villous atrophy, and crypt hyperplasia.  Based on these biopsy findings, this patient is at increased risk for developing which of the following conditions later in life?

A 56-year-old man comes to the office for upper abdominal pain occurring with meals for the last month.  His symptoms improve when fasting.  The patient’s other medical problems are coronary artery disease and osteoarthritis.  His medications include aspirin, simvastatin, and acetaminophen as needed.  The patient drinks 1 or 2 beers daily but does not use tobacco or illicit drugs.  Upper endoscopy is performed and reveals a gastric ulcer with a smooth, rounded border and an exudative base.  A biopsy of the ulcer is taken and placed into a urea-containing solution that includes phenol red, a pH indicator.  Thirty minutes later, the solution has turned pink, indicating a pH increase.  This test result suggests that which of the following processes is occurring?

A 45-year-old man comes to the office due to fatigue, lack of sexual desire, and inability to maintain an erection.  A year ago, he was advised to lose weight with diet and exercise due to mildly elevated fasting glucose levels.  The patient has smoked a pack of cigarettes daily for the past 20 years and drinks an alcoholic beverage 3-4 times per month.  Blood pressure is 110/70 mm Hg and pulse is 65/min.  Oxygen saturation is 99% on room air.  BMI is 29 kg/m².  Skin examination shows increased pigmentation over the knuckles and face.  The liver is palpable 3-4 cm below the right costal margin.  The remainder of the examination reveals small testes.  Which of the following is most likely contributing to the development of the patient’s symptoms?

A 10-year-old boy is brought to the hospital for difficulty swallowing.  During dinner a few hours ago, a piece of chicken became stuck in the patient’s mid-chest region.  His parents say that he has previously had the sensation of food becoming stuck, but it has never lasted this long.  The patient has vomited multiple times, but the chicken has not dislodged.  Medical history is significant for eczema.  He is drooling and visibly uncomfortable.  An upper endoscopy is performed to remove the chicken from the esophagus, which exhibits multiple stacked, circular, ringlike indentations; linear furrowing; and scattered, small, whitish papules.  Which of the following findings is most likely to be seen on biopsy of this patient’s esophagus?

A 42-year-old man comes to the office due to progressive fatigue, nausea, and itchiness.  On review of systems, the patient admits that he occasionally has bloody stools.  Medical history is unremarkable.  Examination shows scleral icterus.  Percutaneous liver biopsy is performed, and histologic analysis of the tissue sample reveals fibrous obliteration of intrahepatic small bile ducts with concentric replacement by connective tissue.  Which of the following is the most likely diagnosis?

A 70-year old man comes to the office due to persistent aspiration.  Two weeks ago, he had a stroke that impacted his speech, voice, and swallowing.  Modified barium swallow study reveals aspiration of liquids without nasal regurgitation.  Aspiration is ameliorated when the patient flexes his neck to put his chin to his chest during swallowing.  This maneuver is most likely augmenting which of the following airway-protective mechanisms?

A 42-year-old man comes to the office due to leg swelling.  He has also had yellowing of the eyes and progressive abdominal distension for the past 3 weeks, as well as an associated 7-kg (15.4-lb) weight gain.  The patient drinks at least 8 beers a day and in the past has been admitted to the hospital for intoxication and seizures.  He denies smoking or intravenous drug use.  Vital signs are within normal limits.  Scleral icterus, spider angiomas, and palmar erythema are present.  There is no jugular venous distension, and cardiac auscultation reveals a normal rate and rhythm.  Breath sounds are normal.  The abdomen is diffusely enlarged, and a fluid wave is easily elicited.  Pitting edema is present in the bilateral lower extremities.  Which of the following pathophysiologic changes is most likely present in this patient?

An 80-year-old man comes to the office for evaluation of persistent dry mouth and difficulty chewing food.  He has had no dry eyes or joint pains.  The patient has no chronic medical conditions and takes no medications.  On examination, there is decreased saliva production but no tenderness or swelling of the salivary glands.  Extensive dental caries are present.  Laboratory results show negative anti-Ro/SSA and anti-La/SSB antibodies.  Which of the following age-related changes is most likely responsible for this patient’s symptoms?

An 80-year-old man participates in a study designed to evaluate the effects of aging on the liver.  He has undergone a liver biopsy every 10 years since age 40 so that researchers can identify age-related histologic changes.  The subject is healthy and has no relevant family history.  He does not use alcohol or illicit drugs.  BMI is 21.5 kg/m2.  Physical examination is unremarkable; laboratory studies, including complete blood count, liver function tests, cholesterol levels, and hemoglobin A1c, are within normal limits.  Which of the following histologic changes has most likely developed over time in this individual?

A 62-year-old man comes to the office for evaluation of abdominal swelling.  Over the last few weeks his abdomen has become more distended with associated mild discomfort and decreased appetite.  Past medical history includes multiple admissions for alcohol-induced pancreatitis.  The patient currently drinks 1 pint of liquor daily and does not use tobacco or illicit drugs.  Physical examination reveals mildly icteric sclera and multiple spider angiomas on the upper chest.  The abdomen is distended and there is dullness to percussion that changes location when the patient lays on either side.  Serum sodium is 130 mEq/dL and creatinine is 1.1 mg/dL.  Which of the following would most likely be seen in this patient?

An 87-year-old woman comes to the office to discuss treatment for colon cancer, which was recently diagnosed by colonoscopy.  CT scan was negative for metastatic disease.  The patient has no other medical conditions, and family history is unremarkable.  She does not drink alcohol.  Vital signs are normal.  A chemotherapy regimen containing a medication that is primarily metabolized by the liver is chosen for therapy.  Because of the patient’s age, the physician is considering adjusting the dose to prevent adverse effects.  Which of the following parameters is likely to be the most similar between this patient and a healthy 40-year-old individual?

A 45-year-old woman comes to the office due to a 6-month history of abdominal bloating, excessive flatulence, and watery diarrhea.  Past medical history is significant for long-standing type 1 diabetes mellitus managed with insulin.  Vital signs are normal.  Abdominal examination shows no abnormalities.  Jejunal aspirate is obtained during upper gastrointestinal endoscopy by placing a sterile catheter; culture of the aspirate reveals >10,000 colony-forming units/mL of Bacteroides species.  Which of the following is the most likely cause of this patient’s current symptoms?

A 46-year-old woman with a history of hiatal hernia and severe gastroesophageal reflux undergoes antireflux surgery.  The reflux symptoms were refractory to medical therapy, so an endoscopic fundoplication procedure is performed.  During surgery, the hiatal defect is repaired, and the gastric fundus is mobilized and wrapped around the lower esophagus to reinforce the lower esophageal sphincter.  No esophageal or gastric injuries occurred, but a neural structure traversing the esophageal hiatus of the diaphragm was inadvertently injured.  Which of the following is the most likely potential effect of this operative injury?

A 24-year-old, previously healthy woman comes to the emergency department due to hematemesis.  The patient was binge drinking when she became very nauseated and began vomiting repeatedly.  She reports vomiting approximately a cupful of bright red blood during the most recent episode.  Blood pressure is 136/78 mm Hg and pulse is 96/min.  Physical examination shows mild epigastric tenderness.  Endoscopy reveals a longitudinal mucosal laceration in the distal esophagus with active bleeding.  Endoscopic treatment is performed, but the bleeding recurs.  Angiography with transarterial embolization of the bleeding vessel is planned.  A distal branch of which of the following blood vessels is most likely to be embolized during this patient’s procedure?

A 74-year-old man comes to the office due to chronic constipation.  Bowel movements occur once every 3 days and are hard and pellet-like.  The patient frequently strains when he tries to defecate and never feels completely evacuated.  The constipation is occasionally so severe that he uses his fingers to remove stool from the anorectal vault.  Medical history is significant for Parkinson disease, for which he takes carbidopa-levodopa.  Vital signs are unremarkable.  A resting tremor is present on physical examination.  The abdomen is distended but nontender to palpation.  This patient’s condition is most likely due to inadequate relaxation of which of the following muscles during defecation?

A 4-day-old boy is brought to the office due to a 2-day history of progressive jaundice.  The patient was born at term following an uncomplicated pregnancy.  He is formula fed.  The patient and his mother are both blood group A, Rh-positive.  Vital signs are normal.  Examination shows scleral icterus and jaundice over the face and chest.  Laboratory results are as follows:

The patient is followed closely, and the jaundice resolves without intervention in 3 days.  This patient’s jaundice was most likely the result of which of the following changes in bilirubin metabolism compared to an adult?

A 67-year-old man comes to the office due to dark urine, pale-appearing stools, and progressive yellowing of his eyes over the last few weeks.  He also reports unintentional weight loss, but has had no night sweats, abdominal pain, bloody stools, or vomiting.  He has no chronic medical conditions and takes no medication.  Vital signs are within normal limits.  Scleral icterus is present.  The neck is supple.  No lymphadenopathy or skin abnormalities are present.  There is no hepatosplenomegaly.  Laboratory results are as follows:

CT scan of the abdomen reveals a pancreatic mass compressing the common bile duct and the pancreatic duct.  This patient’s disease process is most likely caused by a mutation affecting which of the following genes?