Gastroenterology — MCQs

A 24-year-old woman presents with generalized edema, hematuria, and severe right-sided flank pain. Her vital signs are normal. A 24-hour urine collection shows >10 grams of protein in her urine. Serum LDH is markedly elevated. Contrast-enhanced spiral CT scan shows thrombosis of the right renal vein. Which of the following is the most likely mechanism behind this thrombosis?

An 81-year-old man is brought in by his neighbor with altered mental status. The patient's neighbor is unsure exactly how long he was alone, but estimates that it was at least 3 days. The neighbor says that the patient usually has his daughter at home to look after him but she had to go into the hospital recently. The patient is unable to provide any useful history. Past medical history is significant for long-standing hypercholesterolemia and hypertension, managed medically with rosuvastatin and hydrochlorothiazide, respectively. His vital signs include: blood pressure, 140/95 mm Hg; pulse, 106/min; temperature, 37.2°C (98.9°F); and respiratory rate, 19/min. On physical examination, the patient is confused and unable to respond to commands. His mucus membranes are dry and he has tenting of the skin. The remainder of the exam is unremarkable. Laboratory findings are significant for the following: Sodium 141 mEq/L Potassium 4.1 mEq/L Chloride 111 mEq/L Bicarbonate 21 mEq/L BUN 40 mg/dL Creatinine 1.4 mg/dL Glucose (fasting) 80 mg/dL Magnesium 1.9 mg/dL Calcium 9.3 mg/dL Phosphorous 3.6 mg/dL 24-hour urine collection Urine Sodium 169 mEq/24 hr (ref: 100–260 mEq/24 hr) Urine Creatinine 0.795 g/24 hr (ref: 1.0–1.6 g/24 hr) Which of the following is the most likely cause of this patient's acute renal failure?

A 67-year-old man presents to the emergency department with anxiety and trouble swallowing. He states that his symptoms have slowly been getting worse over the past year, and he now struggles to swallow liquids. He recently recovered from the flu. Review of systems is notable only for recent weight loss. The patient has a 33 pack-year smoking history and is a former alcoholic. Physical exam is notable for poor dental hygiene and foul breath. Which of the following is the most likely diagnosis?

A 58-year-old man comes to the clinic complaining of increased urinary frequency for the past 3 days. The patient reports that he has had to get up every few hours in the night to go to the bathroom, and says "whenever I feel the urge I have to go right away.” Past medical history is significant for a chlamydial infection in his twenties that was adequately treated. He endorses lower back pain and subjective warmth for the past 2 days. A rectal examination reveals a slightly enlarged prostate that is tender to palpation. What is the most likely explanation for this patient’s symptoms?

A 70-year-old man comes to the physician because of intermittent shortness of breath while going up stairs and walking his dog. It began about 1 month ago and seems to be getting worse. He has also developed a dry cough. He has not had any wheezing, fevers, chills, recent weight loss, or shortness of breath at rest. He has a history of Hodgkin lymphoma, for which he was treated with chemotherapy and radiation to the chest 7 years ago. He also has hypertension, for which he takes lisinopril. Ten years ago, he retired from work in the shipbuilding industry. He has smoked half a pack of cigarettes daily since the age of 21. Vital signs are within normal limits. On lung auscultation, there are mild bibasilar crackles. A plain x-ray of the chest shows bilateral ground-glass opacities at the lung bases and bilateral calcified pleural plaques. Which of the following is the greatest risk factor for this patient's current condition?

A 68-year-old woman comes to the physician because of increasing heartburn for the last few months. During this period, she has taken ranitidine several times a day without relief and has lost 10 kg (22 lbs). She has retrosternal pressure and burning with every meal. She has had heartburn for several years and took ranitidine as needed. She has hypertension. She has smoked one pack of cigarettes daily for the last 40 years and drinks one glass of wine occasionally. Other current medications include amlodipine and hydrochlorothiazide. She appears pale. Her height is 163 cm (5 ft 4 in), her weight is 75 kg (165 lbs), BMI is 27.5 kg/m2. Her temperature is 37.2°C (98.96°F), pulse is 78/min, and blood pressure is 135/80 mm Hg. Cardiovascular examination shows no abnormalities. Abdominal examination shows mild tenderness to palpation in the epigastric region. Bowel sounds are normal. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 10.2 g/dL Mean corpuscular volume 78 μm Mean corpuscular hemoglobin 23 pg/cell Leukocyte count 9,500/mm3 Platelet count 330,000/mm3 Serum Na+ 137 mEq/L K+ 3.8 mEq/L Cl- 100 mEq/L HCO3- 25 mEq/L Creatinine 1.2 mg/dL Lactate dehydrogenase 260 U/L Alanine aminotransferase 18 U/L Aspartate aminotransferase 15 U/L Lipase (N < 280 U/L) 40 U/L Troponin I (N < 0.1 ng/mL) 0.029 ng/mL An ECG shows normal sinus rhythm without ST-T changes. Which of the following is the most appropriate next step in the management of this patient?

A 27-year-old African American male presents to his family physician for “spots” on his foot. Yesterday, he noticed brown spots on his foot that have a whitish rim around them. The skin lesions are not painful, but he got particularly concerned when he found similar lesions on his penis that appear wet. He recalls having pain with urination for the last 4 weeks, but he did not seek medical attention until now. He also has joint pain in his right knee which started this week. He is sexually active with a new partner and uses condoms inconsistently. His physician prescribes a topical glucocorticoid to treat his lesions. Which of the following risk factors is most commonly implicated in the development of this condition?

A 20-year-old woman is brought to the emergency department by her parents after finding her seizing in her room at home. She has no known medical condition and this is her first witnessed seizure. She is stabilized in the emergency department. A detailed history reveals that the patient has been progressively calorie restricting for the past few years. Based on her last known height and weight, her body mass index (BMI) is 16.5 kg/m2. Which of the following electrolyte abnormalities would be of the most concern when this patient is reintroduced to food?

An 80-year-old woman presents with general malaise and low-grade fever. Physical examination reveals several retinal hemorrhages with pale centers, painless erythematous macules on palms and soles, and splinter hemorrhages under her fingernails. Echocardiogram shows vegetations on the mitral valve. Blood culture indicates gram-positive bacteria which are catalase negative and able to grow in 40% bile; however, not in 6.5% NaCl. In addition to endocarditis, the doctor is concerned that the patient may also be suffering from which of the following medical conditions?

A 26-year-old woman presents to the clinic today complaining of weakness and fatigue. She is a vegetarian and often struggles to maintain an adequate intake of non-animal based protein. She currently smokes 1 pack of cigarettes per day, drinks a glass of wine per day, and she currently denies any illicit drug use. Her past medical history is non-contributory. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 87/min, and respiratory rate 16/min. On physical examination, her pulses are bounding, the complexion is pale, the breath sounds are clear, and the heart sounds are normal. The spleen is mildly enlarged. She is at a healthy body mass index (BMI) of 22 kg/m2. The laboratory results indicate: mean corpuscular volume MCV: 71 fL, Hgb: 11.0, total iron-binding capacity (TIBC): 412 mcg/dL, transferrin saturation (TSAT): 11%. What is the most appropriate treatment for this patient?