A previously-healthy 24-year-old male is admitted to the intensive care unit following a motorcycle crash. He sustained head trauma requiring an emergency craniotomy, has burns over 30% of his body, and a fractured humerus. His pain is managed with a continuous fentanyl infusion. Two days after admission to the ICU he develops severe hematemesis. What is the PRIMARY mechanism underlying the development of his hematemesis?
Q302
A 56-year-old woman presents to her primary care physician complaining of heartburn, belching, and epigastric pain that is aggravated by coffee and fatty foods. She states that she has recently been having difficulty swallowing in addition to her usual symptoms. What is the most appropriate next step in management of this patient?
Q303
A 58-year-old man comes to the physician for recurrent heartburn for 12 years. He has also developed a cough for a year, which is worse at night. He has smoked a pack of cigarettes daily for 30 years. His only medication is an over-the-counter antacid. He has not seen a physician for 8 years. He is 175 cm (5 ft 9 in) tall and weighs 95 kg (209 lb); BMI is 31 kg/m2. Vital signs are within normal limits. There is no lymphadenopathy. The abdomen is soft and nontender. The remainder of the examination shows no abnormalities. A complete blood count is within the reference range. An upper endoscopy shows columnar epithelium 2 cm from the gastroesophageal junction. Biopsies from the columnar epithelium show low-grade dysplasia and intestinal metaplasia. Which of the following is the most appropriate next step in management?
Q304
A 24-year-old woman comes to the physician because of a 2-month history of increased urination. She has also had dry mouth and excessive thirst despite drinking several gallons of water daily. She has a history of obsessive-compulsive disorder treated with citalopram. She drinks 1–2 cans of beer daily. Physical examination shows no abnormalities. Serum studies show a Na+ concentration of 130 mEq/L, a glucose concentration of 185 mg/dL, and an osmolality of 265 mOsmol/kg. Urine osmolality is 230 mOsmol/kg. The patient is asked to stop drinking water for 3 hours. Following water restriction, repeated laboratory studies show a serum osmolality of 280 mOsmol/kg and a urine osmolality of 650 mOsmol/kg. Which of the following is the most likely diagnosis?
Q305
A 42-year-old man presents to his primary care physician for a wellness checkup. The patient has a past medical history of obesity, constipation, and depression. His current medications include metformin, lactulose, and fluoxetine. His temperature is 99.5°F (37.5°C), blood pressure is 157/102 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Laboratory values are ordered as seen below.
Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 5,500/mm^3 with normal differential
Platelet count: 190,000/mm^3
Serum:
Na+: 139 mEq/L
Cl-: 105 mEq/L
K+: 3.5 mEq/L
HCO3-: 21 mEq/L
BUN: 20 mg/dL
Glucose: 129 mg/dL
Creatinine: 1.1 mg/dL
AST: 12 U/L
ALT: 10 U/L
Urine:
Appearance: Yellow
Bacteria: Absent
Red blood cells: 0/hpf
pH: 6.8
Nitrite: Absent
Which of the following is the next best step in management?
Q306
A 24-year-old woman comes to the clinic complaining of headache and sinus drainage for the past 13 days. She reports cold-like symptoms 2 weeks ago that progressively got worse. The patient endorses subjective fever, congestion, sinus headache, cough, and chills. She claims that this is her 5th episode within the past year and is concerned if “there’s something else going on.” Her medical history is significant for asthma that is adequately controlled with her albuterol inhaler. Her laboratory findings are shown below:
Serum:
Hemoglobin: 16.2 g/dL
Hematocrit: 39 %
Leukocyte count: 7,890/mm^3 with normal differential
Platelet count: 200,000/mm^3
IgA: 54 mg/dL (Normal: 76-390 mg/dL)
IgE: 0 IU/mL (Normal: 0-380 IU/mL)
IgG: 470 mg/dL (Normal: 650-1500 mg/dL)
IgM: 29 mg/dL (Normal: 40-345 mg/dL)
What is the most likely diagnosis?
Q307
A 38-year-old woman is brought to the emergency department because of 3 1-hour episodes of severe, sharp, penetrating abdominal pain in the right upper quadrant. During these episodes, she had nausea and vomiting. She has no diarrhea, dysuria, or hematuria and is asymptomatic between episodes. She has hypertension and hyperlipidemia. Seven years ago, she underwent resection of the terminal ileum because of severe Crohn's disease. She is 155 cm (5 ft 2 in) tall and weighs 79 kg (175 lb). Her BMI is 32 kg/m2. Her temperature is 36.9°C (98.5°F), pulse is 80/min, and blood pressure is 130/95 mm Hg. There is mild scleral icterus. Cardiopulmonary examination shows no abnormalities. The abdomen is soft, and there is tenderness to palpation of the right upper quadrant without guarding or rebound. Bowel sounds are normal. The stool is brown, and a test for occult blood is negative. Laboratory studies show:
Laboratory test
Blood
Hemoglobin 12.5 g/dL
Leukocyte count 9,500 mm3
Platelet count 170,000 mm3
Serum
Total bilirubin 4.1 mg/dL
Alkaline phosphatase 348 U/L
AST 187 U/L
ALT 260 U/L
Abdominal ultrasonography shows a normal liver, a common bile duct caliber of 10 mm (normal < 6 mm), and gallbladder with multiple gallstones and no wall thickening or pericholecystic fluid. Which of the following is the most likely cause of these findings?
Q308
A 19-year-old college student is brought to the emergency department with persistent vomiting overnight. He spent all day drinking beer yesterday at a college party according to his friends. He appears to be in shock and when asked about vomiting, he says that he vomited up blood about an hour ago. At the hospital, his vomit contains streaks of blood. His temperature is 37°C (98.6°F), respirations are 15/min, pulse is 107/min, and blood pressure is 90/68 mm Hg. A physical examination is performed and is within normal limits. Intravenous fluids are started and a blood sample is drawn for typing and cross-matching. An immediate upper gastrointestinal endoscopy reveals a longitudinal mucosal tear in the distal esophagus. What is the most likely diagnosis?
Q309
A patient presents to the emergency department with abdominal pain. While having dinner, the patient experienced pain that prompted the patient to come to the emergency department. The patient states that the pain is episodic and radiates to the shoulder. The patient's temperature is 98°F (36.7°C), blood pressure is 120/80 mmHg, pulse is 80/min, respirations are 13/min, and oxygen saturation is 98% on room air. Laboratory values are ordered and return as below.
Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 4,500 cells/mm^3 with normal differential
Platelet count: 247,000/mm^3
Serum:
Na+: 140 mEq/L
Cl-: 100 mEq/L
K+: 4.6 mEq/L
HCO3-: 24 mEq/L
BUN: 15 mg/dL
Glucose: 90 mg/dL
Creatinine: 0.8 mg/dL
Ca2+: 10.0 mg/dL
AST: 11 U/L
ALT: 11 U/L
On physical exam, the patient demonstrates abdominal tenderness that is most prominent in the right upper quadrant. Which of the following represents the most likely demographics of this patient?
Q310
A 65-year-old man comes to the physician because of a 6-month history of muscle weakness. During this period, the patient has had low energy, intermittent nosebleeds, and a 5-kg (11-lb) weight loss. He also reports progressive hearing and vision problems. He has a history of pins-and-needles sensation, numbness, and pain in his feet. Vital signs are within normal limits. Physical examination shows a palpable liver tip 2–3 cm below the right costal margin. There is nontender lymphadenopathy in the groins, axillae, and neck. Laboratory studies show:
Hemoglobin 8.8 g/dL
White blood cells 6,300/mm3
Platelet count 98,000/mm3
Erythrocyte sedimentation rate 70 mm/h
Serum
Na+ 136 mmol/L
K+ 3.6 mmol/L
Cr 1.3 mg/dL
Ca2+ 8.6 mg/dL
Aspartate aminotransferase 32 U/L
Alanine aminotransferase 36 U/L
Alkaline phosphatase 100 U/L
Lactate dehydrogenase 120 U/L
A serum protein electrophoresis exhibits a sharp, narrow spike of monoclonal IgM immunoglobulin. Which of the following is the most likely diagnosis?
Gastroenterology US Medical PG Practice Questions and MCQs
Question 301: A previously-healthy 24-year-old male is admitted to the intensive care unit following a motorcycle crash. He sustained head trauma requiring an emergency craniotomy, has burns over 30% of his body, and a fractured humerus. His pain is managed with a continuous fentanyl infusion. Two days after admission to the ICU he develops severe hematemesis. What is the PRIMARY mechanism underlying the development of his hematemesis?
A. Fentanyl overuse
B. Increased gastric acid production
C. Helicobacter pylori infection
D. Direct mechanical trauma to the stomach
E. Decreased gastric blood flow (Correct Answer)
Explanation: ***Decreased gastric blood flow***
- This patient has **multiple severe injuries** including extensive **burns (30% body surface area)** and **head trauma**, both of which can cause stress ulcers.
- The PRIMARY mechanism in this critically ill patient is **gastric mucosal ischemia** due to **decreased gastric blood flow** from:
- **Hypovolemia and hypoperfusion** from extensive burns (Curling's ulcer)
- **Splanchnic vasoconstriction** in the stress response
- **Reduced mucosal protective mechanisms** due to ischemia
- While increased acid secretion contributes (especially from head trauma), the **mucosal ischemia** is the fundamental defect that allows ulceration to occur in stress ulcers.
- **Curling's ulcers** (burn-related) are classically associated with **mucosal ischemia** as the primary mechanism.
*Increased gastric acid production*
- **Cushing's ulcers** (associated with head trauma/CNS injury) do involve **increased gastric acid secretion** via vagal stimulation.
- However, this patient has **both burns and head trauma**, and the extent of burns (30% BSA) with associated hypoperfusion makes **decreased mucosal blood flow** the more critical primary mechanism.
- Increased acid production is a **contributing factor** but not the PRIMARY mechanism in this multi-trauma patient with extensive burns.
*Fentanyl overuse*
- Opioids like fentanyl can cause **constipation, nausea, and delayed gastric emptying** but do not directly cause gastric ulceration or hematemesis.
- Fentanyl does not increase gastric acid production or directly damage the gastric mucosa in a way that would lead to acute stress ulcers.
*Helicobacter pylori infection*
- **H. pylori** is a common cause of **chronic peptic ulcer disease** in the general population.
- In a **previously healthy 24-year-old** with acute hematemesis **2 days after severe trauma**, the timing and context strongly suggest **acute stress ulceration** rather than chronic H. pylori-related disease.
*Direct mechanical trauma to the stomach*
- The injuries described (head trauma, burns, fractured humerus) do not suggest **direct abdominal trauma** that would cause mechanical gastric injury.
- There is no mention of abdominal findings on the initial trauma assessment that would suggest gastric perforation or contusion.
- Hematemesis in this ICU setting is characteristic of **stress ulceration**, not mechanical trauma.
Question 302: A 56-year-old woman presents to her primary care physician complaining of heartburn, belching, and epigastric pain that is aggravated by coffee and fatty foods. She states that she has recently been having difficulty swallowing in addition to her usual symptoms. What is the most appropriate next step in management of this patient?
A. Trial of an H2 receptor antagonist
B. Trial of a proton pump inhibitor
C. Upper endoscopy (Correct Answer)
D. Nissen fundoplication
E. Lifestyle changes - don't lie down after eating; avoid spicy foods; eat small servings
Explanation: ***Upper endoscopy***
- The presence of **dysphagia** (difficulty swallowing) in a patient with chronic reflux symptoms is an **alarm symptom** that warrants immediate investigation to rule out serious conditions like **esophageal strictures** or **malignancy**.
- **Upper endoscopy** allows direct visualization of the esophagus, stomach, and duodenum, and enables biopsies if abnormalities are found.
*Trial of an H2 receptor antagonist*
- While H2 receptor antagonists can help manage reflux symptoms, they are generally prescribed for **mild to moderate GERD** without alarm symptoms.
- Starting this treatment without investigation could **delay diagnosis** of a potentially life-threatening condition given the dysphagia.
*Trial of a proton pump inhibitor*
- Proton pump inhibitors (PPIs) are highly effective for GERD symptoms and are often used as a first-line treatment for typical reflux.
- However, the presence of **dysphagia** is an **alarm symptom** that mandates further investigation with endoscopy before initiating or continuing empirical PPI therapy.
*Nissen fundoplication*
- **Nissen fundoplication** is a surgical procedure for severe GERD that is typically considered after **medical management has failed** and an **objective diagnosis** of GERD has been confirmed, often with endoscopy and pH monitoring.
- It is an **intervention**, not a diagnostic step, and would only be considered once the cause of dysphagia has been identified and ruled out for malignancy.
*Lifestyle changes - don't lie down after eating; avoid spicy foods; eat small servings*
- **Lifestyle modifications** are key components of GERD management and should be recommended to all patients with reflux symptoms.
- While beneficial, these changes alone are insufficient when an **alarm symptom** like dysphagia is present, as they would not address underlying structural issues or malignancy.
Question 303: A 58-year-old man comes to the physician for recurrent heartburn for 12 years. He has also developed a cough for a year, which is worse at night. He has smoked a pack of cigarettes daily for 30 years. His only medication is an over-the-counter antacid. He has not seen a physician for 8 years. He is 175 cm (5 ft 9 in) tall and weighs 95 kg (209 lb); BMI is 31 kg/m2. Vital signs are within normal limits. There is no lymphadenopathy. The abdomen is soft and nontender. The remainder of the examination shows no abnormalities. A complete blood count is within the reference range. An upper endoscopy shows columnar epithelium 2 cm from the gastroesophageal junction. Biopsies from the columnar epithelium show low-grade dysplasia and intestinal metaplasia. Which of the following is the most appropriate next step in management?
A. Endoscopic therapy (Correct Answer)
B. Nissen fundoplication
C. Repeat endoscopy in 18 months
D. External beam radiotherapy
E. Omeprazole, clarithromycin, and metronidazole therapy
Explanation: ***Endoscopic therapy***
- The presence of **low-grade dysplasia** and **intestinal metaplasia** in **Barrett's esophagus** significantly increases the risk of progression to high-grade dysplasia or esophageal adenocarcinoma. Endoscopic therapy, such as **endoscopic mucosal resection (EMR)** or **radiofrequency ablation (RFA)**, is recommended to eradicate the dysplastic tissue.
- This approach aims to prevent malignant transformation and has been shown to be more effective than surveillance alone for low-grade dysplasia.
*Nissen fundoplication*
- This is a **surgical procedure** primarily used to treat severe **gastroesophageal reflux disease (GERD)** symptoms that are refractory to medical management.
- While the patient has GERD, fundoplication does not directly address the **dysplastic changes** already identified in the esophageal lining and is not the primary treatment for dysplasia.
*Repeat endoscopy in 18 months*
- For **Barrett's esophagus without dysplasia**, surveillance endoscopy is typically performed every 3-5 years. For **low-grade dysplasia**, surveillance intervals are often shorter (e.g., 6-12 months) if immediate endoscopic therapy is not pursued or if there is uncertainty about the biopsy findings.
- However, with confirmed **low-grade dysplasia** and **intestinal metaplasia**, active eradication via endoscopic therapy is generally preferred over watchful waiting with delayed surveillance, given the risk of progression.
*External beam radiotherapy*
- **External beam radiotherapy** is a treatment for established **esophageal cancer**, not for precancerous conditions like low-grade dysplasia in Barrett's esophagus.
- It carries significant side effects and is overly aggressive for the current findings.
*Omeprazole, clarithromycin, and metronidazole therapy*
- This is a standard **triple therapy regimen** for eradicating **Helicobacter pylori infection**.
- While the patient has chronic GERD, there is no mention of H. pylori infection, and treating H. pylori would not resolve the **dysplastic changes** in the esophageal epithelium.
Question 304: A 24-year-old woman comes to the physician because of a 2-month history of increased urination. She has also had dry mouth and excessive thirst despite drinking several gallons of water daily. She has a history of obsessive-compulsive disorder treated with citalopram. She drinks 1–2 cans of beer daily. Physical examination shows no abnormalities. Serum studies show a Na+ concentration of 130 mEq/L, a glucose concentration of 185 mg/dL, and an osmolality of 265 mOsmol/kg. Urine osmolality is 230 mOsmol/kg. The patient is asked to stop drinking water for 3 hours. Following water restriction, repeated laboratory studies show a serum osmolality of 280 mOsmol/kg and a urine osmolality of 650 mOsmol/kg. Which of the following is the most likely diagnosis?
A. Nephrogenic diabetes insipidus
B. Beer potomania
C. Primary polydipsia (Correct Answer)
D. Primary hyperparathyroidism
E. Syndrome of inappropriate ADH secretion
Explanation: ***Primary polydipsia***
- The patient's initial laboratory values (low serum Na+, normal-to-low serum osmolality, and urine osmolality higher than serum) are consistent with **excessive water intake**.
- Following water restriction, the urine osmolality significantly increased (from 230 to 650 mOsmol/kg), indicating that the kidneys are able to concentrate urine normally when fluid intake is reduced, ruling out intrinsic renal defects or ADH deficiency.
*Nephrogenic diabetes insipidus*
- In **nephrogenic diabetes insipidus**, the kidneys are unable to respond to ADH, leading to consistently dilute urine even after water restriction.
- The marked increase in urine osmolality after water restriction rules out this diagnosis.
*Beer potomania*
- **Beer potomania** is a form of hyponatremia caused by excessive intake of beer, which is low in solutes, leading to water retention.
- While the patient drinks beer, her initial urine osmolality is not extremely low and her kidneys are able to concentrate urine effectively, which would not be the case if her polyuria was purely due to solute-free water excretion.
*Primary hyperparathyroidism*
- **Primary hyperparathyroidism** causes hypercalcemia, which can lead to nephrogenic diabetes insipidus secondary to calcium's effect on renal tubules.
- However, the patient's ability to concentrate urine after water restriction makes this unlikely to be the primary cause of her presenting symptoms.
*Syndrome of inappropriate ADH secretion*
- **SIADH** is characterized by euvolemic hyponatremia with inappropriately concentrated urine, typically due to excessive ADH secretion.
- The patient's symptoms of polyuria and polydipsia are inconsistent with SIADH, which usually presents with oliguria due to water retention.
Question 305: A 42-year-old man presents to his primary care physician for a wellness checkup. The patient has a past medical history of obesity, constipation, and depression. His current medications include metformin, lactulose, and fluoxetine. His temperature is 99.5°F (37.5°C), blood pressure is 157/102 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 98% on room air. Laboratory values are ordered as seen below.
Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 5,500/mm^3 with normal differential
Platelet count: 190,000/mm^3
Serum:
Na+: 139 mEq/L
Cl-: 105 mEq/L
K+: 3.5 mEq/L
HCO3-: 21 mEq/L
BUN: 20 mg/dL
Glucose: 129 mg/dL
Creatinine: 1.1 mg/dL
AST: 12 U/L
ALT: 10 U/L
Urine:
Appearance: Yellow
Bacteria: Absent
Red blood cells: 0/hpf
pH: 6.8
Nitrite: Absent
Which of the following is the next best step in management?
A. Administer ammonium chloride and repeat lab studies (Correct Answer)
B. Administer bicarbonate and repeat lab studies
C. Administer high dose bicarbonate
D. Obtain urine sodium level
E. Administer hydrochlorothiazide
Explanation: ***Administer ammonium chloride and repeat lab studies***
- The patient has **hypertension** (157/102 mmHg), **mild metabolic acidosis** (HCO3- 21 mEq/L), and **inappropriately alkaline urine pH (6.8)** despite systemic acidosis, suggesting **distal renal tubular acidosis (Type 1 RTA)**.
- In Type 1 RTA, the distal tubule cannot adequately secrete H+ ions, resulting in inability to acidify urine below pH 5.5 even in the presence of systemic acidosis.
- **Ammonium chloride loading test** is used to confirm Type 1 RTA by inducing metabolic acidosis and demonstrating the kidney's inability to lower urine pH below 5.5, establishing the diagnosis before initiating chronic alkali therapy.
*Administer hydrochlorothiazide*
- While the patient does have hypertension requiring treatment, hydrochlorothiazide is **not first-line therapy for Type 1 RTA** and can actually worsen hypokalemia, which is common in Type 1 RTA.
- Thiazide diuretics can exacerbate metabolic acidosis and do not address the underlying tubular defect in acid excretion.
- Treating hypertension is important but should occur after establishing the diagnosis of the acid-base disorder.
*Administer high dose bicarbonate*
- High-dose bicarbonate is the **chronic treatment** for Type 1 RTA, but the diagnosis must first be confirmed.
- Starting empiric bicarbonate therapy without diagnostic confirmation would obscure the diagnosis and prevent appropriate long-term management planning.
- The degree of acidosis is mild (HCO3- 21 mEq/L), so urgent bicarbonate administration is not required.
*Obtain urine sodium level*
- Urine sodium is useful for evaluating volume status, prerenal azotemia, or differentiating causes of acute kidney injury.
- It does not help diagnose or confirm renal tubular acidosis, which is the primary concern given the alkaline urine pH in the setting of metabolic acidosis.
*Administer bicarbonate and repeat lab studies*
- Simply administering bicarbonate and rechecking labs does not establish a diagnosis and would temporarily mask the acid-base abnormality.
- This approach would delay definitive diagnosis of Type 1 RTA and is not a systematic diagnostic strategy.
- Repeating labs without a diagnostic intervention provides no additional useful information.
Question 306: A 24-year-old woman comes to the clinic complaining of headache and sinus drainage for the past 13 days. She reports cold-like symptoms 2 weeks ago that progressively got worse. The patient endorses subjective fever, congestion, sinus headache, cough, and chills. She claims that this is her 5th episode within the past year and is concerned if “there’s something else going on.” Her medical history is significant for asthma that is adequately controlled with her albuterol inhaler. Her laboratory findings are shown below:
Serum:
Hemoglobin: 16.2 g/dL
Hematocrit: 39 %
Leukocyte count: 7,890/mm^3 with normal differential
Platelet count: 200,000/mm^3
IgA: 54 mg/dL (Normal: 76-390 mg/dL)
IgE: 0 IU/mL (Normal: 0-380 IU/mL)
IgG: 470 mg/dL (Normal: 650-1500 mg/dL)
IgM: 29 mg/dL (Normal: 40-345 mg/dL)
What is the most likely diagnosis?
A. Wiskott-Aldrich syndrome
B. Selective IgA deficiency
C. Common variable immunodeficiency (Correct Answer)
D. Ataxia-telangiectasia
E. X-linked agammaglobinemia
Explanation: ***Common variable immunodeficiency***
- This patient presents with recurrent sinopulmonary infections (5 episodes in the past year) and significantly **low levels of IgA, IgG, and IgM**, which is characteristic of **common variable immunodeficiency (CVID)**.
- CVID often manifests in adulthood (patient is 24) with infections, and laboratory findings typically show **decreased levels of at least two immunoglobulin classes**, most commonly IgG and IgA, with or without low IgM.
*Wiskott-Aldrich syndrome*
- This syndrome is characterized by the triad of **thrombocytopenia**, **eczema**, and **recurrent infections**, often presenting in early childhood.
- While recurrent infections are present, this patient does not have thrombocytopenia or eczema, and the immunoglobulin profile for Wiskott-Aldrich Syndrome typically shows **low IgM** with **normal to elevated IgA and IgE**.
*Selective IgA deficiency*
- This condition is defined by **isolated low IgA levels** (<7 mg/dL), with normal levels of IgG and IgM.
- This patient has low IgA, but also significantly low IgG and IgM, ruling out a selective IgA deficiency.
*Ataxia-telangiectasia*
- This is a rare, autosomal recessive disorder characterized by **ataxia**, **telangiectasias**, and **immunodeficiency** (often involving IgA and IgE, but can also affect IgG subclasses).
- The patient does not present with ataxia or telangiectasias, which are hallmark features of this syndrome.
*X-linked agammaglobinemia*
- This condition is almost exclusively found in **males** and typically presents with recurrent infections in **infancy** after maternal antibodies wane.
- It is characterized by **profoundly low or absent levels of all immunoglobulin classes** (IgG, IgA, IgM) and the **absence of B cells**, which is not entirely consistent with this female patient's presentation and immunoglobulin levels.
Question 307: A 38-year-old woman is brought to the emergency department because of 3 1-hour episodes of severe, sharp, penetrating abdominal pain in the right upper quadrant. During these episodes, she had nausea and vomiting. She has no diarrhea, dysuria, or hematuria and is asymptomatic between episodes. She has hypertension and hyperlipidemia. Seven years ago, she underwent resection of the terminal ileum because of severe Crohn's disease. She is 155 cm (5 ft 2 in) tall and weighs 79 kg (175 lb). Her BMI is 32 kg/m2. Her temperature is 36.9°C (98.5°F), pulse is 80/min, and blood pressure is 130/95 mm Hg. There is mild scleral icterus. Cardiopulmonary examination shows no abnormalities. The abdomen is soft, and there is tenderness to palpation of the right upper quadrant without guarding or rebound. Bowel sounds are normal. The stool is brown, and a test for occult blood is negative. Laboratory studies show:
Laboratory test
Blood
Hemoglobin 12.5 g/dL
Leukocyte count 9,500 mm3
Platelet count 170,000 mm3
Serum
Total bilirubin 4.1 mg/dL
Alkaline phosphatase 348 U/L
AST 187 U/L
ALT 260 U/L
Abdominal ultrasonography shows a normal liver, a common bile duct caliber of 10 mm (normal < 6 mm), and gallbladder with multiple gallstones and no wall thickening or pericholecystic fluid. Which of the following is the most likely cause of these findings?
A. Acute hepatitis A
B. Choledocholithiasis (Correct Answer)
C. Cholangitis
D. Pancreatitis
E. Cholecystitis
Explanation: ***Choledocholithiasis***
- The patient's presentation with **colicky right upper quadrant pain**, **nausea, and vomiting**, along with **scleral icterus** and abnormal liver function tests (elevated total bilirubin, ALP, AST, ALT), are classic signs of biliary obstruction.
- Abdominal ultrasonography showing **multiple gallstones** and a **dilated common bile duct (10 mm)** strongly suggests a stone lodged in the common bile duct, causing obstruction.
- The patient's history of **terminal ileum resection** for Crohn's disease is a risk factor for gallstone formation due to impaired bile salt reabsorption.
*Acute hepatitis A*
- While acute hepatitis A can cause elevated liver enzymes and jaundice, it typically presents with **malaise, fatigue, and diffuse abdominal discomfort**, not sharp, colicky RUQ pain.
- There would also be no evidence of **biliary duct dilation** or gallstones on ultrasound with hepatitis A.
*Cholangitis*
- Cholangitis is an infection of the bile ducts and presents with **Charcot's triad** (RUQ pain, fever, jaundice) or **Reynolds' pentad** (Charcot's triad plus altered mental status and hypotension).
- This patient does not have a fever, indicating the absence of cholangitis, although untreated choledocholithiasis can progress to cholangitis.
*Pancreatitis*
- Pancreatitis typically causes **epigastric pain** and is associated with significantly elevated lipase and amylase levels.
- While gallstones are a common cause of pancreatitis, the primary findings here point to biliary obstruction, and there's no mention of elevated pancreatic enzymes.
*Cholecystitis*
- Acute cholecystitis involves **inflammation of the gallbladder** and causes persistent right upper quadrant pain, often with **fever and leukocytosis**.
- Ultrasound findings typically include **gallbladder wall thickening**, pericholecystic fluid, and possibly a positive sonographic Murphy's sign, none of which are noted in this patient.
Question 308: A 19-year-old college student is brought to the emergency department with persistent vomiting overnight. He spent all day drinking beer yesterday at a college party according to his friends. He appears to be in shock and when asked about vomiting, he says that he vomited up blood about an hour ago. At the hospital, his vomit contains streaks of blood. His temperature is 37°C (98.6°F), respirations are 15/min, pulse is 107/min, and blood pressure is 90/68 mm Hg. A physical examination is performed and is within normal limits. Intravenous fluids are started and a blood sample is drawn for typing and cross-matching. An immediate upper gastrointestinal endoscopy reveals a longitudinal mucosal tear in the distal esophagus. What is the most likely diagnosis?
A. Esophageal candidiasis
B. Boerhaave syndrome
C. Mallory-Weiss tear (Correct Answer)
D. Pill esophagitis
E. Dieulafoy's lesion
Explanation: **Mallory-Weiss tear**
- The patient's history of **heavy alcohol consumption** followed by **persistent vomiting** leading to **hematemesis** (vomiting blood) is classic for a Mallory-Weiss tear.
- The endoscopic finding of a **longitudinal mucosal tear in the distal esophagus** confirms the diagnosis, as these tears are typically caused by sudden increases in intra-abdominal pressure during forceful vomiting.
*Esophageal candidiasis*
- This condition is typically seen in **immunocompromised individuals** (e.g., HIV/AIDS, transplant patients) or those with prolonged antibiotic use, none of which are suggested here.
- It presents with **dysphagia** and **odynophagia**, and endoscopy would show white plaques, not a mucosal tear.
*Boerhaave syndrome*
- This involves a **full-thickness rupture of the esophageal wall**, which is a much more severe condition than a Mallory-Weiss tear.
- While also caused by forceful vomiting, it typically presents with sudden, severe chest pain, subcutaneous emphysema, and high mortality, none of which are explicitly mentioned here, and the endoscopy shows only a mucosal tear.
*Pill esophagitis*
- This condition results from direct irritation of the esophageal mucosa by certain medications, especially if taken without sufficient water or while lying down.
- It usually presents with localized **chest pain** and **dysphagia**, and the patient's history does not suggest medication use as the cause.
*Dieulafoy's lesion*
- This is a rare cause of gastrointestinal bleeding characterized by an **abnormally large submucosal artery** that erodes through the mucosa, typically in the stomach.
- While it can cause hematemesis, it is not associated with forceful vomiting and the endoscopic finding of a longitudinal mucosal tear is not consistent with this diagnosis.
Question 309: A patient presents to the emergency department with abdominal pain. While having dinner, the patient experienced pain that prompted the patient to come to the emergency department. The patient states that the pain is episodic and radiates to the shoulder. The patient's temperature is 98°F (36.7°C), blood pressure is 120/80 mmHg, pulse is 80/min, respirations are 13/min, and oxygen saturation is 98% on room air. Laboratory values are ordered and return as below.
Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 4,500 cells/mm^3 with normal differential
Platelet count: 247,000/mm^3
Serum:
Na+: 140 mEq/L
Cl-: 100 mEq/L
K+: 4.6 mEq/L
HCO3-: 24 mEq/L
BUN: 15 mg/dL
Glucose: 90 mg/dL
Creatinine: 0.8 mg/dL
Ca2+: 10.0 mg/dL
AST: 11 U/L
ALT: 11 U/L
On physical exam, the patient demonstrates abdominal tenderness that is most prominent in the right upper quadrant. Which of the following represents the most likely demographics of this patient?
A. An elderly smoker with painless jaundice
B. A middle-aged male with a positive urea breath test
C. A middle-aged overweight mother (Correct Answer)
D. A middle-aged patient with a history of bowel surgery
E. An elderly diabetic with vascular claudication
Explanation: ***A middle-aged overweight mother***
- This patient's presentation of **episodic abdominal pain radiating to the shoulder**, specifically in the **right upper quadrant**, after a meal, strongly suggests **biliary colic** due to **gallstones**. The classic demographics for gallstones (cholelithiasis) are often summarized by the "5 F's": **Fat (overweight)**, **Fertile (multiparity)**, **Female**, **Forty (middle-aged)**, and **Family history**.
- The normal laboratory values (especially liver enzymes AST/ALT) and vital signs indicate that this is likely an uncomplicated case of biliary colic rather than a severe biliary infection like cholangitis or cholecystitis.
*An elderly smoker with painless jaundice*
- **Painless jaundice** in an **elderly smoker** is highly suggestive of **pancreatic cancer**, a very serious condition. While pancreatic cancer can cause abdominal pain, the pain is typically persistent, and jaundice would be present.
- This patient's laboratory values are normal, and there is no mention of jaundice, making this diagnosis less likely.
*A middle-aged male with a positive urea breath test*
- A **positive urea breath test** indicates an active **Helicobacter pylori (H. pylori)** infection, which is a common cause of peptic ulcers. While peptic ulcers cause epigastric pain, it's typically burning and relieved or worsened by food, and less commonly radiates to the shoulder in this specific episodic pattern.
- The patient's symptoms are more classic for biliary pain rather than peptic ulcer disease.
*A middle-aged patient with a history of bowel surgery*
- A **history of bowel surgery** increases the risk for conditions like **adhesions leading to bowel obstruction** or **incisional hernias**, which can cause episodic abdominal pain. However, this pain is usually crampy and diffuse, sometimes associated with vomiting and changes in bowel habits, and less likely to radiate specifically to the shoulder after eating.
- The localization to the right upper quadrant and shoulder radiation points away from a general bowel pathology.
*An elderly diabetic with vascular claudication*
- **Vascular claudication** refers to pain in the legs during activity due to peripheral artery disease. While being an **elderly diabetic** increases the risk for many health issues, including vascular problems, it doesn't directly explain abdominal pain radiating to the shoulder after a meal.
- Diabetes can lead to gastroparesis or other visceral neuropathies, but the symptoms described are more consistent with gallbladder issues.
Question 310: A 65-year-old man comes to the physician because of a 6-month history of muscle weakness. During this period, the patient has had low energy, intermittent nosebleeds, and a 5-kg (11-lb) weight loss. He also reports progressive hearing and vision problems. He has a history of pins-and-needles sensation, numbness, and pain in his feet. Vital signs are within normal limits. Physical examination shows a palpable liver tip 2–3 cm below the right costal margin. There is nontender lymphadenopathy in the groins, axillae, and neck. Laboratory studies show:
Hemoglobin 8.8 g/dL
White blood cells 6,300/mm3
Platelet count 98,000/mm3
Erythrocyte sedimentation rate 70 mm/h
Serum
Na+ 136 mmol/L
K+ 3.6 mmol/L
Cr 1.3 mg/dL
Ca2+ 8.6 mg/dL
Aspartate aminotransferase 32 U/L
Alanine aminotransferase 36 U/L
Alkaline phosphatase 100 U/L
Lactate dehydrogenase 120 U/L
A serum protein electrophoresis exhibits a sharp, narrow spike of monoclonal IgM immunoglobulin. Which of the following is the most likely diagnosis?
A. Waldenstrom macroglobulinemia (Correct Answer)
B. Mantle cell lymphoma
C. Multiple myeloma
D. Hairy cell leukemia
E. Monoclonal gammopathy of undetermined significance
Explanation: ***Waldenstrom macroglobulinemia***
- This condition is characterized by **monoclonal IgM gammopathy**, **anemia**, **fatigue**, **weight loss**, and **hyperviscosity symptoms** like nosebleeds, vision/hearing problems, and peripheral neuropathy. The palpable liver, lymphadenopathy, and elevated ESR further support this diagnosis.
- The patient's symptoms of **anemia** (low hemoglobin), **thrombocytopenia** (low platelets), and **organomegaly** (palpable liver, lymphadenopathy) are consistent with the lymphocytic infiltration of the bone marrow and other organs commonly seen in Waldenstrom macroglobulinemia.
*Mantle cell lymphoma*
- This is a B-cell lymphoma that typically presents with generalized **lymphadenopathy** and can involve the spleen and bone marrow.
- While it can cause systemic symptoms and cytopenias, the distinguishing feature of **monoclonal IgM gammopathy** is not characteristic of mantle cell lymphoma.
*Multiple myeloma*
- Multiple myeloma involves the overproduction of **monoclonal immunoglobulins**, typically **IgG or IgA**, and is characterized by bone pain, hypercalcemia, renal failure, and recurrent infections.
- While it can cause anemia and fatigue, the presence of a **monoclonal IgM spike** and hyperviscosity symptoms are inconsistent with multiple myeloma.
*Hairy cell leukemia*
- This is a **B-cell leukemia** characterized by the presence of "hairy cells" in the bone marrow and spleen, leading to **splenomegaly**, **pancytopenia**, and recurrent infections.
- While it causes pancytopenia and fatigue, the specific finding of a **monoclonal IgM gammopathy** and hyperviscosity symptoms are not typical features.
*Monoclonal gammopathy of undetermined significance*
- **MGUS** is a precursor condition characterized by a **monoclonal gammopathy** without evidence of end-organ damage or other features of plasma cell disorders.
- The patient's significant symptoms like **anemia**, **thrombocytopenia**, **weight loss**, **organomegaly**, and **hyperviscosity** indicate a malignant process beyond MGUS.