A 28-year-old woman presents to the emergency department with fever, chills, nausea, vomiting, and right flank pain for 2 days. Temperature is 39.2°C (102.6°F), blood pressure is 95/60 mmHg, pulse is 110/min, and respirations are 18/min. She appears ill and is unable to tolerate oral fluids. Physical examination shows right costovertebral angle tenderness. Urinalysis shows:
Protein 1+
Leukocyte esterase positive
Nitrite positive
RBC 2/hpf
WBC 90/hpf
WBC casts numerous
Which of the following is the most appropriate next step in management?
Q392
A 49-year-old man comes to the hospital for a 10-day history of cough and worsening shortness of breath. He has sharp right-sided chest pain that worsens on inspiration and coughing. Two weeks ago, the patient was admitted to the hospital after passing out on the street from alcohol intoxication but he left against medical advice. He has coronary artery disease and hypertension, and he does not take any medications. He drinks 4 cans of beer daily and has smoked 2 packs of cigarettes daily for 20 years. His temperature is 38.5°C (101.3° F), pulse is 110/min, respirations are 29/min, and blood pressure is 110/65 mmHg. Examination shows poor dentition. There is dullness to percussion at the base of the right lung. Crackles and markedly decreased breath sounds are heard over the right middle and lower lung fields. An x-ray of the chest shows a right-sided loculated pleural effusion and consolidation of the surrounding lung with visible air bronchogram; there are no rib fractures. Thoracocentesis is performed. Examination of this patient's pleural fluid is most likely to show which of the following findings?
Q393
A 65-year-old man presents to his primary care physician for fatigue. The patient states that he has not been sleeping well and requests sleep medication to help him with his fatigue. He recently changed his diet to try to increase his energy and has been on a vegetarian diet for the past several months. The patient has no significant past medical history. He smokes 1 pack of cigarettes per day and drinks 5 alcoholic beverages per day. The patient has lost 12 pounds since his last visit 1 month ago. Physical exam demonstrates a tired man. He appears thin, and his skin and sclera are icteric. Abdominal ultrasound is notable for a thin-walled and enlarged gallbladder. A urine sample is collected and is noted to be amber in color. Which of the following is the most likely diagnosis?
Q394
A 53-year-old woman presents to the office complaining of an extreme, nonradiating stabbing pain in the epigastric region after having a meal. She states that it has happened several times in the past week approximately 30 minutes after eating and spontaneously resolves. A day before, the patient went to urgent care with the same complaint, but the abdominal X-ray was normal. Surgical history is remarkable for a total knee arthroplasty procedure 6 months ago. She has lost 34 kg (75 lb) since the operation because of lifestyle changes. The vital signs are normal. Laparoscopic surgical scars are well healed. Endoscopy shows benign mucosa to the proximal duodenum. A barium swallow study reveals an extremely narrowed duodenum. Which of the following structures is most likely responsible for this patient’s current symptoms?
Q395
A 55-year-old man comes to the physician because of heartburn for the past 2 years. He has no chest pain, dysphagia, weight loss, or fever. He has no history of any serious illnesses. He takes omeprazole daily. Vital signs are within normal limits. Body mass index (BMI) is 34 kg/m2. Physical exam shows no abnormalities. An endoscopic image of the lower esophageal sphincter is shown. Which of the following is the most important next step in management?
Q396
A 48-year-old man presents to an urgent care center with epigastric discomfort following meals and an occasional dry cough worse in the morning, both of which have increased in frequency over the past several months. He is otherwise healthy and has no additional complaints. Past medical history is significant for major depressive disorder, anxiety, and hypothyroidism. Physical examination is unremarkable. His vital signs include temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 74/min, and respiratory rate 14/min. Given the following options, what is the most appropriate next step in patient management?
Q397
A 56-year-old man comes to the clinic complaining of intermittent abdominal pain for the past 2 months. He reports that the pain improves with oral intake and is concentrated at the epigastric area. The pain is described as gnawing in quality and improves when he takes his wife’s ranitidine. He denies weight changes, fever, chest pain, or recent travel but endorses “brain fog” and decreased libido. An upper endoscopy reveals ulcerations at the duodenum and jejunum. Physical examination demonstrates bilateral hemianopsia, gynecomastia, and diffuse pain upon palpation at the epigastric area. Laboratory findings are demonstrated below:
Serum:
Na+: 137 mEq/dL
Cl-: 96 mEq/L
K+: 3.9 mEq/dL
HCO3-: 25 mEq/L
Glucose: 110 mg/dL
Creatinine: .7 mg/dL
Ca2+: 13.5 mg/dL
What is the best explanation for this patient’s findings?
Q398
A 41-year-old man presents to the office with pain in his right big toe. The pain started yesterday and has been progressively getting worse to the point that it is difficult to walk. He describes his right big toe as being swollen and hot to the touch. He has never had symptoms like this before. He drinks 3 beers per night. Medical history is otherwise significant for chronic kidney disease. Physical examination is notable for an overweight gentleman in moderate pain, with an erythematous, swollen and tender right toe. He is afebrile. A joint fluid analysis in this patient is most likely to show what?
Q399
A 24-year-old man comes to the physician for a routine health maintenance examination. He feels well. He has type 1 diabetes mellitus. His only medication is insulin. He immigrated from Nepal 2 weeks ago . He lives in a shelter. He has smoked one pack of cigarettes daily for the past 5 years. He has not received any routine childhood vaccinations. The patient appears healthy and well nourished. He is 172 cm (5 ft 8 in) tall and weighs 68 kg (150 lb); BMI is 23 kg/m2. His temperature is 36.8°C (98.2°F), pulse is 72/min, and blood pressure is 123/82 mm Hg. Examination shows a healed scar over his right femur. The remainder of the examination shows no abnormalities. A purified protein derivative (PPD) skin test is performed. Three days later, an induration of 13 mm is noted. Which of the following is the most appropriate initial step in the management of this patient?
Q400
A 42-year-old man is brought to the emergency department by his wife because of a 1-day history of progressive confusion. He recently lost his job. He has a history of chronic alcoholism and has been drinking 14 beers daily for the past week. Before this time, he drank 6 beers daily. He appears lethargic. His vital signs are within normal limits. Serum studies show a sodium level of 111 mEq/L and a potassium level of 3.7 mEq/L. Urgent treatment for this patient's current condition increases his risk for which of the following adverse events?
Gastroenterology US Medical PG Practice Questions and MCQs
Question 391: A 28-year-old woman presents to the emergency department with fever, chills, nausea, vomiting, and right flank pain for 2 days. Temperature is 39.2°C (102.6°F), blood pressure is 95/60 mmHg, pulse is 110/min, and respirations are 18/min. She appears ill and is unable to tolerate oral fluids. Physical examination shows right costovertebral angle tenderness. Urinalysis shows:
Protein 1+
Leukocyte esterase positive
Nitrite positive
RBC 2/hpf
WBC 90/hpf
WBC casts numerous
Which of the following is the most appropriate next step in management?
A. Treat on an outpatient basis with ciprofloxacin
B. Wait for culture results and treat accordingly
C. Treat on an outpatient basis with nitrofurantoin
D. Admit the patient and perform a CT scan of the abdomen
E. Admit the patient and treat with intravenous levofloxacin (Correct Answer)
Explanation: ***Admit the patient and treat with intravenous levofloxacin***
- The presence of **WBC casts** is pathognomonic for **pyelonephritis**, an upper urinary tract infection.
- Given the severity indicated by **WBC casts** and significant **leukocyturia** (WBC 90/hpf), **inpatient management** with **intravenous antibiotics** (like levofloxacin) is appropriate to prevent progression to urosepsis.
*Treat on an outpatient basis with ciprofloxacin*
- While ciprofloxacin is an effective antibiotic for UTIs, **outpatient treatment** is generally not recommended for **severe pyelonephritis**, especially when WBC casts are present.
- This approach carries a higher risk of treatment failure and complications like **urosepsis** in severe cases.
*Wait for culture results and treat accordingly*
- Delaying treatment until culture results are available is inappropriate in a patient with signs of **acute pyelonephritis** (WBC casts, positive nitrite/leukocyte esterase, significant WBCs).
- Prompt initiation of **empiric antibiotics** is crucial to prevent rapid clinical deterioration and potential morbidity.
*Treat on an outpatient basis with nitrofurantoin*
- **Nitrofurantoin** primarily achieves therapeutic concentrations in the **lower urinary tract** and is not effective for treating **pyelonephritis** (upper UTI).
- Its use would lead to treatment failure and potential worsening of the infection due to inadequate drug delivery to the renal parenchyma.
*Admit the patient and perform a CT scan of the abdomen*
- While a **CT scan of the abdomen** may be considered later to evaluate for complications such as **abscess formation** or **obstruction**, the **immediate priority** is to initiate **antibiotic treatment** for acute pyelonephritis.
- Delaying antibiotic therapy in favor of imaging can lead to rapid clinical deterioration.
Question 392: A 49-year-old man comes to the hospital for a 10-day history of cough and worsening shortness of breath. He has sharp right-sided chest pain that worsens on inspiration and coughing. Two weeks ago, the patient was admitted to the hospital after passing out on the street from alcohol intoxication but he left against medical advice. He has coronary artery disease and hypertension, and he does not take any medications. He drinks 4 cans of beer daily and has smoked 2 packs of cigarettes daily for 20 years. His temperature is 38.5°C (101.3° F), pulse is 110/min, respirations are 29/min, and blood pressure is 110/65 mmHg. Examination shows poor dentition. There is dullness to percussion at the base of the right lung. Crackles and markedly decreased breath sounds are heard over the right middle and lower lung fields. An x-ray of the chest shows a right-sided loculated pleural effusion and consolidation of the surrounding lung with visible air bronchogram; there are no rib fractures. Thoracocentesis is performed. Examination of this patient's pleural fluid is most likely to show which of the following findings?
A. Lymphocytosis of > 90%
B. Pleural fluid LDH/serum LDH ratio of 0.5
C. Lactate dehydrogenase of 45 U/L
D. Amylase of 200 U/L
E. Glucose of 30 mg/dL (Correct Answer)
Explanation: ***Glucose of 30 mg/dL***
- This patient presents with symptoms and signs of a **parapneumonic effusion** that is likely complicated, given the **loculated pleural effusion** and **low pleural fluid glucose**. Alcoholism and poor dentition increase the risk of aspiration and subsequent bacterial pneumonia leading to empyema.
- A pleural fluid glucose level of **<60 mg/dL** (or significantly lower than serum glucose) is characteristic of a complicated parapneumonic effusion or empyema due to high metabolic activity by bacteria and local inflammatory cells.
*Lymphocytosis of > 90%*
- Marked pleural fluid **lymphocytosis** (>80-90% lymphocytes) is typically seen in **tuberculous pleurisy** or malignancy, not acute bacterial pneumonia with empyema.
- This patient's acute presentation, fever, and consolidation are not typical of tuberculosis, which usually has a more subacute or chronic course.
*Pleural fluid LDH/serum LDH ratio of 0.5*
- A pleural fluid LDH/serum LDH ratio >0.6 is one of **Light's criteria** for an exudative effusion, consistent with this patient's likely empyema. A ratio of 0.5 would make the effusion less definitively exudative by certain criteria alone.
- However, for complicated parapneumonic effusions or empyema, LDH levels in the pleural fluid are typically **very high** (>1000 U/L), making the ratio with serum LDH also high, usually >0.6.
*Lactate dehydrogenase of 45 U/L*
- A pleural fluid **LDH of 45 U/L** is a very low value, typically seen in a **transudative effusion** (e.g., heart failure, cirrhosis).
- Complicated parapneumonic effusions and empyema are exudative and characterized by **high pleural fluid LDH** due to inflammation and cell lysis, usually >1000 IU/L.
*Amylase of 200 U/L*
- Elevated pleural fluid **amylase** (often > normal serum level or > two times serum level) is suggestive of **pancreatitis**, **esophageal rupture**, or malignancy.
- While aspiration can sometimes involve pancreatic enzymes if gastric contents are aspirated, the primary clinical picture aligns with bacterial pneumonia and empyema, where amylase elevation is not a key diagnostic feature.
Question 393: A 65-year-old man presents to his primary care physician for fatigue. The patient states that he has not been sleeping well and requests sleep medication to help him with his fatigue. He recently changed his diet to try to increase his energy and has been on a vegetarian diet for the past several months. The patient has no significant past medical history. He smokes 1 pack of cigarettes per day and drinks 5 alcoholic beverages per day. The patient has lost 12 pounds since his last visit 1 month ago. Physical exam demonstrates a tired man. He appears thin, and his skin and sclera are icteric. Abdominal ultrasound is notable for a thin-walled and enlarged gallbladder. A urine sample is collected and is noted to be amber in color. Which of the following is the most likely diagnosis?
A. Cholangiocarcinoma
B. Pancreatic adenocarcinoma (Correct Answer)
C. Gallbladder adenocarcinoma
D. Iron deficiency anemia
E. Autoimmune hemolytic anemia
Explanation: ***Pancreatic adenocarcinoma***
- This patient presents with hallmark signs of **pancreatic adenocarcinoma**, including **painless jaundice** (icteric skin and sclera), **unexplained weight loss**, and risk factors such as **smoking** and **heavy alcohol use**.
- The abdominal ultrasound finding of a **thin-walled and enlarged gallbladder** in the setting of jaundice is known as **Courvoisier's sign**, highly suggestive of a distal biliary obstruction, often caused by a pancreatic head tumor.
*Cholangiocarcinoma*
- While cholangiocarcinoma can cause **obstruction and jaundice**, it is less commonly associated with **Courvoisier's sign** (distended, palpable gallbladder) compared to pancreatic head tumors.
- Risk factors for cholangiocarcinoma often include **primary sclerosing cholangitis** or **liver fluke infections**, which are not mentioned here.
*Gallbladder adenocarcinoma*
- Gallbladder adenocarcinoma often presents with **right upper quadrant pain**, **weight loss**, and sometimes **jaundice**, but the jaundice typically occurs later as the tumor invades the biliary tree.
- It is less likely to cause a **painless, distended gallbladder** (Courvoisier's sign) in the same way a pancreatic head mass would.
*Iron deficiency anemia*
- While fatigue can be a symptom of **iron deficiency anemia**, the striking features of **jaundice**, **weight loss**, and **Courvoisier's sign** point strongly away from this diagnosis as the primary cause of his symptoms.
- The dark urine in this context suggests **conjugated hyperbilirubinemia**, not typically seen in iron deficiency anemia.
*Autoimmune hemolytic anemia*
- **Autoimmune hemolytic anemia** can cause fatigue and **unconjugated hyperbilirubinemia**, leading to jaundice, but it would not explain the significant **weight loss**, **Courvoisier's sign**, or the amber (indicative of conjugated bilirubin) urine.
- The distended gallbladder points to an obstructive process rather than hemolytic jaundice.
Question 394: A 53-year-old woman presents to the office complaining of an extreme, nonradiating stabbing pain in the epigastric region after having a meal. She states that it has happened several times in the past week approximately 30 minutes after eating and spontaneously resolves. A day before, the patient went to urgent care with the same complaint, but the abdominal X-ray was normal. Surgical history is remarkable for a total knee arthroplasty procedure 6 months ago. She has lost 34 kg (75 lb) since the operation because of lifestyle changes. The vital signs are normal. Laparoscopic surgical scars are well healed. Endoscopy shows benign mucosa to the proximal duodenum. A barium swallow study reveals an extremely narrowed duodenum. Which of the following structures is most likely responsible for this patient’s current symptoms?
A. Superior mesenteric artery (Correct Answer)
B. Gastroduodenal artery
C. Inferior mesenteric artery
D. Gallbladder
E. Pylorus of the stomach
Explanation: ***Superior mesenteric artery***
- This patient's symptoms (postprandial epigastric pain, significant weight loss, and narrowed duodenum) are highly suggestive of **superior mesenteric artery (SMA) syndrome**. Weight loss can reduce the **mesenteric fat pad**, decreasing the angle between the SMA and the aorta, thereby compressing the third part of the duodenum.
- The narrow angle between the **aorta** and the **superior mesenteric artery** entraps the third portion of the duodenum, causing a functional obstruction, which explains the pain after meals when food distends the narrowed duodenum.
*Gastroduodenal artery*
- The gastroduodenal artery originates from the **common hepatic artery** and typically passes anterior to the duodenum, making it unlikely to cause compression.
- Compression by the gastroduodenal artery is not a recognized cause of **duodenal obstruction** or postprandial pain in this context.
*Inferior mesenteric artery*
- The **inferior mesenteric artery** supplies blood to the distal colon and rectum; its anatomical position is far from the duodenum.
- It does not cross or impinge upon the duodenum and therefore cannot cause **duodenal compression** or the described symptoms.
*Gallbladder*
- Gallbladder issues (e.g., **cholelithiasis**, **cholecystitis**) would typically cause **right upper quadrant pain**, possibly radiating to the back or shoulder, and often associated with fatty meals, but less likely to manifest as extreme epigastric pain 30 minutes post-meal with duodenal narrowing.
- The imaging findings of a narrowed duodenum and the pattern of pain are not characteristic of **gallbladder pathology**.
*Pylorus of the stomach*
- **Pyloric stenosis** would cause symptoms of gastric outlet obstruction, including **vomiting of undigested food**, early satiety, and weight loss, but the endoscopy showed benign mucosa to the proximal duodenum and the barium swallow revealed duodenal narrowing, not pyloric.
- While pyloric issues can cause postprandial symptoms, the **specific finding of a narrowed duodenum** points away from it as the primary cause in this case.
Question 395: A 55-year-old man comes to the physician because of heartburn for the past 2 years. He has no chest pain, dysphagia, weight loss, or fever. He has no history of any serious illnesses. He takes omeprazole daily. Vital signs are within normal limits. Body mass index (BMI) is 34 kg/m2. Physical exam shows no abnormalities. An endoscopic image of the lower esophageal sphincter is shown. Which of the following is the most important next step in management?
A. Endoscopic mucosal ablation therapy
B. Esophagectomy
C. High-dose pantoprazole
D. Multiple endoscopic biopsies (Correct Answer)
E. Laparoscopic Nissen fundoplication
Explanation: ***Multiple endoscopic biopsies***
- The endoscopic image likely shows **Barrett's esophagus**, characterized by metaplastic columnar epithelium. This condition is a precursor to **esophageal adenocarcinoma**.
- **Biopsies** are crucial to assess for the presence and grade of **dysplasia**, which dictates further management strategies.
*Endoscopic mucosal ablation therapy*
- This therapy is typically reserved for patients with **high-grade dysplasia** or **intramucosal carcinoma** in Barrett's esophagus, after diagnosis has been confirmed by biopsy.
- It would be premature to consider ablation without a definitive histological diagnosis of dysplasia.
*Esophagectomy*
- **Esophagectomy** is a major surgical procedure reserved for advanced esophageal cancer or high-grade dysplasia refractory to endoscopic therapies.
- It is an overly aggressive and inappropriate initial step without histological confirmation and assessment of dysplasia or cancer.
*High-dose pantoprazole*
- While proton pump inhibitors (PPIs) like pantoprazole are used to manage GERD symptoms and may help prevent progression of Barrett's esophagus, this patient is already on omeprazole daily.
- Simply increasing the dose of PPI does not address the need for **histological evaluation** of the abnormal-appearing mucosa for dysplasia or cancer.
*Laparoscopic Nissen fundoplication*
- This surgical procedure aims to strengthen the lower esophageal sphincter to treat severe GERD when medical management fails.
- While it addresses reflux, it does not directly evaluate or treat the potential **precancerous changes** in the esophageal lining seen on endoscopy, making biopsies a more immediate and critical next step.
Question 396: A 48-year-old man presents to an urgent care center with epigastric discomfort following meals and an occasional dry cough worse in the morning, both of which have increased in frequency over the past several months. He is otherwise healthy and has no additional complaints. Past medical history is significant for major depressive disorder, anxiety, and hypothyroidism. Physical examination is unremarkable. His vital signs include temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 74/min, and respiratory rate 14/min. Given the following options, what is the most appropriate next step in patient management?
A. Begin omeprazole therapy
B. Esophagogastroduodenoscopy (EGD) with esophageal biopsy
C. Electrocardiography (ECG)
D. Fluoroscopic barium swallow
E. Lifestyle modifications (Correct Answer)
Explanation: ***Lifestyle modifications***
- Given the patient's symptoms of **epigastric discomfort following meals** and **occasional dry cough worse in the morning**, which are suggestive of **gastroesophageal reflux disease (GERD)**, initial management often starts with lifestyle modifications.
- These include avoiding trigger foods, eating smaller meals, not lying down immediately after eating, and elevating the head of the bed, which can significantly reduce reflux symptoms.
*Begin omeprazole therapy*
- While omeprazole, a **proton pump inhibitor (PPI)**, is effective for GERD, it is generally considered after lifestyle modifications have been attempted or if symptoms are more severe or persistent, particularly in the absence of **alarm symptoms** (e.g., dysphagia, weight loss).
- Starting pharmacotherapy immediately without attempting lifestyle changes first is not usually the most appropriate initial step for uncomplicated GERD.
*Esophagogastroduodenoscopy (EGD) with esophageal biopsy*
- An EGD is typically reserved for patients with GERD who have **alarm symptoms** (e.g., dysphagia, odynophagia, weight loss, GI bleeding, anemia), persistent symptoms despite empiric PPI therapy, or risk factors for **Barrett's esophagus**.
- This patient has no alarm symptoms and can be managed conservatively first.
*Electrocardiography (ECG)*
- An ECG assesses **cardiac function** and is used to rule out cardiac causes of chest pain or epigastric discomfort, especially in patients with cardiac risk factors.
- However, the patient's primary symptoms of epigastric discomfort **post-meals** and a **morning cough** are highly suggestive of GERD, and he has no other complaints or risk factors pointing strongly towards cardiac issues, making an ECG less prioritized as the *initial* management step.
*Fluoroscopic barium swallow*
- A barium swallow is used to evaluate the **anatomy and function of the esophagus**, often to detect strictures, masses, or motility disorders.
- It is generally not the first-line diagnostic or management tool for typical GERD symptoms and has limited utility in diagnosing reflux itself compared to a trial of therapy or pH monitoring.
Question 397: A 56-year-old man comes to the clinic complaining of intermittent abdominal pain for the past 2 months. He reports that the pain improves with oral intake and is concentrated at the epigastric area. The pain is described as gnawing in quality and improves when he takes his wife’s ranitidine. He denies weight changes, fever, chest pain, or recent travel but endorses “brain fog” and decreased libido. An upper endoscopy reveals ulcerations at the duodenum and jejunum. Physical examination demonstrates bilateral hemianopsia, gynecomastia, and diffuse pain upon palpation at the epigastric area. Laboratory findings are demonstrated below:
Serum:
Na+: 137 mEq/dL
Cl-: 96 mEq/L
K+: 3.9 mEq/dL
HCO3-: 25 mEq/L
Glucose: 110 mg/dL
Creatinine: .7 mg/dL
Ca2+: 13.5 mg/dL
What is the best explanation for this patient’s findings?
A. Mutation of the RET gene
B. Mutation of the MEN1 gene (Correct Answer)
C. Infection with Helicobacter pylori
D. Gastrin secreting tumor of the pancreas
E. Mutation of the APC gene
Explanation: ***Mutation of the MEN1 gene***
- The patient presents with **recurrent peptic ulcers** (duodenal and jejunal), strongly suggesting **Zollinger-Ellison syndrome (ZES)**, hypercalcemia from **primary hyperparathyroidism**, and pituitary abnormalities (bilateral hemianopsia, decreased libido, gynecomastia suggestive of **prolactinoma** or other pituitary tumor). This classic triad (parathyroid, pituitary, pancreatic tumors) is characteristic of **Multiple Endocrine Neoplasia type 1 (MEN1)**, which is caused by a mutation in the *MEN1* gene.
- The **elevated serum calcium (13.5 mg/dL)** confirms **hyperparathyroidism**, and the description of ulcerations in the jejunum points towards aggressive acid hypersecretion seen in **Zollinger-Ellison Syndrome (ZES)**, often caused by a **gastrinoma** in the pancreas, as components of MEN1.
*Mutation of the RET gene*
- A mutation in the *RET* gene is associated with **Multiple Endocrine Neoplasia type 2 (MEN2)**.
- MEN2 typically involves **medullary thyroid carcinoma**, **pheochromocytoma**, and **primary hyperparathyroidism** (MEN2A) or **mucosal neuromas** (MEN2B), none of which are featured in this patient's presentation.
*Infection with Helicobacter pylori*
- *H. pylori* infection is a common cause of **peptic ulcers**, but it does not explain the patient's **hypercalcemia**, **pituitary symptoms** (bilateral hemianopsia, decreased libido, gynecomastia), or the presence of ulcers in the **jejunum**, which is highly suggestive of ZES.
- While it could contribute to gastric symptoms, it wouldn't account for the systemic endocrine abnormalities.
*Gastrin secreting tumor of the pancreas*
- A gastrin-secreting tumor (gastrinoma) in the pancreas causes **Zollinger-Ellison syndrome (ZES)**, leading to recurrent, severe peptic ulcers, as seen in this patient.
- While ZES is part of the clinical picture, this option only describes one component of the patient's multi-system endocrine disorder and doesn't explain the **hypercalcemia** or the **pituitary symptoms**.
*Mutation of the APC gene*
- A mutation in the *APC* gene is associated with **Familial Adenomatous Polyposis (FAP)**.
- FAP is characterized by hundreds to thousands of **colonic polyps** and an increased risk of **colorectal cancer**, which is unrelated to the patient's current symptoms involving ulcers, hypercalcemia, and pituitary issues.
Question 398: A 41-year-old man presents to the office with pain in his right big toe. The pain started yesterday and has been progressively getting worse to the point that it is difficult to walk. He describes his right big toe as being swollen and hot to the touch. He has never had symptoms like this before. He drinks 3 beers per night. Medical history is otherwise significant for chronic kidney disease. Physical examination is notable for an overweight gentleman in moderate pain, with an erythematous, swollen and tender right toe. He is afebrile. A joint fluid analysis in this patient is most likely to show what?
A. Positively birefringent crystals
B. Negatively birefringent crystals (Correct Answer)
C. Normal
D. Glucose < 40 mg/dL
E. Gram negative diplococci
Explanation: **Negatively birefringent crystals**
- The patient's presentation with acute, severe pain in the **first metatarsophalangeal joint (podagra)**, swelling, and erythema, coupled with a history of alcohol use and chronic kidney disease, is highly suggestive of **gout**.
- **Gout** is characterized by the deposition of **monosodium urate crystals** in joints, which appear as **negatively birefringent needle-shaped crystals** under polarized light microscopy in synovial fluid.
*Positively birefringent crystals*
- **Calcium pyrophosphate dihydrate (CPPD) crystals**, seen in **pseudogout**, are **positively birefringent** and rhomboid-shaped.
- Pseudogout typically affects larger joints like the knee and wrist, and while it presents acutely, the crystal morphology in this classic gout presentation rules it out.
*Normal*
- A normal synovial fluid analysis would not account for the patient's severe inflammatory symptoms and findings of **erythema, swelling, and tenderness**.
- This clinical presentation strongly indicates an underlying inflammatory arthropathy requiring specific diagnosis.
*Glucose < 40 mg/dL*
- A synovial fluid glucose level significantly lower than blood glucose (typically <50% of serum glucose or <40 mg/dL) is characteristic of **septic arthritis**.
- While septic arthritis can present with acute monoarthritis, this patient's presentation is more classic for gout, and there are no signs of systemic infection (e.g., fever).
*Gram negative diplococci*
- The presence of **Gram-negative diplococci** in synovial fluid is indicative of **gonococcal arthritis**, a form of septic arthritis.
- This patient's presentation lacks features typically associated with gonococcal infection, such as disseminated rash, tenosynovitis, or a history of sexually transmitted infections.
Question 399: A 24-year-old man comes to the physician for a routine health maintenance examination. He feels well. He has type 1 diabetes mellitus. His only medication is insulin. He immigrated from Nepal 2 weeks ago . He lives in a shelter. He has smoked one pack of cigarettes daily for the past 5 years. He has not received any routine childhood vaccinations. The patient appears healthy and well nourished. He is 172 cm (5 ft 8 in) tall and weighs 68 kg (150 lb); BMI is 23 kg/m2. His temperature is 36.8°C (98.2°F), pulse is 72/min, and blood pressure is 123/82 mm Hg. Examination shows a healed scar over his right femur. The remainder of the examination shows no abnormalities. A purified protein derivative (PPD) skin test is performed. Three days later, an induration of 13 mm is noted. Which of the following is the most appropriate initial step in the management of this patient?
A. Administer isoniazid for 9 months
B. Collect sputum sample for culture
C. Perform interferon-γ release assay
D. Obtain a chest x-ray (Correct Answer)
E. Perform PCR of the sputum
Explanation: ***Obtain a chest x-ray***
- A **positive PPD test** (13 mm induration in a patient with risk factors) indicates possible **latent tuberculosis infection (LTBI)**, but before initiating treatment, it's crucial to rule out **active tuberculosis (TB)**.
- A chest x-ray is the initial step to screen for signs of active disease, such as **infiltrates, cavitations**, or **lymphadenopathy**, which would necessitate a different treatment regimen than LTBI.
*Administer isoniazid for 9 months*
- This is a standard treatment for **LTBI**, but it should only be initiated after **active TB has been ruled out**.
- Treating active TB with LTBI monotherapy would be inadequate and could lead to **drug resistance**.
*Collect sputum sample for culture*
- **Sputum culture** is essential for diagnosing active pulmonary TB and for **drug susceptibility testing**, but it's typically performed *after* a chest x-ray suggests active disease.
- In a patient with a positive PPD and no symptoms, starting with sputum cultures without imaging is not the most appropriate first step.
*Perform interferon-γ release assay*
- **Interferon-γ release assays (IGRAs)**, such as QuantiFERON-TB Gold or T-Spot.TB, are alternative tests for detecting **M. tuberculosis infection**.
- While IGRAs can be used in place of or in conjunction with PPD, they also do not differentiate between latent and active infection, so a chest x-ray would still be required.
*Perform PCR of the sputum*
- **PCR (nucleic acid amplification test)** of sputum rapidly detects *M. tuberculosis* DNA and is a valuable tool for diagnosing **active TB**, especially in cases where rapid results are needed.
- However, like sputum culture, it is usually reserved for situations where there is a strong suspicion of active disease based on clinical symptoms or imaging findings.
Question 400: A 42-year-old man is brought to the emergency department by his wife because of a 1-day history of progressive confusion. He recently lost his job. He has a history of chronic alcoholism and has been drinking 14 beers daily for the past week. Before this time, he drank 6 beers daily. He appears lethargic. His vital signs are within normal limits. Serum studies show a sodium level of 111 mEq/L and a potassium level of 3.7 mEq/L. Urgent treatment for this patient's current condition increases his risk for which of the following adverse events?
A. Wernicke encephalopathy
B. Osmotic myelinolysis (Correct Answer)
C. Cerebral edema
D. Cardiac arrhythmia
E. Hyperglycemia
Explanation: ***Osmotic myelinolysis***
* **Rapid correction of severe hyponatremia** (serum sodium <120 mEq/L), especially when chronic, can cause **osmotic demyelination syndrome** (also known as central pontine myelinolysis).
* This condition results from a sudden shift in osmolality, causing water to leave brain cells, leading to neuronal damage and severe neurological deficits.
*Wernicke encephalopathy*
* **Wernicke encephalopathy** is caused by **thiamine deficiency**, common in chronic alcoholics.
* While he is at risk for Wernicke encephalopathy, the urgent treatment for his hyponatremia (rapid correction) is more likely to cause osmotic myelinolysis, not directly trigger Wernicke encephalopathy.
*Cerebral edema*
* **Cerebral edema** is a direct consequence of **severe, acute hyponatremia** (as fluid shifts into brain cells), not a risk of its *treatment*.
* The question asks about the risk of urgent treatment, which aims to *reduce* cerebral edema.
*Cardiac arrhythmia*
* While severe electrolyte imbalances can cause **cardiac arrhythmias**, the **rapid correction of hyponatremia** does not directly or primarily increase the risk of arrhythmias.
* The immediate risk associated with hyponatremia correction is neurological, related to osmotic shifts.
*Hyperglycemia*
* **Hyperglycemia** is a condition of high blood glucose and is not directly related to or caused by the **rapid correction of hyponatremia**.
* Although chronic alcohol abuse can affect glucose metabolism, hyperglycemia is not an acute adverse event of treating hyponatremia.
