A 47-year-old woman comes to the physician because of a 2-week history of gradually worsening facial and lower extremity swelling. She has had a 4-kg (8.8-lb) weight gain during this time. Her blood pressure is 150/88 mm Hg. Examination shows periorbital edema and 2+ pretibial edema bilaterally. A 24-hour collection of urine shows 4.0 g of proteinuria. Microscopic examination of a kidney biopsy specimen shows thickening of the glomerular basement membrane. Electron microscopy shows dense subepithelial deposits. Further evaluation is most likely to show which of the following?
Q382
A 72-year-old man presents to his primary care physician complaining of increasing difficulty sleeping over the last 3 months. He reports waking up frequently during the night because he feels an urge to move his legs, and he has a similar feeling when watching television before bed. The urge is relieved by walking around or rubbing his legs. The patient’s wife also notes that she sometimes sees him moving his legs in his sleep and is sometimes awoken by him. Due to his recent sleep troubles, the patient has started to drink more coffee throughout the day to stay awake and reports having up to 3 cups daily. The patient has a past medical history of hypertension and obesity but states that he has lost 10 pounds in the last 3 months without changing his lifestyle. He is currently on hydrochlorothiazide and a multivitamin. His last colonoscopy was when he turned 50, and he has a family history of type II diabetes and dementia. At this visit, his temperature is 99.1°F (37.3°C), blood pressure is 134/81 mmHg, pulse is 82/min, and respirations are 14/min. On exam, his sclerae are slightly pale. Cardiovascular and pulmonary exams are normal, and his abdomen is soft and nontender. Neurologic exam reveals 2+ reflexes in the bilateral patellae and 5/5 strength in all extremities. Which of the following is most likely to identify the underlying etiology of this patient's symptoms?
Q383
A 38-year-old man comes to the physician because of upper abdominal discomfort for 2 weeks. He has had 3–4 episodes of vomiting during this period. Over the last year, he has had frequent episodes of abdominal pain at night that were relieved by eating. He underwent a right shoulder surgery 6 weeks ago. He has no history of serious illness. He has smoked one pack of cigarettes daily for 14 years. He drinks one to two beers daily. He has a history of illicit drug use, but has not used for the past 15 years. He is sexually active with three female partners and uses condoms inconsistently. His only medication is daily naproxen. He returned from a 2-week vacation to Mexico one month ago. He appears uncomfortable. His temperature is 39.5°C (103.1°F), pulse is 90/min, and blood pressure is 110/70 mm Hg. Examination shows a soft abdomen with mild tenderness to palpation in the right upper quadrant. Bowel sounds are normal. Rectal examination is unremarkable. Test of the stool for occult blood is positive. His hemoglobin concentration is 13.1 g/dL, leukocyte count is 23,100/mm3, and platelet count is 230,000/mm3. Abdominal ultrasound shows a 2-cm hypoechoic lesion with some internal echoes in an otherwise normal looking liver. Which of the following is the most likely cause for the sonographic findings?
Q384
A 45-year-old woman comes to the physician's office with her 17-year-old daughter. She tells the physician that she developed Sjögren's syndrome when she was her daughter's age, and that she is concerned about her daughter developing the same condition. The girl appears to be in good health, with no signs or symptoms of the disease or pathology. Which of the following antibodies will most likely be positive if the woman's daughter were to develop Sjögren's syndrome?
Q385
A 40-year-old male presents to his primary care physician complaining of upper abdominal pain. He reports a four-month history of crampy epigastric pain that improves with meals. His past medical history is significant for hypertension that has been well controlled by lisinopril. He does not smoke and drinks alcohol occasionally. His family history is notable for a maternal uncle with acromegaly and a maternal grandfather with parathyroid adenoma requiring surgical resection. Based on clinical suspicion laboratory serum analysis is obtained and shows abnormal elevation of a peptide. This patient most likely has a mutation in which of the following chromosomes?
Q386
A 45-year-old male patient with a history of recurrent nephrolithiasis and chronic lower back pain presents to the ER with severe, sudden-onset, upper abdominal pain. The patient is febrile, hypotensive, and tachycardic, and is rushed to the OR for exploratory laparotomy. Surgery reveals that the patient has a perforated gastric ulcer. Despite appropriate therapy, the patient expires, and subsequent autopsy reveals multiple ulcers in the stomach, duodenum, and jejunum. The patient had been complaining of abdominal pain and diarrhea for several months but had only been taking ibuprofen for his lower back pain for the past 3 weeks. What is the most likely cause of the patient's presentation?
Q387
A 28-year-old man presents to his primary care provider complaining of intermittent stomach pain, non-bloody diarrhea, and weight loss for the last 3 months. He has occasional abdominal pain and fever. This condition makes studying difficult. He has tried omeprazole and dietary changes with no improvement. Past medical history is significant for occasional pain in the wrists and knees for several years. He takes ibuprofen for pain relief. His temperature is 38°C (100.4°F). On mental status examination, short-term memory is impaired. Attention and concentration are reduced. Examination shows no abnormalities or tenderness of the wrists or knees. There are no abnormalities on heart and lung examinations. Abdominal examination is normal. Upper endoscopy shows normal stomach mucosa but in the duodenum, there is pale yellow mucosa with erythema and ulcerations. Biopsies show infiltration of the lamina propria with periodic acid-Schiff (PAS)-positive macrophages. Which of the following best explains these findings?
Q388
A 38-year-old man comes to the emergency department because of epigastric pain and multiple episodes of vomiting for 4 hours. Initially, the vomit was yellowish in color, but after the first couple of episodes it was streaked with blood. He had 2 episodes of vomiting that contained streaks of frank blood on the way to the hospital. He has been hospitalized twice in the past year for acute pancreatitis. He drinks 2 pints of vodka daily but had over 4 pints during the past 12 hours. He takes naproxen for his 'hangovers.' He appears uncomfortable. His temperature is 37°C (99.1°F), pulse is 105/min, and blood pressure is 110/68 mm Hg. Examination shows dry mucous membranes and a tremor of his hands. The abdomen is soft and shows tenderness to palpation in the epigastric region; there is no organomegaly. Cardiopulmonary examination shows no abnormalities. Rectal examination is unremarkable. His hemoglobin concentration is 11.3 g/dL and hematocrit concentration is 40%. Which of the following is the most likely cause of this patient's findings?
Q389
A 13-year-old boy presents to the emergency department with severe abdominal pain. His parents state that he has been complaining of abdominal pain that became increasingly severe this evening. They also state he has been eating much more lately yet still has been losing weight. The patient's past medical history is unremarkable and he is not currently on any medications. His temperature is 99.5°F (37.5°C), blood pressure is 90/58 mmHg, pulse is 150/min, respirations are 24/min, and oxygen saturation is 98% on room air. Physical exam is notable for diffuse abdominal tenderness and tachycardia. Laboratory values are ordered as seen below.
Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 6,500/mm^3 with normal differential
Platelet count: 197,000/mm^3
Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.3 mEq/L
BUN: 20 mg/dL
Glucose: 599 mg/dL
Creatinine: 1.1 mg/dL
AST: 12 U/L
ALT: 10 U/L
Which of the following laboratory changes best reflects this patient's physiology as compared to his baseline?
Q390
A 67-year-old African American woman visits the clinic with a complaint of progressive fatigue. These symptoms started gradually and slowly became worse over the past 4 months. She is short of breath after walking a few blocks and has difficulty climbing stairs. She denies having chest pain, leg swelling, or a cough. Her past medical history is significant for osteoporosis and gastroesophageal reflux disease. She takes omeprazole as needed and daily baby aspirin. She is a retired accountant and is a lifetime nonsmoker but she drinks a small glass of red wine every night before bed. Her diet is varied. Today, her blood pressure is 128/72 mm Hg, heart rate is 105/min, respiratory rate is 22/min, temperature 37.0°C (98.6°F) and oxygen saturation is 94% on room air. On physical examination, she has marked conjunctival pallor. Cardiac auscultation reveals a rapid heartbeat with a regular rhythm and a 2/6 systolic murmur over the right upper sternal border. Lungs are clear to auscultation bilaterally and abdominal examination was within normal limits. Peripheral blood smear shows microcytic, hypochromic red blood cells. The following laboratory values are obtained:
Hematocrit 29%
Hemoglobin 9.8 mg/dL
Mean red blood cell volume 78 fL
Platelets 240,000/mm3
Which of the following will most likely be present in this patient?
Gastroenterology US Medical PG Practice Questions and MCQs
Question 381: A 47-year-old woman comes to the physician because of a 2-week history of gradually worsening facial and lower extremity swelling. She has had a 4-kg (8.8-lb) weight gain during this time. Her blood pressure is 150/88 mm Hg. Examination shows periorbital edema and 2+ pretibial edema bilaterally. A 24-hour collection of urine shows 4.0 g of proteinuria. Microscopic examination of a kidney biopsy specimen shows thickening of the glomerular basement membrane. Electron microscopy shows dense subepithelial deposits. Further evaluation is most likely to show which of the following?
A. Anti-myeloperoxidase antibodies
B. Anti-streptolysin O antibodies
C. Anti-phospholipase A2 receptor antibodies (Correct Answer)
D. Anti-C3 convertase antibodies
E. Anti-collagen type IV antibodies
Explanation: ***Anti-phospholipase A2 receptor antibodies***
- This patient's presentation with **nephrotic syndrome** (edema, hypertension, significant proteinuria) and kidney biopsy findings of **thickened glomerular basement membrane** with **subepithelial deposits** points to **membranous nephropathy**.
- **Anti-PLA2R antibodies** are a highly specific and common marker (found in 70-80% of cases) for **primary membranous nephropathy**, which is an autoimmune disease.
*Anti-myeloperoxidase antibodies*
- These antibodies are associated with **ANCA-associated vasculitides**, such as **microscopic polyangiitis** and **eosinophilic granulomatosis with polyangiitis (Churg-Strauss)**.
- These conditions typically present with **rapidly progressive glomerulonephritis** and rarely with isolated nephrotic syndrome or subepithelial deposits.
*Anti-streptolysin O antibodies*
- These antibodies are elevated after a **streptococcal infection** and are associated with **post-streptococcal glomerulonephritis**.
- This disease typically causes **nephritic syndrome** (hematuria, hypertension, mild proteinuria) and on biopsy shows **subepithelial humps** (immune complex deposits), but not a thick basement membrane as the primary finding.
*Anti-C3 convertase antibodies*
- These antibodies are characteristic of **C3 glomerulopathy**, which includes **dense deposit disease** (MPGN type II) and C3 glomerulonephritis.
- While C3 glomerulopathy can cause nephrotic syndrome, the characteristic electron microscopy findings are **intramembranous dense deposits**, not subepithelial deposits, and the primary defect is dysregulation of the alternative complement pathway.
*Anti-collagen type IV antibodies*
- These antibodies are characteristic of **Goodpasture syndrome** (anti-glomerular basement membrane disease).
- This condition typically presents with **rapidly progressive glomerulonephritis** and often **pulmonary hemorrhage**, and biopsy shows **linear deposition of IgG** along the glomerular basement membrane, not subepithelial deposits.
Question 382: A 72-year-old man presents to his primary care physician complaining of increasing difficulty sleeping over the last 3 months. He reports waking up frequently during the night because he feels an urge to move his legs, and he has a similar feeling when watching television before bed. The urge is relieved by walking around or rubbing his legs. The patient’s wife also notes that she sometimes sees him moving his legs in his sleep and is sometimes awoken by him. Due to his recent sleep troubles, the patient has started to drink more coffee throughout the day to stay awake and reports having up to 3 cups daily. The patient has a past medical history of hypertension and obesity but states that he has lost 10 pounds in the last 3 months without changing his lifestyle. He is currently on hydrochlorothiazide and a multivitamin. His last colonoscopy was when he turned 50, and he has a family history of type II diabetes and dementia. At this visit, his temperature is 99.1°F (37.3°C), blood pressure is 134/81 mmHg, pulse is 82/min, and respirations are 14/min. On exam, his sclerae are slightly pale. Cardiovascular and pulmonary exams are normal, and his abdomen is soft and nontender. Neurologic exam reveals 2+ reflexes in the bilateral patellae and 5/5 strength in all extremities. Which of the following is most likely to identify the underlying etiology of this patient's symptoms?
A. Colonoscopy (Correct Answer)
B. Trial of iron supplementation
C. Trial of reduction in caffeine intake
D. Trial of pramipexole
E. Dopamine uptake scan of the brain
Explanation: ***Colonoscopy***
- The patient presents with **classic restless legs syndrome (RLS)** symptoms along with multiple red flags: **unexplained 10-pound weight loss**, **pale sclerae** suggesting anemia, and a **remote last colonoscopy 22 years ago**.
- These findings raise significant concern for **gastrointestinal malignancy** (particularly colon cancer) causing chronic occult blood loss, leading to **iron deficiency anemia**, which is a well-known secondary cause of RLS.
- **Colonoscopy is the definitive diagnostic test** that would identify the underlying etiology (e.g., colon cancer, other GI bleeding source) causing the iron deficiency and subsequent RLS symptoms.
- At age 72 with the last colonoscopy at age 50, the patient is significantly overdue for colorectal cancer screening, making this investigation both urgent and appropriate.
*Trial of iron supplementation*
- While iron deficiency is likely contributing to the RLS symptoms, a **therapeutic trial does not identify the underlying etiology** - it only treats the consequence.
- Given the concerning red flags (weight loss, anemia, overdue screening), it would be premature to simply supplement iron without investigating the **source of iron loss**, which could be a malignancy.
- Iron supplementation may temporarily improve RLS but would delay diagnosis of a potentially serious underlying condition.
*Trial of reduction in caffeine intake*
- While caffeine can exacerbate RLS symptoms, the patient only increased coffee intake **after** developing sleep problems (as a compensatory mechanism).
- The presence of weight loss and anemia indicates a more serious underlying pathology that would not be addressed by reducing caffeine.
- Caffeine reduction alone would not identify any underlying etiology.
*Trial of pramipexole*
- Pramipexole is a **dopamine agonist** used for symptomatic treatment of RLS.
- However, it is important to **identify and treat secondary causes** (like iron deficiency from GI blood loss) before initiating dopaminergic therapy.
- This would be premature without first investigating the red flag symptoms suggesting serious underlying pathology.
*Dopamine uptake scan of the brain*
- A **DAT scan** is used to differentiate Parkinson's disease from essential tremor or other movement disorders, which is not relevant here.
- RLS is a **clinical diagnosis** based on symptoms, and dopamine imaging is not indicated for RLS diagnosis or workup.
- This test would not identify the underlying etiology of this patient's symptoms.
Question 383: A 38-year-old man comes to the physician because of upper abdominal discomfort for 2 weeks. He has had 3–4 episodes of vomiting during this period. Over the last year, he has had frequent episodes of abdominal pain at night that were relieved by eating. He underwent a right shoulder surgery 6 weeks ago. He has no history of serious illness. He has smoked one pack of cigarettes daily for 14 years. He drinks one to two beers daily. He has a history of illicit drug use, but has not used for the past 15 years. He is sexually active with three female partners and uses condoms inconsistently. His only medication is daily naproxen. He returned from a 2-week vacation to Mexico one month ago. He appears uncomfortable. His temperature is 39.5°C (103.1°F), pulse is 90/min, and blood pressure is 110/70 mm Hg. Examination shows a soft abdomen with mild tenderness to palpation in the right upper quadrant. Bowel sounds are normal. Rectal examination is unremarkable. Test of the stool for occult blood is positive. His hemoglobin concentration is 13.1 g/dL, leukocyte count is 23,100/mm3, and platelet count is 230,000/mm3. Abdominal ultrasound shows a 2-cm hypoechoic lesion with some internal echoes in an otherwise normal looking liver. Which of the following is the most likely cause for the sonographic findings?
A. Entamoeba histolytica (Correct Answer)
B. Penetrating duodenal ulcer
C. Echinococcus granulosus
D. Acute pancreatitis
E. Liver cancer
Explanation: ***Entamoeba histolytica***
- This patient's history of recent travel to Mexico, combined with fever, right upper quadrant pain, and a solitary hypoechoic liver lesion, strongly suggests an **amebic liver abscess** caused by *Entamoeba histolytica*.
- The elevated leukocyte count and positive occult blood in stool support an infectious inflammatory process, and the prior abdominal pain relieved by eating might indicate a pre-existing ulcer that facilitated a portal venous spread of the infection.
*Penetrating duodenal ulcer*
- While the patient has a history of abdominal pain relieved by eating, suggestive of a **duodenal ulcer**, a penetrating ulcer would more commonly present with localized peritonitis, severe acute pain, and potentially free air under the diaphragm which is not described.
- A penetrating ulcer wouldn't typically cause a defined hypoechoic liver lesion with internal echoes, but rather may cause severe inflammation or an abscess in adjacent structures.
*Echinococcus granulosus*
- **Hydatid cysts** from *Echinococcus granulosus* are typically **slow-growing**, asymptomatic for long periods, and generally appear as cystic lesions with daughter cysts or calcifications on ultrasound, not a single hypoechoic lesion with internal echoes and acute febrile illness.
- While travel to endemic areas increases risk, the acute presentation with fever and high white blood cell count makes an amebic abscess more likely.
*Acute pancreatitis*
- Acute pancreatitis usually causes severe epigastric pain radiating to the back, often with elevated lipase and amylase levels, which are not mentioned.
- While it can cause systemic inflammation and fever, the ultrasound finding of a **focal liver lesion** is not characteristic of acute pancreatitis, which primarily affects the pancreas itself.
*Liver cancer*
- While liver cancer (e.g., hepatocellular carcinoma) can present as a solitary liver lesion, the acute onset of fever, an elevated white blood cell count, and a recent travel history make an **infectious cause** far more likely than malignancy in this scenario.
- Liver cancer is typically a slow-growing disease, and while it can cause symptoms, an acute febrile illness with leukocytosis is less typical for its initial presentation.
Question 384: A 45-year-old woman comes to the physician's office with her 17-year-old daughter. She tells the physician that she developed Sjögren's syndrome when she was her daughter's age, and that she is concerned about her daughter developing the same condition. The girl appears to be in good health, with no signs or symptoms of the disease or pathology. Which of the following antibodies will most likely be positive if the woman's daughter were to develop Sjögren's syndrome?
A. Anti-dsDNA antibodies
B. Anti-histone antibodies
C. Anti-cyclic citrullinated antibodies
D. Anti-topoisomerase (anti-Scl 70) antibodies
E. Anti-SS-B (anti-La) antibodies (Correct Answer)
Explanation: ***Anti-SS-B (anti-La) antibodies***
- **Anti-SS-B (anti-La)** antibodies are highly specific for **Sjögren's syndrome** and are often found in conjunction with anti-SS-A (anti-Ro) antibodies.
- The presence of anti-SS-B antibodies supports a diagnosis of Sjögren's syndrome, particularly in patients with classic symptoms like **dry eyes** and **dry mouth**.
*Anti-dsDNA antibodies*
- **Anti-dsDNA antibodies** are most strongly associated with **systemic lupus erythematosus (SLE)**, particularly with lupus nephritis.
- They are not a primary diagnostic marker for Sjögren's syndrome, although some patients with Sjögren's may have secondary SLE.
*Anti-histone antibodies*
- **Anti-histone antibodies** are characteristic of **drug-induced lupus erythematosus**, though they can be present in other autoimmune diseases.
- They are not a specific marker for Sjögren's syndrome.
*Anti-cyclic citrullinated antibodies*
- **Anti-cyclic citrullinated peptides (anti-CCP) antibodies** are a sensitive and specific marker for **rheumatoid arthritis**.
- While Sjögren's and RA can coexist, anti-CCP antibodies are not indicative of Sjögren's syndrome itself.
*Anti-topoisomerase (anti-Scl 70) antibodies*
- **Anti-topoisomerase I (anti-Scl-70) antibodies** are specific for **systemic sclerosis (scleroderma)**, particularly the diffuse cutaneous form.
- They are not found in Sjögren's syndrome.
Question 385: A 40-year-old male presents to his primary care physician complaining of upper abdominal pain. He reports a four-month history of crampy epigastric pain that improves with meals. His past medical history is significant for hypertension that has been well controlled by lisinopril. He does not smoke and drinks alcohol occasionally. His family history is notable for a maternal uncle with acromegaly and a maternal grandfather with parathyroid adenoma requiring surgical resection. Based on clinical suspicion laboratory serum analysis is obtained and shows abnormal elevation of a peptide. This patient most likely has a mutation in which of the following chromosomes?
A. 13
B. 11 (Correct Answer)
C. 5
D. 10
E. 17
Explanation: ***Correct: 11***
- The patient's symptoms (epigastric pain improving with meals) suggest **peptic ulcer disease**, likely from a **gastrinoma** (Zollinger-Ellison syndrome)
- The family history of **acromegaly** (pituitary adenoma) and **parathyroid adenoma** strongly suggests **Multiple Endocrine Neoplasia type 1 (MEN1)** syndrome
- **MEN1** is caused by a germline mutation in the *MEN1* tumor suppressor gene located on **chromosome 11q13**
- MEN1 is characterized by the classic triad: **parathyroid** tumors, **pituitary** tumors, and **pancreatic endocrine** tumors (including gastrinomas)
- The elevated peptide mentioned is likely **gastrin**, produced by the pancreatic gastrinoma
*Incorrect: 13*
- Chromosome 13 mutations are associated with **Retinoblastoma** (*RB1* gene) and **Wilson's disease** (*ATP7B* gene)
- These conditions do not present with the combination of peptic ulcer disease and family history of endocrine tumors seen in this patient
*Incorrect: 5*
- Chromosome 5 mutations are linked to **Familial Adenomatous Polyposis (FAP)** due to *APC* gene mutation
- FAP presents with colonic polyps and increased colorectal cancer risk, not the endocrine manifestations described here
*Incorrect: 10*
- Chromosome 10 mutations are associated with **Multiple Endocrine Neoplasia type 2 (MEN2)** via the *RET* proto-oncogene
- **MEN2** typically involves **medullary thyroid carcinoma**, **pheochromocytoma**, and hyperparathyroidism, but NOT pituitary tumors or acromegaly
- The family history of acromegaly excludes MEN2 and points to MEN1
*Incorrect: 17*
- Chromosome 17 mutations are associated with **Neurofibromatosis type 1** (*NF1* gene) and **Li-Fraumeni syndrome** (*TP53* gene)
- These conditions present with neurofibromas, café-au-lait spots, or multiple cancers, not the endocrine tumor pattern seen in this patient
Question 386: A 45-year-old male patient with a history of recurrent nephrolithiasis and chronic lower back pain presents to the ER with severe, sudden-onset, upper abdominal pain. The patient is febrile, hypotensive, and tachycardic, and is rushed to the OR for exploratory laparotomy. Surgery reveals that the patient has a perforated gastric ulcer. Despite appropriate therapy, the patient expires, and subsequent autopsy reveals multiple ulcers in the stomach, duodenum, and jejunum. The patient had been complaining of abdominal pain and diarrhea for several months but had only been taking ibuprofen for his lower back pain for the past 3 weeks. What is the most likely cause of the patient's presentation?
A. H. pylori infection
B. Cytomegalovirus infection
C. A vasoactive-intestinal-peptide (VIP) secreting tumor of the pancreas
D. Chronic NSAID use
E. A gastrin-secreting tumor of the pancreas (Correct Answer)
Explanation: ***A gastrin-secreting tumor of the pancreas***
- The patient's presentation with **multiple ulcers** in the stomach, duodenum, and jejunum, along with **recurrent nephrolithiasis** (often associated with hypercalcemia), and chronic diarrhea, is highly indicative of **Zollinger-Ellison syndrome (ZES)**, which is caused by a gastrin-secreting neuroendocrine tumor (gastrinoma).
- The **severe, sudden-onset upper abdominal pain** and **perforated gastric ulcer** are acute complications of the excessive acid production seen in ZES, which can overwhelm protective mucosal mechanisms.
*H. pylori infection*
- While H. pylori is a common cause of **gastric and duodenal ulcers**, it typically doesn't lead to multiple ulcers extending into the **jejunum**, nor is it directly associated with **recurrent nephrolithiasis**.
- The widespread ulceration and association with chronic diarrhea and recurrent kidney stones strongly suggest a more systemic or diffuse etiology than typical H. pylori infection.
*Cytomegalovirus infection*
- CMV can cause **gastric or intestinal ulcers**, particularly in **immunocompromised individuals**, but it rarely causes multiple ulcers throughout the upper GI tract, including the jejunum, in an otherwise healthy individual.
- CMV infection is not typically associated with **recurrent nephrolithiasis** or the clinical picture of severe **acid overproduction**.
*A vasoactive-intestinal-peptide (VIP) secreting tumor of the pancreas*
- A **VIPoma** primarily causes **severe watery diarrhea** (pancreatic cholera) and **hypokalemia**, often without significant acidosis.
- It typically does not cause **multiple, widespread peptic ulcers** or **recurrent nephrolithiasis**, which are hallmarks of the patient's presentation.
*Chronic NSAID use*
- **NSAID use** can cause **gastric and duodenal ulcers**, and the patient had been taking ibuprofen for 3 weeks. However, the presence of **multiple ulcers** extending into the **jejunum** and the history of **recurrent nephrolithiasis** predating recent NSAID use point away from NSAID use as the primary cause.
- The severity and distribution of ulcers, along with the patient's history, are more consistent with a condition causing chronic, widespread acid hypersecretion rather than NSAID-induced injury.
Question 387: A 28-year-old man presents to his primary care provider complaining of intermittent stomach pain, non-bloody diarrhea, and weight loss for the last 3 months. He has occasional abdominal pain and fever. This condition makes studying difficult. He has tried omeprazole and dietary changes with no improvement. Past medical history is significant for occasional pain in the wrists and knees for several years. He takes ibuprofen for pain relief. His temperature is 38°C (100.4°F). On mental status examination, short-term memory is impaired. Attention and concentration are reduced. Examination shows no abnormalities or tenderness of the wrists or knees. There are no abnormalities on heart and lung examinations. Abdominal examination is normal. Upper endoscopy shows normal stomach mucosa but in the duodenum, there is pale yellow mucosa with erythema and ulcerations. Biopsies show infiltration of the lamina propria with periodic acid-Schiff (PAS)-positive macrophages. Which of the following best explains these findings?
A. Wilson’s disease
B. Celiac disease
C. Giardia lamblia infection
D. Whipple’s disease (Correct Answer)
E. Crohn’s disease
Explanation: ***Whipple’s disease***
- The combination of **gastrointestinal symptoms** (diarrhea, weight loss, abdominal pain) with **arthralgia**, **fever**, **neurological symptoms** (impaired short-term memory, reduced attention/concentration), and **PAS-positive macrophages** in duodenal biopsies is highly characteristic of Whipple's disease.
- This multisystemic bacterial infection, caused by *Tropheryma whipplei*, often presents with diverse, non-specific symptoms before the classic GI findings, and central nervous system involvement is common.
*Wilson’s disease*
- This is a disorder of **copper metabolism** leading to copper accumulation in organs like the liver, brain, and eyes (Kayser-Fleischer rings).
- While it can cause neurological symptoms and liver disease, the GI and biopsy findings (PAS-positive macrophages) are not consistent with Wilson's disease.
*Celiac disease*
- Characterized by **malabsorption** due to an immune reaction to gluten, presenting with diarrhea, weight loss, and abdominal pain.
- However, jejunal biopsies would show **villous atrophy** and crypt hyperplasia, not PAS-positive macrophages, and neurological findings are less common and typically peripheral in nature.
*Giardia lamblia infection*
- This parasitic infection causes **diarrhea**, abdominal cramps, and malabsorption.
- Diagnosis is usually made by identifying **trophozoites or cysts** in stool samples or duodenal aspirates/biopsies, not PAS-positive macrophages.
*Crohn’s disease*
- An **inflammatory bowel disease** characterized by transmural inflammation, skip lesions, and granulomas, which can affect any part of the GI tract.
- While it can present with abdominal pain, diarrhea, weight loss, and arthralgia, the presence of **PAS-positive macrophages** in the duodenum and neurological involvement are not typical features of Crohn's disease.
Question 388: A 38-year-old man comes to the emergency department because of epigastric pain and multiple episodes of vomiting for 4 hours. Initially, the vomit was yellowish in color, but after the first couple of episodes it was streaked with blood. He had 2 episodes of vomiting that contained streaks of frank blood on the way to the hospital. He has been hospitalized twice in the past year for acute pancreatitis. He drinks 2 pints of vodka daily but had over 4 pints during the past 12 hours. He takes naproxen for his 'hangovers.' He appears uncomfortable. His temperature is 37°C (99.1°F), pulse is 105/min, and blood pressure is 110/68 mm Hg. Examination shows dry mucous membranes and a tremor of his hands. The abdomen is soft and shows tenderness to palpation in the epigastric region; there is no organomegaly. Cardiopulmonary examination shows no abnormalities. Rectal examination is unremarkable. His hemoglobin concentration is 11.3 g/dL and hematocrit concentration is 40%. Which of the following is the most likely cause of this patient's findings?
A. Inflammation of the esophageal wall
B. Transmural tear of the lower esophagus
C. Pseudoaneurysm of the gastroduodenal artery
D. Neoplastic growth at the gastroesophageal junction
E. Mucosal tear at the gastroesophageal junction (Correct Answer)
Explanation: ***Mucosal tear at the gastroesophageal junction***
- The patient's history of heavy alcohol consumption, recurrent acute pancreatitis, and severe, repeated vomiting followed by **hematemesis** (Mallory-Weiss tear) strongly points to a mucosal tear.
- The use of naproxen, an **NSAID**, further increases the risk of gastric mucosal irritation and bleeding, compounding the effects of vomiting.
*Inflammation of the esophageal wall*
- While prolonged vomiting can cause esophagitis, **inflammation of the esophageal wall** typically presents with dysphagia and odynophagia, not rapidly progressing hematemesis associated with forceful vomiting.
- Esophagitis may cause superficial bleeding, but the described **streaks of frank blood** after initial yellowish vomit suggests a more significant mucosal breach.
*Transmural tear of the lower esophagus*
- A **transmural tear** (Boerhaave syndrome) is a medical emergency that would present with severe chest pain, subcutaneous emphysema, and signs of mediastinitis, which are not described in this patient.
- The patient's presentation of forceful vomiting leading to hematemesis is more consistent with a **Mallory-Weiss tear**, which is a mucosal tear and not transmural.
*Pseudoaneurysm of the gastroduodenal artery*
- A **pseudoaneurysm of the gastroduodenal artery** is a rare but life-threatening complication often associated with severe pancreatitis or abdominal trauma, leading to massive gastrointestinal bleeding.
- While the patient has a history of pancreatitis, the presence of **repeated forceful vomiting immediately preceding the hematemesis** makes a Mallory-Weiss tear more likely than a pseudoaneurysm as the primary cause in this acute presentation.
*Neoplastic growth at the gastroesophageal junction*
- **Neoplastic growth** typically presents with chronic symptoms such as progressive dysphagia, weight loss, and chronic, low-grade bleeding (melena or guaiac-positive stool) rather than acute, forceful vomiting leading to immediate hematemesis.
- The acute onset of symptoms following a binge of alcohol and repeated vomiting points away from a chronic cause like cancer and towards an **acute mechanical injury**.
Question 389: A 13-year-old boy presents to the emergency department with severe abdominal pain. His parents state that he has been complaining of abdominal pain that became increasingly severe this evening. They also state he has been eating much more lately yet still has been losing weight. The patient's past medical history is unremarkable and he is not currently on any medications. His temperature is 99.5°F (37.5°C), blood pressure is 90/58 mmHg, pulse is 150/min, respirations are 24/min, and oxygen saturation is 98% on room air. Physical exam is notable for diffuse abdominal tenderness and tachycardia. Laboratory values are ordered as seen below.
Hemoglobin: 12 g/dL
Hematocrit: 36%
Leukocyte count: 6,500/mm^3 with normal differential
Platelet count: 197,000/mm^3
Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.3 mEq/L
BUN: 20 mg/dL
Glucose: 599 mg/dL
Creatinine: 1.1 mg/dL
AST: 12 U/L
ALT: 10 U/L
Which of the following laboratory changes best reflects this patient's physiology as compared to his baseline?
A. Normal electrolyte levels
B. Slightly elevated creatinine
C. Significantly elevated blood glucose (Correct Answer)
D. Slightly decreased hematocrit
E. Normal white blood cell count
Explanation: **Significantly elevated blood glucose**
- The patient's **blood glucose** of 599 mg/dL is profoundly elevated, indicating a state of **hyperglycemia**, a hallmark of uncontrolled diabetes and a direct cause of his presenting symptoms.
- This extreme rise in blood glucose from a presumed normal baseline is the most significant physiological deviation and points towards **diabetic ketoacidosis (DKA)** given his acute presentation.
*Normal electrolyte levels*
- While the listed **Na+**, **K+**, and **Cl-** are within normal ranges, they can be misleading in DKA due to shifts in fluid and electrolyte balance; for instance, **pseudo-hyponatremia** can occur with severe hyperglycemia.
- The patient's underlying condition (likely DKA) significantly impacts fluid and electrolyte homeostasis, making "normal" readings potentially abnormal relative to his dehydrated state or prior to insulin therapy.
*Slightly elevated creatinine*
- A **creatinine** of 1.1 mg/dL is only marginally elevated and likely reflects **prerenal azotemia** due to dehydration, which is common in DKA.
- While reflecting a physiological change, it is a secondary finding related to fluid status rather than the primary metabolic derangement.
*Slightly decreased hematocrit*
- A **hematocrit** of 36% is within the normal range for a 13-year-old boy (typically 36-46%), so it is not considered a significant deviation.
- Even if slightly lower, it does not represent a critical physiological change in the context of his acute hyperglycemia and likely dehydration.
*Normal white blood cell count*
- A **white blood cell count** of 6,500/mm^3 with a normal differential is within the normal range and does not indicate an acute inflammatory or infectious process.
- In DKA, a normal WBC count does not typically rule out the condition, but an elevated count might suggest an underlying infection triggering DKA; its normalcy here means it doesn't reflect a major deviation.
Question 390: A 67-year-old African American woman visits the clinic with a complaint of progressive fatigue. These symptoms started gradually and slowly became worse over the past 4 months. She is short of breath after walking a few blocks and has difficulty climbing stairs. She denies having chest pain, leg swelling, or a cough. Her past medical history is significant for osteoporosis and gastroesophageal reflux disease. She takes omeprazole as needed and daily baby aspirin. She is a retired accountant and is a lifetime nonsmoker but she drinks a small glass of red wine every night before bed. Her diet is varied. Today, her blood pressure is 128/72 mm Hg, heart rate is 105/min, respiratory rate is 22/min, temperature 37.0°C (98.6°F) and oxygen saturation is 94% on room air. On physical examination, she has marked conjunctival pallor. Cardiac auscultation reveals a rapid heartbeat with a regular rhythm and a 2/6 systolic murmur over the right upper sternal border. Lungs are clear to auscultation bilaterally and abdominal examination was within normal limits. Peripheral blood smear shows microcytic, hypochromic red blood cells. The following laboratory values are obtained:
Hematocrit 29%
Hemoglobin 9.8 mg/dL
Mean red blood cell volume 78 fL
Platelets 240,000/mm3
Which of the following will most likely be present in this patient?
A. Thrombocytopenia
B. An increase in her reticulocyte count
C. A decrease in erythropoietin levels
D. Increased white blood cell count
E. A decrease in her reticulocyte count (Correct Answer)
Explanation: ***A decrease in her reticulocyte count***
- The patient's **microcytic, hypochromic anemia** combined with fatigue and shortness of breath suggests **iron deficiency anemia**. In iron deficiency, the bone marrow cannot produce enough healthy red blood cells, leading to a **decreased reticulocyte count** as there aren't enough precursors.
- Her history of osteoporosis and GERD, along with daily aspirin use and omeprazole, raises suspicion for **gastrointestinal blood loss** (even if occult), which is a common cause of iron deficiency in older adults.
*Thrombocytopenia*
- This patient's **platelet count is 240,000/mm3**, which is within the normal range. Thrombocytopenia is defined as a platelet count below 150,000/mm3.
- While some rare anemias can be associated with thrombocytopenia, it is not a typical finding in the common forms of iron deficiency anemia suggested by the patient's presentation.
*An increase in her reticulocyte count*
- An **increased reticulocyte count** would be expected in anemias where the bone marrow is actively compensating for red blood cell loss or destruction, such as **hemolytic anemia** or in response to effective treatment for iron deficiency.
- In untreated **iron deficiency anemia**, the bone marrow lacks the necessary building blocks (iron) to produce new red blood cells, thus the reticulocyte count is typically low or inappropriately normal.
*A decrease in erythropoietin levels*
- **Erythropoietin (EPO) levels** are typically **elevated** in anemia, especially in hypoproliferative anemias like iron deficiency, as the kidneys sense reduced oxygen delivery and try to stimulate red blood cell production.
- Decreased erythropoietin levels are more commonly associated with **anemia of chronic kidney disease** or primary bone marrow suppression.
*Increased white blood cell count*
- The patient's presentation with **iron deficiency anemia** does not suggest an infectious or inflammatory process that would typically lead to an **increased white blood cell count (leukocytosis)**.
- An elevated white blood cell count would indicate a concurrent infection, inflammation, or hematologic malignancy, none of which are suggested by the provided information.
