A 34-year-old female with a past medical history of a gastric sleeve operation for morbid obesity presents for pre-surgical clearance prior to a knee arthroplasty. Work-up reveals a hemoglobin of 8.7 g/dL, hematocrit of 26.1%, and MCV of 106 fL. With concern for folate deficiency, she is started on high dose folate supplementation, and her follow-up labs are as follows: hemoglobin of 10.1 g/dL, hematocrit of 28.5%, and MCV of 96 fL. Given her history of gastric sleeve surgery and associated malabsorption risks, she is at long-term risk for which complication?
Q252
A 44-year-old man comes to the physician because of progressive memory loss for the past 6 months. He reports that he often misplaces his possessions and has begun writing notes to remind himself of names and important appointments. He generally feels fatigued and unmotivated, and has poor concentration at work. He has also given up playing soccer because he feels slow and unsteady on his feet. He has also had difficulty swallowing food over the last two weeks. His temperature is 37.8°C (100°F), pulse is 82/min, respirations are 16/min, and blood pressure is 144/88 mm Hg. Examination shows confluent white plaques on the posterior oropharynx. Neurologic examination shows mild ataxia and an inability to perform repetitive rotary forearm movements. Mental status examination shows a depressed mood and short-term memory deficits. Serum glucose, vitamin B12 (cyanocobalamin), and thyroid-stimulating hormone concentrations are within the reference range. Upper esophagogastroduodenoscopy shows streaky, white-grayish lesions. Which of the following is the most likely underlying cause of this patient's neurological symptoms?
Q253
A 57-year-old man presents with 2 days of severe, generalized, abdominal pain that is worse after meals. He is also nauseated and reports occasional diarrhea mixed with blood. Apart from essential hypertension, his medical history is unremarkable. His vital signs include a temperature of 36.9°C (98.4°F), blood pressure of 145/92 mm Hg, and an irregularly irregular pulse of 105/min. Physical examination is only notable for mild periumbilical tenderness. Which of the following is the most likely diagnosis?
Q254
A 46-year-old man presents with increasing fatigue and weakness for the past 3 months. He works as a lawyer and is handling a complicated criminal case which is very stressful, and he attributes his fatigue to his work. He lost 2.3 kg (5.0 lb) during this time despite no change in diet or activity level. His past history is significant for chronic constipation and infrequent episodes of bloody stools. Family history is significant for his father and paternal uncle who died of colon cancer and who were both known to possess a genetic mutation for the disease. He has never had a colonoscopy or had any genetic testing performed. Physical examination is significant for conjunctival pallor. A colonoscopy is performed and reveals few adenomatous polyps. Histopathologic examination shows high-grade dysplasia and genetic testing reveals the same mutation as his father and uncle. The patient is concerned about his 20-year-old son. Which of the following is the most appropriate advice regarding this patient's son?
Q255
A 27-year-old male presents to clinic complaining of coughing up small amounts of blood daily for the past week. He denies smoking, sick contacts, or recent travel. Chest radiographs demonstrates interstitial pneumonia with patchy alveolar infiltrates suggestive of multiple bleeding sites. Urinalysis is positive for blood and protein. A positive result is returned for anti-glomerular basement membrane antibody (anti-GBM Ab). What is the most likely diagnosis?
Q256
A 68-year-old woman presents to her primary care physician with a complaint of fatigue, difficulty breathing upon exertion, and crampy lower abdominal pain. She also noticed that her stools appear darker than usual. She has had essential hypertension for 20 years, for which she takes bisoprolol. Her family history is positive for type 2 diabetes mellitus. On physical examination, she looks pale. Complete blood count shows the following:
Hemoglobin 10 g/dL
Mean corpuscular volume (MCV) 70 fL
Mean corpuscular hemoglobin (MCH) 25 pg/cell
Mean corpuscular hemoglobin concentration (MCHC) 27 g/dL
Red cell distribution width 16%
Platelet count 350,000/mm3
Serum ferritin 9 ng/mL
Which of the following is the best initial step for this patient?
Q257
A 65-year-old man presents to the emergency department with a fever and weakness. He states his symptoms started yesterday and have been gradually worsening. The patient has a past medical history of obesity, diabetes, alcohol abuse, as well as a 30 pack-year smoking history. He lives in a nursing home and has presented multiple times in the past for ulcers and delirium. His temperature is 103°F (39.4°C), blood pressure is 122/88 mmHg, pulse is 129/min, respirations are 24/min, and oxygen saturation is 99% on room air. Physical exam is notable for a murmur. The patient is started on vancomycin and piperacillin-tazobactam and is admitted to the medicine floor. During his hospital stay, blood cultures grow Streptococcus bovis and his antibiotics are appropriately altered. A transesophageal echocardiograph is within normal limits. The patient’s fever decreases and his symptoms improve. Which of the following is also necessary in this patient?
Q258
A 47-year-old male presents to his primary care physician complaining of upper abdominal pain. He reports a four-month history of gnawing epigastric discomfort that improves with meals. He has lost 10 pounds over that same period. His past medical history is significant for a prolactinoma for which he underwent transphenoidal resection. He does not smoke or drink alcohol. His family history is notable for a paternal uncle and paternal grandmother with parathyroid neoplasms. His temperature is 99°F (37.2°C), blood pressure is 115/80 mmHg, pulse is 80/min, and respirations are 18/min. Upon further diagnostic workup, which of the following sets of laboratory findings is most likely?
Q259
A 40-year-old Caucasian woman presents to the physician with urinary frequency, urgency, and pelvic pain for 1 week. She has poor sleep quality because her symptoms persist throughout the night, as well as the day. Her pain partially subsides with urination. She does not have dysuria or urinary incontinence. Her menstrual cycles are regular. Over the past 6 months, she has had several similar episodes, each lasting 1–2 weeks. She has been relatively symptom-free between episodes. Her symptoms began 6 months ago after an established diagnosis of cystitis, for which she was treated with appropriate antibiotics. Since that time, urine cultures have consistently been negative. Her past history is significant for a diagnosis of fibromyalgia 2 years ago, multiple uterine fibroids, irritable bowel syndrome, and depression. She takes tramadol occasionally and sertraline daily. The vital signs are within normal limits. The neurologic examination showed no abnormalities. Examination of the abdomen, pelvis, and rectum was unremarkable. Cystoscopy reinspection after full distension and drainage reveals small, petechial hemorrhages throughout the bladder except for the trigone. Which of the following is the most appropriate next step in management?
Q260
A 20-year-old woman comes to the physician for the evaluation of fatigue and low energy levels for 2 months. She has not had fever or weight changes. She has no history of serious illness except for an episode of infectious mononucleosis 4 weeks ago. Menses occur at regular 28-day intervals and last 5 days with moderate flow. Her last menstrual period was 3 weeks ago. Her mother has Hashimoto's thyroiditis. Vital signs are within normal limits. Examination shows pale conjunctivae, inflammation of the corners of the mouth, and brittle nails. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 10.3 g/dL
Mean corpuscular volume 74 μm3
Platelet count 280,000/mm3
Leukocyte count 6,000/mm3
Which of the following is the most appropriate initial step in management?
Gastroenterology US Medical PG Practice Questions and MCQs
Question 251: A 34-year-old female with a past medical history of a gastric sleeve operation for morbid obesity presents for pre-surgical clearance prior to a knee arthroplasty. Work-up reveals a hemoglobin of 8.7 g/dL, hematocrit of 26.1%, and MCV of 106 fL. With concern for folate deficiency, she is started on high dose folate supplementation, and her follow-up labs are as follows: hemoglobin of 10.1 g/dL, hematocrit of 28.5%, and MCV of 96 fL. Given her history of gastric sleeve surgery and associated malabsorption risks, she is at long-term risk for which complication?
A. Peripheral neuropathy (Correct Answer)
B. Macular degeneration
C. Hypothyroidism
D. Microcytic anemia
E. Neural tube defects
Explanation: ***Peripheral neuropathy***
- Gastric sleeve surgery can lead to **vitamin B12 deficiency** due to the removal of the fundus, which produces **intrinsic factor** necessary for B12 absorption.
- **Vitamin B12 deficiency** is a known cause of **peripheral neuropathy**, manifesting as numbness, tingling, and weakness.
*Macular degeneration*
- This condition is primarily associated with **aging**, **genetics**, and **environmental factors** like smoking, rather than micronutrient deficiencies post-gastric sleeve.
- While certain vitamins (e.g., A, C, E) and minerals can influence macular health, there's no direct strong causal link between bariatric surgery malabsorption and increased risk of **macular degeneration**.
*Hypothyroidism*
- Hypothyroidism is most commonly caused by **autoimmune conditions** like Hashimoto's thyroiditis or **iodine deficiency**.
- While bariatric surgery can influence overall metabolic health, it does not directly lead to an increased risk of primary hypothyroidism.
*Microcytic anemia*
- **Microcytic anemia** is characterized by **small red blood cells (low MCV)**, typically caused by **iron deficiency** or **thalassemia**.
- The patient initially presented with **macrocytic anemia (MCV 106 fL)**, which improved with folate, but the underlying risk remains for macrocytic rather than microcytic anemia from malabsorption of B12 or folate.
*Neural tube defects*
- **Neural tube defects** are congenital anomalies that occur during early fetal development, primarily linked to **folate deficiency during pregnancy**.
- While the patient had a folate deficiency, this complication is relevant to **fetal development** and not a long-term risk for the adult patient herself after surgery.
Question 252: A 44-year-old man comes to the physician because of progressive memory loss for the past 6 months. He reports that he often misplaces his possessions and has begun writing notes to remind himself of names and important appointments. He generally feels fatigued and unmotivated, and has poor concentration at work. He has also given up playing soccer because he feels slow and unsteady on his feet. He has also had difficulty swallowing food over the last two weeks. His temperature is 37.8°C (100°F), pulse is 82/min, respirations are 16/min, and blood pressure is 144/88 mm Hg. Examination shows confluent white plaques on the posterior oropharynx. Neurologic examination shows mild ataxia and an inability to perform repetitive rotary forearm movements. Mental status examination shows a depressed mood and short-term memory deficits. Serum glucose, vitamin B12 (cyanocobalamin), and thyroid-stimulating hormone concentrations are within the reference range. Upper esophagogastroduodenoscopy shows streaky, white-grayish lesions. Which of the following is the most likely underlying cause of this patient's neurological symptoms?
A. Pseudodementia
B. HIV-related encephalopathy (Correct Answer)
C. Frontotemporal dementia
D. Cerebral toxoplasmosis
E. Primary CNS lymphoma
Explanation: ***HIV-related encephalopathy***
- The patient's progressive **memory loss**, **ataxia**, **depressed mood**, and **oropharyngeal candidiasis** (white plaques) are highly suggestive of advanced HIV infection, which can lead to HIV-related encephalopathy.
- The neurological symptoms, combined with signs of opportunistic infection, point towards an immunocompromised state, fitting with HIV as the underlying cause.
*Pseudodementia*
- This condition is characterized by cognitive deficits that resemble dementia but are actually caused by an underlying **depressive disorder**, which improves with antidepressant treatment.
- While the patient has a depressed mood and memory deficits, the presence of **ataxia** and **oropharyngeal candidiasis** suggests an organic neurological cause rather than just depression.
*Frontotemporal dementia*
- This neurodegenerative disorder typically presents with prominent **behavioral changes** (e.g., disinhibition, apathy) or **language difficulties** (e.g., aphasia) early in the disease course.
- The patient's primary symptoms of memory loss, ataxia, and signs of fungal infection are not characteristic features of early frontotemporal dementia.
*Cerebral toxoplasmosis*
- This is an **opportunistic infection** typically seen in severely immunocompromised individuals, such as those with advanced HIV, and can cause neurological symptoms like focal deficits, seizures, and altered mental status.
- However, the gradual onset of diffuse cognitive decline, ataxia, and absence of focal neurological deficits, along with prominent candidiasis, makes HIV-related encephalopathy a more encompassing diagnosis than isolated cerebral toxoplasmosis.
*Primary CNS lymphoma*
- This is another **HIV-associated malignancy** that can present with neurological symptoms such as focal neurological deficits, seizures, and cognitive changes.
- While possible in an immunocompromised patient, the diffuse nature of the cognitive decline, the gait disturbances, and the presence of widespread candidiasis make the more direct effect of HIV on the brain (encephalopathy) more likely as the primary driver of these specific symptoms.
Question 253: A 57-year-old man presents with 2 days of severe, generalized, abdominal pain that is worse after meals. He is also nauseated and reports occasional diarrhea mixed with blood. Apart from essential hypertension, his medical history is unremarkable. His vital signs include a temperature of 36.9°C (98.4°F), blood pressure of 145/92 mm Hg, and an irregularly irregular pulse of 105/min. Physical examination is only notable for mild periumbilical tenderness. Which of the following is the most likely diagnosis?
A. Diverticular disease
B. Acute pancreatitis
C. Gastroenteritis
D. Crohn's disease
E. Acute mesenteric ischemia (Correct Answer)
Explanation: ***Acute mesenteric ischemia***
- The patient's presentation with **severe, generalized abdominal pain worse after meals**, along with **bloody diarrhea** and **irregularly irregular pulse** (suggesting **atrial fibrillation**), is highly indicative of acute mesenteric ischemia.
- Atrial fibrillation can lead to **emboli** that occlude mesenteric arteries, causing rapid onset of **ischemic bowel injury** with disproportionate pain and often minimal findings on physical exam.
*Diverticular disease*
- While diverticulitis can cause abdominal pain, it is typically localized to the **left lower quadrant** and often associated with fever and leukocytosis, which are absent here.
- **Diverticular bleeding** usually presents as painless rectal bleeding, not severe, diffuse abdominal pain with ischemic features.
*Acute pancreatitis*
- Characterized by severe **epigastric pain radiating to the back**, often associated with nausea and vomiting, but not typically with bloody diarrhea.
- Elevated **lipase** and **amylase** levels are diagnostic markers, and an irregularly irregular pulse is not a direct symptom.
*Gastroenteritis*
- Often causes diffuse abdominal pain, nausea, vomiting, and diarrhea, but the pain is rarely as severe or disproportionate to physical findings as described.
- **Bloody diarrhea** can occur, but the rapid onset of severe pain, particularly in the context of possible **embolic source** (atrial fibrillation), makes ischemia more likely.
*Crohn's disease*
- A chronic inflammatory bowel disease presenting with **abdominal pain**, **diarrhea** (often bloody), and weight loss, developing over weeks to months.
- The acute, severe onset of symptoms in this patient does not fit the typical chronic presentation of Crohn's disease.
Question 254: A 46-year-old man presents with increasing fatigue and weakness for the past 3 months. He works as a lawyer and is handling a complicated criminal case which is very stressful, and he attributes his fatigue to his work. He lost 2.3 kg (5.0 lb) during this time despite no change in diet or activity level. His past history is significant for chronic constipation and infrequent episodes of bloody stools. Family history is significant for his father and paternal uncle who died of colon cancer and who were both known to possess a genetic mutation for the disease. He has never had a colonoscopy or had any genetic testing performed. Physical examination is significant for conjunctival pallor. A colonoscopy is performed and reveals few adenomatous polyps. Histopathologic examination shows high-grade dysplasia and genetic testing reveals the same mutation as his father and uncle. The patient is concerned about his 20-year-old son. Which of the following is the most appropriate advice regarding this patient's son?
A. The son doesn't need to be tested now.
B. An immediate colonoscopy should be ordered for the son.
C. Screening can be started by 50 years of age as the son’s risk is similar to the general population.
D. The son should undergo a prophylactic colonic resection.
E. A genetic test followed by colonoscopy for the son should be ordered. (Correct Answer)
Explanation: ***A genetic test followed by colonoscopy for the son should be ordered.***
- Given the patient's strong family history of **colon cancer** with a known genetic mutation and the patient's own diagnosis of **high-grade dysplasia** and the same mutation, his son is at a significantly increased risk.
- **Genetic testing** will determine if the son has inherited the mutation, and if positive, early and regular **colonoscopic surveillance** is crucial due to the highly aggressive nature of familial colon cancer syndromes.
*The son doesn't need to be tested now.*
- This statement is incorrect because the son is at a very high risk of inheriting a **known pathogenic genetic mutation** that predisposes to colon cancer.
- Delaying testing could lead to a delayed diagnosis of potentially cancerous or pre-cancerous lesions, missing the opportunity for **early intervention**.
*An immediate colonoscopy should be ordered for the son.*
- While a colonoscopy may be warranted, the initial step should be **genetic testing** to confirm the presence of the mutation.
- If the genetic test is negative, the urgency and frequency of colonoscopies would be different, potentially aligning with general population guidelines or slightly earlier, but not necessarily immediately at age 20 without genetic confirmation.
*Screening can be started by 50 years of age as the son’s risk is similar to the general population.*
- This advice is dangerously incorrect, as the son's risk is *not* similar to the general population due to a strong and **documented family history** of colon cancer with a **known genetic mutation**.
- Waiting until 50 years of age would likely result in delayed detection of advanced adenomas or even cancer, as familial syndromes typically present at a much **younger age**.
*The son should undergo a prophylactic colonic resection.*
- **Prophylactic colonic resection** is a major surgical procedure and is typically reserved for individuals with established diagnoses of certain high-risk syndromes, such as **Familial Adenomatous Polyposis (FAP)**, often after they have developed numerous polyps.
- This decision should only be made after **genetic confirmation** of the mutation, thorough evaluation of polyp burden, and shared decision-making with the patient and multidisciplinary team, and not as an initial step.
Question 255: A 27-year-old male presents to clinic complaining of coughing up small amounts of blood daily for the past week. He denies smoking, sick contacts, or recent travel. Chest radiographs demonstrates interstitial pneumonia with patchy alveolar infiltrates suggestive of multiple bleeding sites. Urinalysis is positive for blood and protein. A positive result is returned for anti-glomerular basement membrane antibody (anti-GBM Ab). What is the most likely diagnosis?
A. Granulomatosis with polyangiitis (Wegener's)
B. Goodpasture disease (Correct Answer)
C. Microscopic polyangiitis
D. Churg-Strauss syndrome
E. Systemic lupus erythematosus (SLE)
Explanation: **Goodpasture disease**
- The presence of **hemoptysis** (coughing up blood), **interstitial pneumonia** with alveolar infiltrates, **hematuria**, **proteinuria**, and a positive **anti-glomerular basement membrane (anti-GBM) antibody** is classic for Goodpasture disease.
- This condition involves an **autoimmune attack** against type IV collagen in the basement membranes of the **kidneys** and **lungs**.
*Granulomatosis with polyangiitis (Wegener's)*
- While it can cause **pulmonary-renal syndrome**, it is typically associated with **anti-neutrophil cytoplasmic antibodies (ANCA)**, specifically c-ANCA, not anti-GBM antibodies.
- It often presents with involvement of the **upper respiratory tract** (e.g., sinusitis, otitis media), which is not mentioned in this case.
*Microscopic polyangiitis*
- This is another ANCA-associated vasculitis (p-ANCA predominant) that can cause **pulmonary-renal syndrome**.
- However, it does **not involve granuloma formation** and is not characterized by anti-GBM antibodies.
*Churg-Strauss syndrome*
- This condition, now known as **Eosinophilic Granulomatosis with Polyangiitis (EGPA)**, is characterized by **asthma**, **eosinophilia**, and **granulomatous inflammation**.
- It is also ANCA-associated (p-ANCA in about 50% of cases) and does not typically involve anti-GBM antibodies.
*Systemic lupus erythematosus (SLE)*
- SLE can cause **renal involvement** (lupus nephritis) and **pulmonary manifestations** (e.g., hemorrhage, pneumonitis).
- However, it is characterized by the presence of various autoantibodies like **anti-nuclear antibodies (ANA)**, anti-dsDNA, and anti-Sm, not anti-GBM antibodies.
Question 256: A 68-year-old woman presents to her primary care physician with a complaint of fatigue, difficulty breathing upon exertion, and crampy lower abdominal pain. She also noticed that her stools appear darker than usual. She has had essential hypertension for 20 years, for which she takes bisoprolol. Her family history is positive for type 2 diabetes mellitus. On physical examination, she looks pale. Complete blood count shows the following:
Hemoglobin 10 g/dL
Mean corpuscular volume (MCV) 70 fL
Mean corpuscular hemoglobin (MCH) 25 pg/cell
Mean corpuscular hemoglobin concentration (MCHC) 27 g/dL
Red cell distribution width 16%
Platelet count 350,000/mm3
Serum ferritin 9 ng/mL
Which of the following is the best initial step for this patient?
A. Colonoscopy (Correct Answer)
B. Red cell transfusion
C. Rectal hydrocortisone
D. Intra-anal glyceryl trinitrate
E. Double-contrast barium enema
Explanation: ***Colonoscopy***
- The patient's symptoms (fatigue, dyspnea on exertion, darker stools, crampy lower abdominal pain) and lab findings (**microcytic hypochromic anemia** with **low ferritin and elevated RDW**) are highly suggestive of **iron deficiency anemia** due to **gastrointestinal blood loss**.
- In adults over 50 years with new-onset iron deficiency anemia, the primary concern is **colorectal cancer**, making **colonoscopy** the priority initial diagnostic test.
- While iron deficiency anemia may require evaluation of both upper and lower GI tracts, in this age group (68 years) with lower abdominal symptoms, **colonoscopy should be performed first** to rule out malignancy.
- The combination of her age, anemia, and GI symptoms warrants immediate investigation for **colon cancer** or other significant lower GI pathology.
*Red cell transfusion*
- While this provides immediate **symptomatic relief** for severe anemia, it is a supportive measure and does not address the underlying cause of the bleeding.
- Her hemoglobin of 10 g/dL is not acutely life-threatening and allows time for diagnostic workup before considering transfusion.
*Rectal hydrocortisone*
- This is used to treat **inflammatory bowel disease** or proctitis, neither of which is indicated by the presented symptoms or lab findings.
- It would not help determine the source of gastrointestinal bleeding or treat iron deficiency anemia.
*Intra-anal glyceryl trinitrate*
- This medication is primarily used to treat **anal fissures** by promoting muscle relaxation and blood flow, which is not indicated in this case.
- The patient's symptoms suggest a more significant source of blood loss than an anal fissure, which typically presents with bright red blood per rectum and severe pain on defecation.
*Double-contrast barium enema*
- This imaging technique has largely been replaced by **colonoscopy** for evaluating the colon due to its lower sensitivity for detecting small lesions and inability to obtain biopsies.
- It is not considered the best initial step for investigating GI bleeding or iron deficiency anemia in the lower tract.
Question 257: A 65-year-old man presents to the emergency department with a fever and weakness. He states his symptoms started yesterday and have been gradually worsening. The patient has a past medical history of obesity, diabetes, alcohol abuse, as well as a 30 pack-year smoking history. He lives in a nursing home and has presented multiple times in the past for ulcers and delirium. His temperature is 103°F (39.4°C), blood pressure is 122/88 mmHg, pulse is 129/min, respirations are 24/min, and oxygen saturation is 99% on room air. Physical exam is notable for a murmur. The patient is started on vancomycin and piperacillin-tazobactam and is admitted to the medicine floor. During his hospital stay, blood cultures grow Streptococcus bovis and his antibiotics are appropriately altered. A transesophageal echocardiograph is within normal limits. The patient’s fever decreases and his symptoms improve. Which of the following is also necessary in this patient?
A. Addiction medicine referral
B. Colonoscopy (Correct Answer)
C. Social work consult for elder abuse
D. Repeat blood cultures for contamination concern
E. Replace the patient’s central line and repeat echocardiography
Explanation: ***Colonoscopy***
- The isolation of **_Streptococcus bovis_** (now often referred to as _Streptococcus gallolyticus_) from blood cultures is highly associated with **colorectal neoplasms** or other gastrointestinal pathologies.
- A comprehensive workup, including a **colonoscopy**, is crucial to identify the underlying source of bacteremia and screen for malignancy.
*Addiction medicine referral*
- While the patient has a history of **alcohol abuse**, there is no indication that his current presentation or the discovery of _Streptococcus bovis_ necessitates an immediate addiction medicine referral as the primary next step from an acute management perspective.
- Addiction management is an important long-term consideration but not the most pressing diagnostic need.
*Social work consult for elder abuse*
- The patient lives in a **nursing home** and has a history of delirium and frequent hospitalizations for ulcers, which can be concerning. However, there are no specific signs or symptoms presented in this vignette that directly suggest elder abuse as the reason for his current _S. bovis_ bacteremia, making it a less immediate priority compared to diagnosing the source of infection.
- While a general social work assessment might be beneficial for a vulnerable patient in a nursing home, it is not the most necessary intervention based on the microbiological finding.
*Repeat blood cultures for contamination concern*
- The question states that **_Streptococcus bovis_** blood cultures "grew" and antibiotics were "appropriately altered," suggesting a confirmed infection rather than contamination.
- Furthermore, _S. bovis_ is a known pathogen with specific associations and is not typically considered a common contaminant in the same vein as coagulase-negative staphylococci.
*Replace the patient’s central line and repeat echocardiography*
- The patient's **transesophageal echocardiogram (TEE) was normal**, ruling out endocarditis as the source of bacteremia in this case.
- There is no mention of a central line, and even if there were, the normal TEE and the specific pathogen (_S. bovis_) point towards a gastrointestinal source.
Question 258: A 47-year-old male presents to his primary care physician complaining of upper abdominal pain. He reports a four-month history of gnawing epigastric discomfort that improves with meals. He has lost 10 pounds over that same period. His past medical history is significant for a prolactinoma for which he underwent transphenoidal resection. He does not smoke or drink alcohol. His family history is notable for a paternal uncle and paternal grandmother with parathyroid neoplasms. His temperature is 99°F (37.2°C), blood pressure is 115/80 mmHg, pulse is 80/min, and respirations are 18/min. Upon further diagnostic workup, which of the following sets of laboratory findings is most likely?
A. Elevated fasting serum gastrin that increases with secretin administration (Correct Answer)
B. Elevated fasting serum gastrin that decreases with secretin administration
C. Elevated fasting serum gastrin that decreases with cholecystokinin administration
D. Elevated fasting serum gastrin that increases with somatostatin administration
E. Normal fasting serum gastrin
Explanation: ***Elevated fasting serum gastrin that increases with secretin administration***
- The patient's presentation with **gnawing epigastric discomfort improving with meals**, weight loss, and a history of **prolactinoma** (suggesting MEN1) points strongly to **Zollinger-Ellison syndrome (ZES)**, caused by a gastrinoma.
- In ZES, gastrinomas uniquely have **ectopic secretin receptors**, leading to a paradoxical increase in gastrin levels after secretin administration, which is a diagnostic hallmark.
*Elevated fasting serum gastrin that decreases with secretin administration*
- This response is typical for **non-gastrinoma hypergastrinemia**, such as that seen in **atrophic gastritis** with low gastric acid production.
- Secretin normally inhibits gastrin release by parietal cells, but gastrinomas are autonomous and respond paradoxically.
*Elevated fasting serum gastrin that decreases with cholecystokinin administration*
- **Cholecystokinin (CCK)** primarily stimulates pancreatic enzyme and gallbladder contraction, and its administration is not a standard diagnostic test for gastrinoma or ZES gastrin response.
- Gastrinomas are typically **unresponsive to CCK** in a predictable manner that would aid in diagnosis.
*Elevated fasting serum gastrin that increases with somatostatin administration*
- **Somatostatin** is a potent inhibitor of gastrin release from both normal G cells and gastrinomas.
- An **increase in gastrin with somatostatin** administration would be highly unusual and not characteristic of any known gastrinopathy.
*Normal fasting serum gastrin*
- Given the patient's symptoms (severe, chronic ulcer-like pain, weight loss) and his family history and personal history of prolactinoma suggestive of **MEN1**, a **normal fasting gastrin level** would make Zollinger-Ellison syndrome much less likely.
- **Hypergastrinemia** is a prerequisite for diagnosing ZES and would be expected in this clinical context.
Question 259: A 40-year-old Caucasian woman presents to the physician with urinary frequency, urgency, and pelvic pain for 1 week. She has poor sleep quality because her symptoms persist throughout the night, as well as the day. Her pain partially subsides with urination. She does not have dysuria or urinary incontinence. Her menstrual cycles are regular. Over the past 6 months, she has had several similar episodes, each lasting 1–2 weeks. She has been relatively symptom-free between episodes. Her symptoms began 6 months ago after an established diagnosis of cystitis, for which she was treated with appropriate antibiotics. Since that time, urine cultures have consistently been negative. Her past history is significant for a diagnosis of fibromyalgia 2 years ago, multiple uterine fibroids, irritable bowel syndrome, and depression. She takes tramadol occasionally and sertraline daily. The vital signs are within normal limits. The neurologic examination showed no abnormalities. Examination of the abdomen, pelvis, and rectum was unremarkable. Cystoscopy reinspection after full distension and drainage reveals small, petechial hemorrhages throughout the bladder except for the trigone. Which of the following is the most appropriate next step in management?
A. Bladder hydrodistention
B. Behavior modification (Correct Answer)
C. Intravesical dimethyl sulfoxide
D. Oxybutynin
E. Amitriptyline
Explanation: ***Behavior modification***
- **Behavior modification** including **dietary changes** and **stress reduction** is the initial and most appropriate step in managing interstitial cystitis/bladder pain syndrome (IC/BPS).
- This patient's symptoms (urinary frequency, urgency, pelvic pain, negative urine cultures, pain relief with urination, prior fibromyalgia, IBS, depression) are highly suggestive of IC/BPS, for which conservative measures are first-line.
*Bladder hydrodistention*
- While bladder hydrodistention is a diagnostic and therapeutic procedure for IC/BPS, it is typically considered after **conservative treatments** have failed.
- It involves stretching the bladder wall and can temporarily relieve symptoms, but is not the initial management step.
*Intravesical dimethyl sulfoxide*
- **Intravesical dimethyl sulfoxide (DMSO)** is a second- or third-line treatment for IC/BPS, used when initial conservative and oral therapies are insufficient.
- It works by reducing inflammation and pain in the bladder, but is not prescribed as a first-line therapy due to its invasive nature and potential side effects.
*Oxybutynin*
- **Oxybutynin** is an **antimuscarinic medication** primarily used to treat **overactive bladder** symptoms like urgency and frequency, but it is not recommended for IC/BPS.
- In IC/BPS, the urgency and frequency are due to bladder wall inflammation and pain, not necessarily detrusor overactivity, and antimuscarinics can sometimes worsen symptoms by causing **urinary retention**.
*Amitriptyline*
- **Amitriptyline** is a **tricyclic antidepressant** often used in IC/BPS due to its **analgesic** and **antihistamine** properties, and it can improve sleep.
- However, it is typically considered a **second-line oral therapy** after conservative behavioral modifications have been attempted and proven insufficient.
Question 260: A 20-year-old woman comes to the physician for the evaluation of fatigue and low energy levels for 2 months. She has not had fever or weight changes. She has no history of serious illness except for an episode of infectious mononucleosis 4 weeks ago. Menses occur at regular 28-day intervals and last 5 days with moderate flow. Her last menstrual period was 3 weeks ago. Her mother has Hashimoto's thyroiditis. Vital signs are within normal limits. Examination shows pale conjunctivae, inflammation of the corners of the mouth, and brittle nails. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 10.3 g/dL
Mean corpuscular volume 74 μm3
Platelet count 280,000/mm3
Leukocyte count 6,000/mm3
Which of the following is the most appropriate initial step in management?
A. Iron studies (Correct Answer)
B. Vitamin B12 levels
C. Peripheral blood smear
D. Hemoglobin electrophoresis
E. Direct Coombs test
Explanation: ***Iron studies***
- The patient presents with **microcytic anemia** (Hb 10.3 g/dL, MCV 74 μm3), along with symptoms like **fatigue**, pale conjunctivae, angular cheilitis, and brittle nails, all highly suggestive of **iron deficiency anemia**.
- **Iron studies** (serum iron, ferritin, total iron-binding capacity, transferrin saturation) are crucial to confirm the diagnosis and determine the severity of iron deficiency.
*Vitamin B12 levels*
- **Vitamin B12 deficiency** typically causes **macrocytic anemia** (elevated MCV), which is not consistent with the patient's **low MCV (74 μm3)**.
- While fatigue is a symptom, the other clinical signs and lab results point away from B12 deficiency.
*Peripheral blood smear*
- A **peripheral blood smear** may show microcytic, hypochromic red blood cells if iron deficiency is present, but it does not quantify **iron stores** or establish the cause definitively.
- While useful for morphological assessment, it is usually performed after initial labs suggest a specific type of anemia, and **iron studies** are more direct for diagnosing iron deficiency.
*Hemoglobin electrophoresis*
- **Hemoglobin electrophoresis** is used to diagnose hemoglobinopathies like **thalassemia** or **sickle cell disease**.
- While some thalassemias can cause microcytic anemia, the clinical picture with **angular cheilitis** and **brittle nails** strongly points towards iron deficiency, making iron studies a more appropriate initial step.
*Direct Coombs test*
- The **Direct Coombs test** is used to diagnose **autoimmune hemolytic anemia**, where antibodies are bound to the surface of red blood cells leading to their destruction.
- This patient's presentation does not suggest hemolysis (e.g., jaundice, splenomegaly, elevated LDH, low haptoglobin), and the dominant feature is **microcytic anemia from likely iron deficiency**.
