A 74-year-old man presents to the physician with a painful lesion over his right lower limb which began 2 days ago. He says that the lesion began with pain and severe tenderness in the area. The next day, the size of the lesion increased and it became erythematous. He also mentions that a similar lesion had appeared over his left lower limb 3 weeks earlier, but it disappeared after a few days of taking over the counter analgesics. There is no history of trauma, and the man does not have any known medical conditions. On physical examination, the physician notes a cordlike tender area with erythema and edema. There are no signs suggestive of deep vein thrombosis or varicose veins. Which of the following malignancies is most commonly associated with the lesion described in the patient?
Q412
A 23-year-old woman presents with fever, chills, nausea, and urinary urgency and frequency. She says that her symptoms began 4 days ago and have progressively worsened. Her past medical history is significant for a 6-month history of recurrent urinary tract infections (UTIs). Her vital signs include: temperature 39.0°C (102.2°F), blood pressure 100/70 mm Hg, pulse 92/min, and respiratory rate 25/min. On physical examination, there is moderate left costovertebral angle tenderness. Laboratory findings are significant for the following:
WBC 8,500/mm3
RBC 4.20 x 106/mm3
Hematocrit 41.5%
Hemoglobin 13.0 g/dL
Platelet count 225,000/mm3
Urinalysis
Color Dark yellow
Clarity Turbid
pH 6.5
Specific gravity 1.026
Glucose None
Ketones None
Nitrites Positive
Leukocyte esterase Positive
Bilirubin Negative
Urobilirubin 0.6 mg/dL
Protein Trace
Blood None
WBC 25/hpf
Bacteria Many
Which of the following is the most likely diagnosis in this patient?
Q413
A 42-year-old woman is brought to the emergency department because of intermittent sharp right upper quadrant abdominal pain and nausea for the past 10 hours. She has vomited 3 times. There is no associated fever, chills, diarrhea, or urinary symptoms. She has 2 children who both attend high school. She appears uncomfortable. She is 165 cm (5 ft 5 in) tall and weighs 86 kg (190 lb). Her BMI is 32 kg/m2. Her temperature is 37.0°C (98.6°F), pulse is 100/min, and blood pressure is 140/90 mm Hg. She has mild scleral icterus. On physical examination, her abdomen is soft and nondistended, with tenderness to palpation of the right upper quadrant without guarding or rebound. Bowel sounds are normal. Laboratory studies show the following:
Blood
Hemoglobin count 14 g/dL
Leukocyte count 9,000 mm3
Platelet count 160,000 mm3
Serum
Alkaline phosphatase 238 U/L
Aspartate aminotransferase 60 U/L
Bilirubin
Total 2.8 mg/dL
Direct 2.1 mg/dL
Which of the following is the most appropriate next step in diagnosis?
Q414
A 23-year-old woman comes to the emergency department for increasing abdominal pain and confusion for 3 days. The pain is constant and she describes it as 8 out of 10 in intensity. She has the strong feeling that she is being watched. She has not had a bowel movement for 2 days. She began experiencing tingling in parts of her lower extremities 4 hours ago. She consumed a large number of alcoholic beverages prior to the onset of the abdominal pain. Her temperature is 38°C (100.8°F), pulse is 113/min, and blood pressure is 148/88 mm Hg. She appears distracted and admits to hearing whispering intermittently during the examination, which shows a distended abdomen and mild tenderness to palpation diffusely. There is no guarding or rebound tenderness present. Bowel sounds are decreased. There is weakness of the iliopsoas and hamstring muscles. Sensation is decreased over the lower extremities. Deep tendon reflexes are 2+ in the lower extremities. Mental status examination shows she is oriented only to person and place. A complete blood count and serum concentrations of electrolytes, glucose, creatinine are within the reference range. Which of the following is the most appropriate next step in management?
Q415
A 40-year-old woman, gravida 2, para 2, comes to the physician because of fatigue, nausea, joint pain, and mild flank pain for 2 months. She has refractory acid reflux and antral and duodenal peptic ulcers for which she takes omeprazole. She also has chronic, foul-smelling, light-colored diarrhea. Five years ago she was successfully treated for infertility with bromocriptine. She reports recently feeling sad and unmotivated at work. She does not smoke or drink alcohol. She is 175 cm (5 ft 9 in) tall and weighs 100 kg (220 lb); BMI is 32.7 kg/m2. Her temperature is 37°C (98.8°F), pulse is 78/min, and blood pressure is 150/90 mm Hg. Cardiopulmonary examination shows no abnormalities. The abdomen is moderately distended and diffusely tender to palpation. There is mild costovertebral angle tenderness. Her serum calcium concentration is 12 mg/dL, phosphorus concentration is 2 mg/dL, and parathyroid hormone level is 900 pg/mL. Abdominal ultrasound shows mobile echogenic foci with acoustic shadowing in her ureteropelvic junctions bilaterally. A mutation in which of the following genes is most likely present in this patient?
Q416
A 27-year-old man presents to his primary care physician with worsening cough and asthma. The patient reports that he was in his usual state of health until 1 month ago, when he developed a cold. Since then his cold has improved, but he continues to have a cough and worsening asthma symptoms. He says that he has been using his rescue inhaler 3 times a day with little improvement. He is studying for an accounting exam and states that his asthma is keeping him up at night and making it hard for him to focus during the day. The patient admits to smoking tobacco. His smoking has increased from a half pack per day since he was 17 years old to 1 pack per day during the past month to cope with the stress of his exam. The patient's temperature is 99°F (37.2°C), blood pressure is 110/74 mmHg, pulse is 75/min, and respirations are 15/min with an oxygen saturation of 97% on room air. Physical examination is notable for mild expiratory wheezes bilaterally. Labs are obtained, as shown below:
Serum:
Na+: 144 mEq/L
Cl-: 95 mEq/L
K+: 4.3 mEq/L
HCO3-: 23 mEq/L
Urea nitrogen: 24 mg/dL
Glucose: 100 mg/dL
Creatinine: 1.6 mg/dL
Leukocyte count and differential:
Leukocyte count: 13,000/mm^3
Segmented neutrophils: 63%
Eosinophils: 15%
Basophils: < 1%
Lymphocytes: 20%
Monocytes: 1.3%
Hemoglobin: 13.5 g/dL
Hematocrit: 50%
Platelets: 200,000/mm^3
Urinalysis reveals proteinuria and microscopic hematuria. Which of the following is associated with the patient's most likely diagnosis?
Q417
A 39-year-old woman is brought to the emergency department in a semi-unconscious state by her neighbor who saw her lose consciousness. There was no apparent injury on the primary survey. She is not currently taking any medications. She has had loose stools for the past 3 days and a decreased frequency of urination. No further history could be obtained. The vital signs include: blood pressure 94/62 mm Hg, temperature 36.7°C (98.0°F), pulse 105/min, and respiratory rate 10/min. The skin appears dry. Routine basic metabolic panel, urine analysis, urine osmolality, and urine electrolytes are pending. Which of the following lab abnormalities would be expected in this patient?
Q418
A 25-year-old woman presents to the emergency department with palpitations, sweating, and blurry vision after playing volleyball on the beach. She denies chest pain and shortness of breath. She states that these episodes occur often, but resolve after eating a meal or drinking a sugary soda. Past medical history is unremarkable, and she takes no medications. Temperature is 37°C (98.6°F), blood pressure is 135/80 mm Hg, pulse is 102/min, and respirations are 18/min. Fingerstick blood glucose level is 42 mg/dL. ECG reveals sinus tachycardia. Urinalysis and toxicology are noncontributory. Appropriate medical therapy is administered and she is discharged with an appointment for a fasting blood draw within the week. Laboratory results are as follows:
Blood glucose 45 mg/dL
Serum insulin 20 microU/L (N: < 6 microU/L)
Serum proinsulin 10 microU/L (N: < 20% of total insulin)
C-peptide level 0.8 nmol/L (N: < 0.2 nmol/L)
Sulfonylurea Negative
IGF-2 Negative
What is the most likely cause of this patient's hypoglycemia?
Q419
A 21-year-old woman is admitted to the hospital for severe malnutrition with a BMI of 15 kg/m2. Past medical history is significant for chronic anorexia nervosa. During the course of her stay, she is treated with parenteral fluids and nutrition management. On the 4th day, her status changes. Her blood pressure is 110/75 mm Hg, heart rate is 120/min, respiratory rate is 25/min, and temperature is 37.0°C (98.6°F). On physical exam, her heart is tachycardic with a regular rhythm and her lungs are clear to auscultation bilaterally. She appears confused, disoriented, and agitated. Strength in her lower extremities is 4/5. What is the next step in management?
Q420
A 38-year-old woman comes to the physician because of a 10-month history of nonbloody diarrhea and recurrent episodes of flushing and wheezing. She does not take any medications. Physical examination shows a hyperpigmented rash around the base of her neck. Cardiac examination shows a grade 4/6, holosystolic murmur in the 5th intercostal space at the left midclavicular line. Echocardiography shows left-sided endocardial and valvular fibrosis with moderate mitral regurgitation; there are no septal defects or right-sided valvular defects. Urinalysis shows increased 5-hydroxyindoleacetic acid concentration. Further evaluation of this patient is most likely to show which of the following findings?
Gastroenterology US Medical PG Practice Questions and MCQs
Question 411: A 74-year-old man presents to the physician with a painful lesion over his right lower limb which began 2 days ago. He says that the lesion began with pain and severe tenderness in the area. The next day, the size of the lesion increased and it became erythematous. He also mentions that a similar lesion had appeared over his left lower limb 3 weeks earlier, but it disappeared after a few days of taking over the counter analgesics. There is no history of trauma, and the man does not have any known medical conditions. On physical examination, the physician notes a cordlike tender area with erythema and edema. There are no signs suggestive of deep vein thrombosis or varicose veins. Which of the following malignancies is most commonly associated with the lesion described in the patient?
A. Malignant melanoma
B. Basal cell carcinoma
C. Multiple myeloma
D. Adenocarcinoma of pancreas (Correct Answer)
E. Squamous cell carcinoma of head and neck
Explanation: ***Adenocarcinoma of pancreas***
- The patient's presentation of a migratory, tender, cord-like lesion with erythema and edema, known as **Trousseau's Syndrome**, is a classic paraneoplastic phenomenon.
- **Trousseau's Syndrome**, or migratory thrombophlebitis, is most commonly associated with **adenocarcinomas**, particularly those of the **pancreas**, lung, gastrointestinal tract, and prostate.
*Malignant melanoma*
- While melanoma can metastasize widely, it is not typically associated with **migratory thrombophlebitis** as a paraneoplastic syndrome.
- Melanoma presents primarily as a **skin lesion** with characteristic changes in size, color, or shape, not thrombotic episodes.
*Basal cell carcinoma*
- This is a **slow-growing, localized skin cancer** that rarely metastasizes and is not associated with paraneoplastic syndromes like Trousseau's.
- It typically presents as a **pearly nodule** or an ulcerating lesion on sun-exposed areas.
*Multiple myeloma*
- Multiple myeloma is a **plasma cell malignancy** primarily affecting bone marrow, leading to bone lesions, renal failure, and hypercalcemia.
- While it can cause hypercoagulability, it less commonly presents with **Trousseau's Syndrome** compared to adenocarcinomas.
*Squamous cell carcinoma of head and neck*
- Squamous cell carcinoma of the head and neck is a malignancy strongly associated with **smoking and alcohol use**.
- It is not a common cause of **migratory thrombophlebitis** as a paraneoplastic syndrome, although other paraneoplastic syndromes can occur.
Question 412: A 23-year-old woman presents with fever, chills, nausea, and urinary urgency and frequency. She says that her symptoms began 4 days ago and have progressively worsened. Her past medical history is significant for a 6-month history of recurrent urinary tract infections (UTIs). Her vital signs include: temperature 39.0°C (102.2°F), blood pressure 100/70 mm Hg, pulse 92/min, and respiratory rate 25/min. On physical examination, there is moderate left costovertebral angle tenderness. Laboratory findings are significant for the following:
WBC 8,500/mm3
RBC 4.20 x 106/mm3
Hematocrit 41.5%
Hemoglobin 13.0 g/dL
Platelet count 225,000/mm3
Urinalysis
Color Dark yellow
Clarity Turbid
pH 6.5
Specific gravity 1.026
Glucose None
Ketones None
Nitrites Positive
Leukocyte esterase Positive
Bilirubin Negative
Urobilirubin 0.6 mg/dL
Protein Trace
Blood None
WBC 25/hpf
Bacteria Many
Which of the following is the most likely diagnosis in this patient?
A. Acute obstructing nephrolithiasis
B. Pyelonephritis (Correct Answer)
C. Uncomplicated cystitis
D. Complicated cystitis
E. Renal abscess
Explanation: ***Pyelonephritis***
- The patient presents with **fever, chills, nausea, and costovertebral angle tenderness**, indicating an upper urinary tract infection.
- **Urinalysis shows nitrites, leukocyte esterase, WBCs (25/hpf), and many bacteria**, all consistent with infection that has spread to the kidneys.
- The **history of recurrent UTIs** increases risk for ascending infection.
*Acute obstructing nephrolithiasis*
- While **kidney stones** can cause similar pain, this patient's presentation includes **significant fever, chills, and positive signs of infection (nitrites, leukocyte esterase, WBCs in urine)**, which are not typical for uncomplicated nephrolithiasis.
- **Hematuria** would be a more prominent finding with nephrolithiasis, and it is absent here ("Blood None").
*Uncomplicated cystitis*
- **Cystitis** is a lower urinary tract infection, typically presenting with **dysuria, frequency, and urgency** without systemic symptoms like fever and chills.
- The presence of **fever, chills, nausea, and costovertebral angle tenderness** points to an upper UTI (pyelonephritis), not cystitis alone.
*Complicated cystitis*
- **Complicated cystitis** refers to bladder infection in patients with underlying conditions (e.g., pregnancy, diabetes, urological abnormalities) or recurrent infections.
- However, the presence of **fever, chills, and flank pain (costovertebral angle tenderness)** indicates kidney involvement, distinguishing pyelonephritis from a bladder infection.
*Renal abscess*
- **Renal abscess** can present with fever and flank pain, similar to pyelonephritis.
- However, patients with renal abscess typically appear **more toxic**, have **persistently high fevers despite antibiotics**, and often require **imaging (CT scan) for diagnosis**.
- The **clinical presentation and urinalysis findings** are more consistent with acute pyelonephritis, which responds well to antibiotic therapy.
Question 413: A 42-year-old woman is brought to the emergency department because of intermittent sharp right upper quadrant abdominal pain and nausea for the past 10 hours. She has vomited 3 times. There is no associated fever, chills, diarrhea, or urinary symptoms. She has 2 children who both attend high school. She appears uncomfortable. She is 165 cm (5 ft 5 in) tall and weighs 86 kg (190 lb). Her BMI is 32 kg/m2. Her temperature is 37.0°C (98.6°F), pulse is 100/min, and blood pressure is 140/90 mm Hg. She has mild scleral icterus. On physical examination, her abdomen is soft and nondistended, with tenderness to palpation of the right upper quadrant without guarding or rebound. Bowel sounds are normal. Laboratory studies show the following:
Blood
Hemoglobin count 14 g/dL
Leukocyte count 9,000 mm3
Platelet count 160,000 mm3
Serum
Alkaline phosphatase 238 U/L
Aspartate aminotransferase 60 U/L
Bilirubin
Total 2.8 mg/dL
Direct 2.1 mg/dL
Which of the following is the most appropriate next step in diagnosis?
A. Endoscopic retrograde cholangiopancreatography (ERCP)
B. Supine and erect X-rays of the abdomen
C. Computed tomography (CT) scan of the abdomen
D. Hepatobiliary iminodiacetic acid (HIDA) scan of the biliary tract
E. Transabdominal ultrasonography (Correct Answer)
Explanation: ***Transabdominal ultrasonography***
- This is the **initial diagnostic test of choice** for suspected **gallstones** or other biliary pathology due to its non-invasive nature, accessibility, and high sensitivity for detecting stones.
- The patient's presentation with **RUQ pain**, nausea, vomiting, obesity, and mild **scleral icterus** with elevated **alkaline phosphatase** and **direct bilirubin** is highly suggestive of **choledocholithiasis** or **cholecystitis**.
*Endoscopic retrograde cholangiopancreatography (ERCP)*
- **ERCP** is a **therapeutic procedure** used to remove stones from the common bile duct, rather than a primary diagnostic tool.
- It is an **invasive procedure** with risks such as pancreatitis and is reserved for cases where obstruction is confirmed and needs intervention.
*Supine and erect X-rays of the abdomen*
- **Plain X-rays** are not effective for diagnosing gallstones as only about **10-20% of gallstones are radiopaque**.
- While they can rule out other causes of abdominal pain like bowel obstruction or perforation, they are **not the primary imaging modality** for biliary issues.
*Computed tomography (CT) scan of the abdomen*
- A **CT scan** is less sensitive than ultrasound for detecting gallstones and is associated with **radiation exposure**.
- It might be used if ultrasound findings are inconclusive or if there is concern for other intra-abdominal pathology, but it is **not the initial test of choice** for suspected cholelithiasis.
*Hepatobiliary iminodiacetic acid (HIDA) scan of the biliary tract*
- A **HIDA scan** is primarily used to diagnose **acute cholecystitis** (inflammation of the gallbladder) by assessing gallbladder emptying or obstruction of the cystic duct.
- While useful for acute cholecystitis, it is **not the first-line diagnostic test** for simply detecting gallstones or common bile duct stones, for which ultrasound is superior.
Question 414: A 23-year-old woman comes to the emergency department for increasing abdominal pain and confusion for 3 days. The pain is constant and she describes it as 8 out of 10 in intensity. She has the strong feeling that she is being watched. She has not had a bowel movement for 2 days. She began experiencing tingling in parts of her lower extremities 4 hours ago. She consumed a large number of alcoholic beverages prior to the onset of the abdominal pain. Her temperature is 38°C (100.8°F), pulse is 113/min, and blood pressure is 148/88 mm Hg. She appears distracted and admits to hearing whispering intermittently during the examination, which shows a distended abdomen and mild tenderness to palpation diffusely. There is no guarding or rebound tenderness present. Bowel sounds are decreased. There is weakness of the iliopsoas and hamstring muscles. Sensation is decreased over the lower extremities. Deep tendon reflexes are 2+ in the lower extremities. Mental status examination shows she is oriented only to person and place. A complete blood count and serum concentrations of electrolytes, glucose, creatinine are within the reference range. Which of the following is the most appropriate next step in management?
A. Haloperidol therapy
B. Glucose
C. Chloroquine
D. Hemin therapy (Correct Answer)
E. Chlordiazepoxide
Explanation: **Hemin therapy**
- This patient presents with an acute neurovisceral crisis, characterized by **abdominal pain**, **psychiatric symptoms** (confusion, paranoia, hallucinations), **tachycardia**, **hypertension**, **constipation**, and **neuropathy** (tingling, weakness, decreased sensation). These symptoms are classic for **acute intermittent porphyria (AIP)**.
- **Hemin therapy** is the most effective treatment for an acute attack of AIP, as it replenishes the heme pool, thereby downregulating **ALA synthase** and reducing the production of neurotoxic porphyrin precursors.
*Haloperidol therapy*
- While **haloperidol** can be used to manage acute psychosis and agitation, it would only address a single symptom and would not treat the underlying cause of the patient's multi-systemic illness.
- Furthermore, certain medications, including some antipsychotics, can exacerbate porphyria attacks and should be used with caution, if at all.
*Glucose*
- **Glucose infusion** can sometimes be used as an initial measure in porphyria attacks to help suppress ALA synthase activity by increasing hepatic glucose delivery, but it is less effective than hemin, especially in severe cases.
- Glucose alone would not be sufficient for the severe and rapidly progressive symptoms seen in this patient.
*Chloroquine*
- **Chloroquine** is an antimalarial drug that can induce or exacerbate porphyria attacks, particularly in patients with **porphyria cutanea tarda (PCT)**.
- It is completely contraindicated in this setting and would worsen the patient's condition.
*Chlordiazepoxide*
- **Chlordiazepoxide** is a benzodiazepine used to treat anxiety and alcohol withdrawal but would not address the underlying pathology of an acute porphyria attack.
- While it may sedate the patient, it would not resolve the abdominal pain, neuropathy, or other systemic manifestations.
Question 415: A 40-year-old woman, gravida 2, para 2, comes to the physician because of fatigue, nausea, joint pain, and mild flank pain for 2 months. She has refractory acid reflux and antral and duodenal peptic ulcers for which she takes omeprazole. She also has chronic, foul-smelling, light-colored diarrhea. Five years ago she was successfully treated for infertility with bromocriptine. She reports recently feeling sad and unmotivated at work. She does not smoke or drink alcohol. She is 175 cm (5 ft 9 in) tall and weighs 100 kg (220 lb); BMI is 32.7 kg/m2. Her temperature is 37°C (98.8°F), pulse is 78/min, and blood pressure is 150/90 mm Hg. Cardiopulmonary examination shows no abnormalities. The abdomen is moderately distended and diffusely tender to palpation. There is mild costovertebral angle tenderness. Her serum calcium concentration is 12 mg/dL, phosphorus concentration is 2 mg/dL, and parathyroid hormone level is 900 pg/mL. Abdominal ultrasound shows mobile echogenic foci with acoustic shadowing in her ureteropelvic junctions bilaterally. A mutation in which of the following genes is most likely present in this patient?
A. MEN1 (Correct Answer)
B. NF2
C. VHL
D. C-Kit
E. RET
Explanation: ***MEN1***
- This patient presents with primary **hyperparathyroidism** (high calcium, low phosphorus, very high PTH), a history of **infertility treated with bromocriptine** (suggesting a **prolactinoma**), and **refractory peptic ulcers** (suggesting **Zollinger-Ellison syndrome** due to gastrinoma). These three features (parathyroid adenoma, pituitary adenoma, and gastrinoma) are the classic triad of **Multiple Endocrine Neoplasia type 1 (MEN1)**, caused by a mutation in the *MEN1* gene.
- The additional symptoms like fatigue, nausea, joint pain, flank pain, and kidney stones are all consistent with chronic hypercalcemia. The foul-smelling, light-colored diarrhea could be related to severe reflux/Zollinger-Ellison syndrome or a secondary malabsorption issue.
*NF2*
- Mutations in the *NF2* gene cause **Neurofibromatosis type 2**, which is characterized by **bilateral vestibular schwannomas**, meningiomas, and ependymomas.
- This patient's symptoms do not align with the typical clinical presentation of neurofibromatosis type 2.
*VHL*
- Mutations in the *VHL* gene cause **Von Hippel-Lindau disease**, characterized by **hemangioblastomas** of the cerebellum, retina, and spinal cord, **renal cell carcinoma**, pheochromocytomas, and pancreatic neuroendocrine tumors.
- While pancreatic neuroendocrine tumors can occur, the constellation of hyperparathyroidism, pituitary adenoma, and gastrinoma is not characteristic of VHL disease.
*C-Kit*
- Mutations in the *C-Kit* gene are primarily associated with **gastrointestinal stromal tumors (GISTs)** and some forms of mastocytosis.
- This gene mutation does not explain the patient's complex endocrine presentation with hyperparathyroidism, pituitary tumor, and gastrinoma.
*RET*
- Mutations in the *RET* gene are associated with **Multiple Endocrine Neoplasia type 2 (MEN2)**.
- **MEN2A** includes **medullary thyroid carcinoma**, pheochromocytoma, and primary hyperparathyroidism (but usually less severe than in MEN1). **MEN2B** includes medullary thyroid carcinoma, pheochromocytoma, and distinctive physical features like marfanoid habitus and mucosal neuromas, but not pituitary or gastrinomas. This patient's symptoms are not consistent with MEN2.
Question 416: A 27-year-old man presents to his primary care physician with worsening cough and asthma. The patient reports that he was in his usual state of health until 1 month ago, when he developed a cold. Since then his cold has improved, but he continues to have a cough and worsening asthma symptoms. He says that he has been using his rescue inhaler 3 times a day with little improvement. He is studying for an accounting exam and states that his asthma is keeping him up at night and making it hard for him to focus during the day. The patient admits to smoking tobacco. His smoking has increased from a half pack per day since he was 17 years old to 1 pack per day during the past month to cope with the stress of his exam. The patient's temperature is 99°F (37.2°C), blood pressure is 110/74 mmHg, pulse is 75/min, and respirations are 15/min with an oxygen saturation of 97% on room air. Physical examination is notable for mild expiratory wheezes bilaterally. Labs are obtained, as shown below:
Serum:
Na+: 144 mEq/L
Cl-: 95 mEq/L
K+: 4.3 mEq/L
HCO3-: 23 mEq/L
Urea nitrogen: 24 mg/dL
Glucose: 100 mg/dL
Creatinine: 1.6 mg/dL
Leukocyte count and differential:
Leukocyte count: 13,000/mm^3
Segmented neutrophils: 63%
Eosinophils: 15%
Basophils: < 1%
Lymphocytes: 20%
Monocytes: 1.3%
Hemoglobin: 13.5 g/dL
Hematocrit: 50%
Platelets: 200,000/mm^3
Urinalysis reveals proteinuria and microscopic hematuria. Which of the following is associated with the patient's most likely diagnosis?
A. IgA deposits
B. Smoking
C. c-ANCA levels
D. Hepatitis B surface antigen
E. p-ANCA levels (Correct Answer)
Explanation: ***p-ANCA levels***
- The patient presents with asthma, sinusitis-like symptoms (prior cold followed by worsening cough/asthma), eosinophilia (15%), and renal involvement (proteinuria, hematuria, elevated creatinine). This constellation of symptoms is highly suggestive of **Eosinophilic Granulomatosis with Polyangiitis (EGPA)**, formerly known as Churg-Strauss Syndrome.
- Approximately 30-40% of EGPA patients are positive for **p-ANCA (anti-myeloperoxidase antibodies)**, which are associated with the vasculitic phase and renal involvement.
*IgA deposits*
- **IgA deposits** are characteristic of **IgA nephropathy (Berger's disease)** or **Henoch-Schönlein purpura** (now IgA vasculitis), which typically present with hematuria and proteinuria, sometimes after an upper respiratory infection.
- However, these conditions do not typically cause severe asthma, significant eosinophilia, or a systemic vasculitis picture with pulmonary involvement as seen in this patient.
*Smoking*
- While the patient is a smoker and smoking can exacerbate asthma and contribute to chronic lung disease, it is not an *associated factor* with the underlying diagnosis of EGPA itself.
- Smoking is a risk factor for many respiratory illnesses but doesn't specifically point to EGPA in the context of the given clinical and laboratory findings.
*c-ANCA levels*
- **c-ANCA (anti-proteinase 3 antibodies)** are primarily associated with **Granulomatosis with Polyangiitis (GPA)**, formerly Wegener's granulomatosis.
- While GPA can present with kidney involvement and pulmonary symptoms, it typically involves the upper airways (sinusitis, otitis), lungs, and kidneys, but is usually *not* associated with severe asthma or prominent eosinophilia, which are key features in this patient.
*Hepatitis B surface antigen*
- **Hepatitis B surface antigen** positivity is associated with **polyarteritis nodosa (PAN)** due to immune complex deposition.
- PAN is a necrotizing vasculitis that can affect multiple organs but typically spare the lungs and is not associated with asthma or eosinophilia.
Question 417: A 39-year-old woman is brought to the emergency department in a semi-unconscious state by her neighbor who saw her lose consciousness. There was no apparent injury on the primary survey. She is not currently taking any medications. She has had loose stools for the past 3 days and a decreased frequency of urination. No further history could be obtained. The vital signs include: blood pressure 94/62 mm Hg, temperature 36.7°C (98.0°F), pulse 105/min, and respiratory rate 10/min. The skin appears dry. Routine basic metabolic panel, urine analysis, urine osmolality, and urine electrolytes are pending. Which of the following lab abnormalities would be expected in this patient?
A. Serum blood urea nitrogen/creatinine (BUN/Cr) > 20 (Correct Answer)
B. Urine osmolality < 350 mOsm/kg
C. Fractional excretion of sodium (FENa) > 2%
D. Urine Na+ > 40 mEq/L
E. Serum creatinine < 1 mg/dL
Explanation: ***Serum blood urea nitrogen/creatinine (BUN/Cr) > 20***
- The patient presents with classic signs of **hypovolemia**, including hypotension, tachycardia, dry skin, and decreased urine output, likely due to significant fluid loss from diarrheal illness. This state leads to **prerenal azotemia**.
- In prerenal azotemia, the kidneys reabsorb more water and urea to conserve fluid, leading to a disproportionate rise in BUN compared to creatinine, resulting in a **BUN/Cr ratio typically > 20:1**.
*Urine osmolality < 350 mOsm/kg*
- This value indicates the kidney is actively excreting dilute urine, which would be expected in conditions like **diabetes insipidus** or **excessive fluid intake**.
- In response to hypovolemia, the kidneys attempt to conserve water, leading to the excretion of **highly concentrated urine**, with osmolality typically **> 500 mOsm/kg**.
*Fractional excretion of sodium (FENa) > 2%*
- An FENa > 2% suggests **intrinsic renal damage** (acute tubular necrosis) where the kidneys cannot effectively reabsorb sodium.
- In prerenal azotemia, the kidneys are structurally intact and actively conserve sodium to maintain circulating volume, leading to an **FENa < 1%**.
*Urine Na+ > 40 mEq/L*
- A urine sodium concentration above 40 mEq/L is observed in **intrinsic kidney injury** or during **diuretic use**, where sodium reabsorption is impaired.
- With hypovolemia, the kidneys avidly reabsorb sodium, striving to restore volume. This results in a **low urine sodium concentration**, typically **< 20 mEq/L**.
*Serum creatinine < 1 mg/dL*
- While a serum creatinine < 1 mg/dL *could* be normal for some individuals, in the context of significant dehydration and prerenal azotemia, one would expect a **rise in serum creatinine** alongside BUN.
- The patient's condition, characterized by hypovolemia and decreased renal perfusion, leads to **elevated serum creatinine**.
Question 418: A 25-year-old woman presents to the emergency department with palpitations, sweating, and blurry vision after playing volleyball on the beach. She denies chest pain and shortness of breath. She states that these episodes occur often, but resolve after eating a meal or drinking a sugary soda. Past medical history is unremarkable, and she takes no medications. Temperature is 37°C (98.6°F), blood pressure is 135/80 mm Hg, pulse is 102/min, and respirations are 18/min. Fingerstick blood glucose level is 42 mg/dL. ECG reveals sinus tachycardia. Urinalysis and toxicology are noncontributory. Appropriate medical therapy is administered and she is discharged with an appointment for a fasting blood draw within the week. Laboratory results are as follows:
Blood glucose 45 mg/dL
Serum insulin 20 microU/L (N: < 6 microU/L)
Serum proinsulin 10 microU/L (N: < 20% of total insulin)
C-peptide level 0.8 nmol/L (N: < 0.2 nmol/L)
Sulfonylurea Negative
IGF-2 Negative
What is the most likely cause of this patient's hypoglycemia?
A. Delta cell tumor of the pancreas
B. Heat stroke
C. Exogenous insulin
D. Beta cell tumor of the pancreas (Correct Answer)
E. Alpha cell tumor of the pancreas
Explanation: ***Beta cell tumor of the pancreas***
- The patient's symptoms of **palpitations, sweating, and blurry vision** developing after exertion, coupled with symptom resolution after eating, are classic for **hypoglycemia**.
- The laboratory findings, including **low blood glucose (45 mg/dL)**, **elevated serum insulin (20 microU/L)**, **elevated C-peptide (0.8 nmol/L)**, and **proinsulin levels (10 microU/L)**, are highly indicative of an **insulin-producing tumor (insulinoma)**, which originates from the pancreatic beta cells.
*Delta cell tumor of the pancreas*
- A **delta cell tumor (somatostatinoma)** typically causes symptoms related to **somatostatin excess**, such as **gallstones, diabetes mellitus, steatorrhea, and weight loss**.
- These tumors do not primarily cause hypoglycemia; in fact, somatostatin generally inhibits insulin release.
*Heat stroke*
- **Heat stroke** is characterized by a **core body temperature >40°C (104°F)** and central nervous system dysfunction (e.g., altered mental status, seizures).
- The patient's temperature is normal, and her symptoms are directly linked to hypoglycemia, not heat exposure.
*Exogenous insulin*
- If the patient were taking **exogenous insulin**, her **C-peptide level would be suppressed or very low** because C-peptide is co-secreted with endogenous insulin.
- The **elevated C-peptide level** in this case rules out surreptitious insulin use as the cause of her hypoglycemia.
*Alpha cell tumor of the pancreas*
- An **alpha cell tumor (glucagonoma)** secretes excess **glucagon**, which **raises blood glucose levels**.
- This would typically lead to **hyperglycemia**, not the hypoglycemia observed in this patient.
Question 419: A 21-year-old woman is admitted to the hospital for severe malnutrition with a BMI of 15 kg/m2. Past medical history is significant for chronic anorexia nervosa. During the course of her stay, she is treated with parenteral fluids and nutrition management. On the 4th day, her status changes. Her blood pressure is 110/75 mm Hg, heart rate is 120/min, respiratory rate is 25/min, and temperature is 37.0°C (98.6°F). On physical exam, her heart is tachycardic with a regular rhythm and her lungs are clear to auscultation bilaterally. She appears confused, disoriented, and agitated. Strength in her lower extremities is 4/5. What is the next step in management?
A. MRI of the brain
B. Administer insulin
C. Measure electrolytes (Correct Answer)
D. Arrange for outpatient counseling
E. Doppler ultrasound on lower extremities
Explanation: ***Measure electrolytes***
- The patient's presentation with **confusion, disorientation, agitation**, and **lower extremity weakness** after refeeding for severe **malnutrition** is highly suggestive of **refeeding syndrome**. This syndrome is characterized by severe electrolyte shifts, particularly **hypophosphatemia**, **hypokalemia**, and **hypomagnesemia**.
- Measuring electrolytes immediately is crucial to diagnose and then correct these imbalances, which can lead to life-threatening complications like **cardiac arrhythmias**, **respiratory failure**, and **seizures**.
*MRI of the brain*
- While neurological symptoms are present, a brain MRI is not the immediate first step given the context of refeeding in a severely malnourished patient.
- The symptoms are more consistent with **metabolic derangements** associated with **refeeding syndrome** than an acute primary neurological event.
*Administer insulin*
- Administering insulin without knowing the patient's glucose or electrolyte status could be dangerous, especially given the increased risk of **hypokalemia** and **hypophosphatemia** in refeeding syndrome, which insulin can exacerbate.
- Refeeding syndrome typically involves glucose shifts, but **hypoglycemia** is not the primary immediate concern, and hyperinsulinemia in this context can cause cellular uptake of electrolytes leading to further depletion.
*Arrange for outpatient counseling*
- The patient is acutely ill and experiencing a potentially life-threatening complication requiring immediate medical intervention.
- **Outpatient counseling** is not appropriate for an acute hospital admission with severe, rapidly changing symptoms.
*Doppler ultrasound on lower extremities*
- While immobility can increase the risk of deep vein thrombosis (DVT), the patient's symptoms of **confusion, agitation, tachycardia, tachypnea**, and **weakness** are not primary indicators of DVT.
- The clinical picture points strongly towards **metabolic complications** of refeeding.
Question 420: A 38-year-old woman comes to the physician because of a 10-month history of nonbloody diarrhea and recurrent episodes of flushing and wheezing. She does not take any medications. Physical examination shows a hyperpigmented rash around the base of her neck. Cardiac examination shows a grade 4/6, holosystolic murmur in the 5th intercostal space at the left midclavicular line. Echocardiography shows left-sided endocardial and valvular fibrosis with moderate mitral regurgitation; there are no septal defects or right-sided valvular defects. Urinalysis shows increased 5-hydroxyindoleacetic acid concentration. Further evaluation of this patient is most likely to show which of the following findings?
A. Tumor in the descending colon with hepatic metastasis
B. Tumor in the left atrium with hepatic metastasis
C. Tumor in the pancreas without metastasis
D. Tumor in the lung without metastasis (Correct Answer)
E. Tumor in the appendix without metastasis
Explanation: ***Tumor in the lung without metastasis***
- The patient presents with **carcinoid syndrome** symptoms (flushing, wheezing, diarrhea, hyperpigmented rash, increased 5-HIAA), but the **left-sided valvular fibrosis** (mitral regurgitation) is atypical for classic carcinoid, which usually affects the right heart.
- Left-sided heart involvement in carcinoid syndrome occurs when a **primary bronchial carcinoid tumor** directly releases serotonin into the pulmonary veins and systemic circulation, bypassing both hepatic metabolism and the right heart, allowing it to reach the left heart valves before inactivation.
- This is the key distinguishing feature: only bronchial/lung carcinoids can cause left-sided cardiac disease because they drain into pulmonary veins rather than the portal or systemic venous system.
*Tumor in the descending colon with hepatic metastasis*
- A tumor in the descending colon would release serotonin into the **portal circulation**, which would then be **metabolized by the liver** before reaching the systemic circulation.
- Even with liver metastases releasing serotonin into hepatic veins, it would enter the **right heart first** via the IVC, causing **right-sided valvular disease** (tricuspid regurgitation, pulmonary stenosis), not left-sided mitral regurgitation.
- The lungs inactivate serotonin, protecting the left heart in GI carcinoid cases.
*Tumor in the left atrium with hepatic metastasis*
- Primary cardiac tumors (myxomas) do not produce serotonin and would not explain the systemic symptoms of **carcinoid syndrome**, such as flushing, wheezing, or elevated 5-HIAA.
- This combination is anatomically and pathophysiologically implausible for carcinoid syndrome.
*Tumor in the pancreas without metastasis*
- A pancreatic neuroendocrine tumor (PNET) can produce serotonin, but without hepatic metastases, the serotonin released into the portal system would be **metabolized by the liver**, preventing systemic carcinoid syndrome.
- Even with metastases, it would typically cause **right-sided heart disease** as serotonin from liver metastases enters the right heart first.
- The absence of metastasis makes this highly unlikely to cause the clinical syndrome.
*Tumor in the appendix without metastasis*
- Appendiceal carcinoid tumors, especially without metastasis, are generally **asymptomatic** or cause only local symptoms, as the serotonin produced drains into the portal system and is effectively metabolized by the liver.
- They would not cause systemic carcinoid syndrome, and certainly not isolated left-sided cardiac involvement.