USMLE USMLE-STEP-2 Online Practice Questions and Exam Preparation

USMLE USMLE-STEP-2 Online Questions & Answers

• Question 111:

  A 65-year-old woman presents to the physician's office with a 6-month history of epigastric discomfort, poor appetite, and 10-lb weight loss. Past history is pertinent for hypertension, diabetes, a 30 pack-year smoking history, and occasional alcohol intake. Examination is unremarkable except for mild epigastric tenderness to deep palpation. An abdominal ultrasound reveals cholelithiasis, and one view of a UGI x-ray series is shown in the figure.

  

  Which of the following is the most appropriate next step in management?

  A. H2 blockers with re-evaluation by UGI in 6 months
  B. vagotomy and pyloroplasty
  C. total gastrectomy
  D. endoscopy
  E. CT scan
  D. endoscopy

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  Explanation

  The symptoms of gastric cancer are nonspecific and may mimic those of such benign conditions as benign gastric ulcer. Pain, nausea, anorexia, and weight loss are common nonspecific symptoms. A UGI series shows a gastric ulcer that has characteristics of malignancy, including an intraluminal crater with nodular margins. Agastric diverticulum would extend as a protrusion beyond the gastric lumen. The duodenum is not well visualized in the x-ray, making the diagnosis of duodenal disease difficult.

  Afistula would be suggested by contrast filling of the gallbladder and biliary tree. Given the x-ray findings suggestive of malignancy, the next step would be to obtain a tissue diagnosis for confirmation by endoscopy. Once malignancy is confirmed, a CT scan would be helpful to evaluate for liver metastasis and extent of disease. Operative intervention may be determined at that time, usually a subtotal or total gastrectomy. Vagotomy and pyloroplasty would not be appropriate for gastric cancer. Medical therapy with H2 blockers may improve the patient's symptoms but should not delay endoscopy and biopsy

• Question 112:

  A70-year-old man presents to urgent care complaining of a painful, swollen left knee. He previously has had no problems with this knee. Three days prior to onset, he went out dancing for 23 hours but recalls no specific injury. Examination of the knee reveals a moderatesized effusion and mild pain with any range of motion. Plain x-ray shows no fracture. Which of the following is the best next management?

  A. MRI of knee
  B. aspiration of effusion fluid
  C. rest, ice, and leg elevation
  D. physical therapy referral
  E. arthroscopy
  B. aspiration of effusion fluid

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  Explanation

  The presence of effusion generally signifies significant disease. Aspiration of the effusion will help in evaluation for hemarthrosis, septic arthritis, and inflammatory crystal disease. Each of these is important to identify and treat early. An MRI and/or arthroscopy would be later considerations.

  Orthopedic referral likely would be necessary.

• Question 113:

  The mother of a 3-year-old girl brings her daughter to see you because the girl developed breasts 6 months ago. The girl has had no vaginal bleeding, and there is no pubic hair. She takes no medication.

  Which of the following is the most appropriate next diagnostic step?

  A. an ultrasound of the pelvis
  B. a pelvic examination under general anesthesia
  C. computed tomography (CT) scan of her head
  D. a serum estradiol concentration
  E. a serum follicle-stimulating hormone (FSH) concentration
  D. a serum estradiol concentration

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  Explanation

  Breast development in an infant or young child is the consequence of increased estrogen secretion, exposure to exogenous estrogens, or increased response of breast tissue to normal, prepubertal amounts of estrogen. After excluding exposure to exogenous estrogens (e.g., OCs, estrogen creams), increased response to estrogen is more common than increased estrogen secretion from the ovaries or adrenal glands when breast development is the only sign of precocious puberty. The uterus and adnexa can be palpated abdominally in prepubertal girls if they are pathologically enlarged. For this reason, an estrogen-secreting ovarian tumor (granulosa cell is the most common type) is usually palpable, and an ultrasound examination is unnecessary. For the same reason, a pelvic examination under anesthesia is not necessary, especially if the serum estradiol concentration is normal. CT scan of the head and a serum FSH concentration are unnecessary if breast development is the only sign of precocious puberty, and the serum estradiol concentration is normal in the prepubertal range.

• Question 114:

  A 33-year-old woman experiences visions of flashing lights followed by throbbing left-sided temporal pain and nausea. Which of the following is the most likely diagnosis?

  A. tension headache
  B. transient ischemic attack (TIA)
  C. temporal arteritis
  D. migraine headache
  E. cluster headache
  D. migraine headache

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  Explanation

  The typical migraine attack consists of a visual aura with flashes, scintillating scotomata (field loss), or fortification spectra followed by a throbbing unilateral temporal headache. There may be associated vestibular, GI, or neurologic symptoms. Attacks are often precipitated by stress, fatigue, or foods that contain tyramine (e.g., cheese, yogurt, nuts) or phenylethylamine (wine, chocolate). Symptoms peak within an hour of onset and persist for hours to days. A positive family history is found in as many as 50% of cases. Tension headaches are more often bilateral and described as band like or vise like and are not usually associated with visual auras. TIAs more typically present as transient monocular blindness without aura or headache. Temporal arteritis may present as painless loss of vision without aura, but is usually in older people.

  Cluster headaches are much more common in men. Sumatriptan and the other triptans work by inhibiting the release of vasoactive peptides, promoting vasoconstriction, and blocking brainstem pain pathways. Sumatriptan comes in oral, injectable, and nasal spray form. Ergotamine tartrate, antiemetics, and analgesics may also be used in the acute treatment of migraine headache. Prophylactic medications such as beta-blockers, tricyclic antidepressants, calcium channel blockers, and anticonvulsants are ineffective for acute attacks. Avoidance of known precipitants and control of stress are also important in prevention.

• Question 115:

  A 30-year-old asymptomatic male presents to your office because his father just had a heart attack. He is concerned that he may have inherited his father's condition because a cholesterol level test done at his work site last year was 220 mg/dL. You review his history and find that he smokes 25 cigarettes a day, eats mostly at fast food restaurants, sits at a desk job, and has no regular moderate intensity physical activities. His blood pressure is 130/85 mmHg and his body mass index (BMI) is 26.

  Which of the following is the best first recommendation?

  A. electrocardiography (ECG)
  B. ECG and an exercise treadmill test (ETT)
  C. a diet for weight loss
  D. commencement of a daily exercise routine
  E. antihypertensive medication
  D. commencement of a daily exercise routine

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  Explanation

  The USPSTF does not recommend ECG or ETT in asymptomatic patients. A BMI greater than 27 is associated with increased mortality. The U.S. Surgeon General recommends a program of moderate exercise most days of the week.

• Question 116:

  A 1-day-old infant who received silver nitrate eye drops in the delivery room is suffering from bilateral purulent conjunctival discharge. Which of the following is the most likely cause of this child's condition?

  A. N. gonorrhoeae infection
  B. herpes simplex infection
  C. nasolacrimal duct obstruction
  D. chemical irritation
  E. Pseudomonas infection
  D. chemical irritation

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  Explanation

  Silver nitrate, the traditional prophylactic treatment for the neonate's eyes, is very effective against gonorrheal ophthalmitis. These drops are not effective against the most common cause of neonatal conjunctivitis, C. trachomatis, which requires erythromycin or tetracycline for eradication. Silver nitrate is commonly associated with the sterile purulent discharge of chemical conjunctivitis. HSV can cause neonatal conjunctivitis, but its occurrence on the first day of life would be unusual. Pseudomonas conjunctivitis generally is hospital acquired, occurring in ill infants receiving mechanical ventilation. Nasolacrimal duct obstruction is a transient structural anomaly that may be accompanied by persistent tearing and occasional purulent discharge. The condition is usually unilateral and clears within 69 months after birth. Rarely, duct probing or surgery is necessary because of persistent stenosis beyond 1 year of age or for repeated infections.

• Question 117:

  Select the appropriate incubation period of the Pertussis infectious disease of childhood.

  A. 16 days
  B. 78 days
  C. 810 days
  D. 1021 days
  E. 3050 days
  F. 120180 days
  C. 810 days

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  Explanation

  The incubation period for diphtheria is 17 days. The incubation period for chicken pox is 1021 days, average 14. Infectious mononucleosis, caused by the Epstein-Barr virus, has an estimated incubation period of 3050 days. The incubation period following infection by the mumps virus is usually 1618 days but, like chicken pox, may vary from 14 to 25 days. Pertussis has a shorter incubation period, usually 710 days, with a variation of 421 days. The usual period from contamination with tetanus spores to clinical symptoms is generally 68 days. For rubella, the incubation period is from 14 to 21 days, but usually ranges from 16 to 18 days.

• Question 118:

  A 31-year-old primigravida develops gestational diabetes mellitus and is managed appropriately during pregnancy. She asks you about the consequences of gestational diabetes to her and her fetus. Which one of the following statements is correct?

  A. The risk of fetal anomalies is increased.
  B. The risk of stillbirth is increased if her fasting blood sugars are elevated.
  C. The risk of a growth-restricted newborn is increased.
  D. Insulin is the preferred treatment to maintain euglycemia.
  E. The risk of fetal macrosomia is not increased with gestational diabetes.
  B. The risk of stillbirth is increased if her fasting blood sugars are elevated.

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  Explanation

  Unlike women with overt or pregestational diabetes mellitus, the risk of fetal anomalies is not increased in women with gestational diabetes. Stillbirth rates are increased in women with gestational diabetes if their fasting plasma glucose concentrations are elevated, but not with elevated postprandial glucose concentrations only. The risk of a growth-restricted infant is increased in women with long-standing diabetes and vascular disease, but not in women with gestational diabetes. There is a slight increase in the frequency of fetal macrosomia (birth weight over 4000 g), though shoulder dystocia and brachial plexus injury are infrequent.

• Question 119:

  Which of the following is the most appropriate evaluative procedure for an otherwise normal 7-day-old boy with perineal hypospadias?

  A. renal ultrasonography
  B. serum creatinine determination
  C. cystography
  D. circumcision
  E. intravenous pyelography (IVP)
  A. renal ultrasonography

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  Explanation

  Children with more severe cases of hypospadias have an increased incidence of concomitant urinary tract anomalies and require careful evaluation. Ultrasonography is a safe and noninvasive procedure that is sensitive in the diagnosis of neonatal urinary tract pathology. It is a better choice than either IVP or cystography which use contrast media and radiation. Serum creatinine determinations are a measure of renal function and are unnecessary in an otherwise healthy child. Circumcision is not indicated in children with hypospadias. In fact, it may be contraindicated in cases of second- or third-degree hypospadias, in which the prepuce can be used to construct an absent distal segment of urethra.

• Question 120:

  A 36-year-old female complains of 5 days of fever, nasal congestion, sinus pressure, and postnasal drip. On examination, nasal discharge is yellow and the posterior pharynx is slightly erythematous. Tapping over the maxillary sinuses elicits mild pain. Which of the following is the most appropriate treatment for this patient?

  A. treatment of symptoms (analgesics, antipyretics, decongestants)
  B. a 7-day course of amoxicillin
  C. a 10-day course of amoxicillin clavulanic acid
  D. a 14-day course of clarithromycin
  A. treatment of symptoms (analgesics, antipyretics, decongestants)

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  Explanation

  The Clinical Practice Guidelines of the American College of Physicians (endorsed by Centers for Disease Control [CDC], American Academy of Family Physicians, and the Infectious Diseases Society of America) state that most cases of acute sinusitis in the ambulatory setting are due to viral infection and do not require antibiotic treatment or radiography. Therapy should be targeted toward symptoms and often include decongestants, antipyretics, and analgesics. Antibiotic treatment should be reserved for patients who have symptoms that persist or worsen (generally for more than 7 days)