USMLE USMLE-STEP-3 Online Practice Questions and Exam Preparation

USMLE USMLE-STEP-3 Online Questions & Answers

• Question 701:

  A 38-year-old married female is brought in to the primary care clinic by her husband. She is minimally responsive to questioning, head bowed, and staring at the floor. Most of the history is obtained from her spouse. He denies any known personal or family history of mental illness, but he claims for the past several months his wife has become increasingly depressed and withdrawn. Instead of taking part in her usual hobbies, she is lying around the house. "She tosses and turns" throughout the night. Her husband ensures that she eats a limited amount of food, but she has lost a significant amount of weight. She has been ruminating about guilty feelings regarding a number of issues and recently has been speaking about suicide, although she has no plan or intent. She has refused to come in to see a doctor. Her husband insisted that she come today, as she informed him that the devil has possessed her and told her she will "go to hell."

  What is her most likely diagnosis?

  A. bipolar disorder, depressed, with psychotic features
  B. delusional disorder, somatic type
  C. major depressive disorder with psychotic features
  D. schizoaffective disorder, depressed type
  E. schizophrenia, paranoid type
  C. major depressive disorder with psychotic features

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  Explanation

  While patients with bipolar depression do present with psychotic features, this individual does not give any history of manic episodes, making the diagnosis difficult at this time. The bizarre delusions (those that cannot possibly exist in life) and auditory hallucinations that this patient has are not consistent with delusional disorder. Schizoaffective disorder, depressed type, includes both psychotic as well as depressive symptoms. However, the psychotic symptoms must last at least 1 month and occur in the absence of a depressed mood. The diagnosis of schizophrenia also requires at least 1 month of active psychosis but a total of 6 months of attenuated or residual symptoms. Although a depressed mood is very commonly seen in schizophrenia, the total duration of depression is brief overall compared to the psychotic symptoms. This patient presents with major depression with psychotic features, consisting of a depressed mood with neurovegetative symptoms for at least 2 weeks, as well as psychotic symptoms, which are only present along with the mood symptoms (DSM IV-TR).

  Mood stabilizers alone or with antipsychotic medications are not the first-line treatments for major depression with psychotic features, but rather for mania with or without psychotic features. Studies have demonstrated that the combination of antidepressants and antipsychotics is more effective in treating major depression with psychotic features than either pharmacotherapy alone.

• Question 702:

  A 60-year-old male developed painless hematuria. On further clinical evaluation, a CT scan showed a 7 cm mass on the lower pole of the right kidney. What would be your most likely diagnosis in this case?

  A. neuroblastoma
  B. medullary fibroma
  C. Wilms tumor
  D. transitional cell carcinoma
  E. renal cell carcinoma
  E. renal cell carcinoma

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  Explanation

  The most important and frequent cause of painless hematuria is renal cell carcinoma. This symptom is usually associated with a palpable mass on the flank, as well as costovertebral pain. Occasionally, renal cell carcinomas are associated with a paraneoplastic syndrome, which includes polycythemia, hypercalcemia, hypertension, feminization or masculinization, Cushing syndrome, and so on. The other answers listed are mostly seen in children. Transitional cell carcinoma is rarer than renal cell carcinoma and medullary fibroma is a benign tumor.

• Question 703:

  A 65-year-old man presents to your office for evaluation of abdominal pain. The patient states that he has epigastric pain that radiates to his back. The pain is worse with eating and improves with fasting. The pain has been present for 6 months and is gradually worsening. The patient has lost 15 lbs but feels his oral intake has been adequate. He complains of greasy stools and frequent thirst and urination. Examination reveals a thin male with temporal wasting and oderate abdominal pain with palpation. The patient consumes approximately 1015 beers per day and smokes a pack of cigarettes per day for the past 20 years.

  What would be the best initial test to do in this patient?

  A. spot fecal fat collection
  B. 72-hour fecal fat collection
  C. CT scan of the abdomen
  D. ERCP
  E. upper endoscopy
  C. CT scan of the abdomen

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  Explanation

  The patient's history and examination are worrisome for pancreatic disease, and he has strong signs of pancreatic insufficiency. His long history of alcohol use suggests the possibility of chronic pancreatitis or pancreatic cancer. Fecal fat studies would only confirm or quantify his steatorrhea. ACT scan would image the pancreas for changes consistent with chronic pancreatitis (duct dilation, calcifications, pseudocysts) and could look for a neoplasm of the pancreas as well. ERCP is not indicated as a first- line test in patients with abdominal pain given its risk of causing acute pancreatitis. Upper endoscopy would be helpful to rule out peptic ulcer disease and other gastric complaints, but would not provide more global information about the abdomen.

  The patient has greasy stools and weight loss, findings seen in patients with steatorrhea due to chronic pancreatitis.

  Patients with steatorrhea malabsorb fat-soluble vitamins (vitamins A, D, E, and K). "Night blindness" (poor night vision) due to vitamin Adeficiency is common among patients with advanced chronic pancreatitis and likely led to this patient's motor vehicle accident. The patient has DM as a consequence of pancreatic endocrine insufficiency, another feature of chronic pancreatitis. Diabetes develops when greater than 80- 90% of the gland has been destroyed. Patients with chronic pancreatitis have a coexisting loss of glucagon from islet cells and, thus, often become brittle diabetics, with hypoglycemia seen after insulin administration. Vitamin K and B12 deficiency, which the patient may have, do not cause hypoglycemia. The patient was previously noted to eat well, so inadequate oral intake is unlikely. Diabetic education should decrease the rate of chronic insulin overdosage.

  The patient has pancreatic exocrine insufficiency and thus cannot produce enough pancreatic enzymes to digest his food. Pancreatic enzyme replacement therapy in tablet form is a mainstay of therapy for chronic pancreatitis. It can rapidly reverse this problem by providing exogenously produced pancreatic enzymes to break down fats, carbohydrates, and proteins for absorption in the small bowel. The patient would not benefit from additional oral feedings without enzyme supplementation and would only worsen his steatorrhea by doing so. He can take food orally, so feeding via gastrostomy, TPN, or PPN are not indicated. The patient's worsening pain and weight loss despite therapy is worrisome for the development of pancreatic cancer. CA-19-9 is frequently (but not universally) elevated in pancreatic cancers, although it can be elevated in cholangiocarcinoma as well. PSA is associated with prostate cancer. CEA is associated with colon cancer. CA-125 is associated with ovarian cancer. AFP is associated with hepatocellular carcinoma.

• Question 704:

  A 52-year-old male construction worker is seen in the emergency department (ED) at a local hospital with complaints of persistent cough for the past 4 months. He has been relatively healthy until a few months ago, when he lost his mother and developed severe depression which left him socially and professionally paralyzed. He has stopped doing any exercise or outdoor activity and spends most of his time at home eating, sleeping, and watching TV. In addition, he has noticed a 20-lb weight gain over this period but attributes it to his lack of exercise and increased food intake. His cough is worse at night, or any time when he lies down to sleep, and he notices a burning sensation in his throat associated with it. It is not associated with fever or chills, and his wife complains that he is constantly clearing his throat after meals. He smoked a few cigarettes per day as a young man in the Navy but quit more than 30 years ago. He denies recent travel or incarceration and has no recollection of any sick contacts. On examination, he is afebrile and appears mildly obese. His lung examination is clear. His oropharynx is red and mucosal membranes are dry and not inflamed.

  Which of the following statements describes the likely cause of his chronic cough?

  A. The patient likely suffers from a common cold due to a viral infection and will improve with symptomatic medications.
  B. The patient most likely suffers from chronic bronchitis exacerbated by a bacterial infection.
  C. The patient has developed gastroesophageal reflux disease (GERD).
  D. The patient has a "nervous" cough due to severe depression.
  C. The patient has developed gastroesophageal reflux disease (GERD).

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  Explanation

  Although the most common cause of chronic cough in adults is the postnasal drip syndrome (not a choice in this question), the patient's cough is present only in the recumbent position and at night. This sign, as well as the fact that he has recently gained considerable amount of weight, point toward the correct diagnosis of GERD. All of the other answers are also potential causes of chronic cough among adults. The history and examination give some clues that point toward GERD (constant clearing of the throat, worse during recumbence, normal nasal mucosa, and worse after meals) and give some others that would make the alternative diagnoses less likely. While 4 months period is too long for a common cold, other infectious agents (including TB) are not likely given the lack of risk factors. It would be unusual for a patient to develop asthma at this age without other symptoms, and chronic bronchitis is even less likely given the remote history of smoking only a few cigarettes per day. Although nervous cough is also possible, this occurs more often as an escape from socially awkward situations or as a stress relieving method. Because the symptoms are due to GERD, they should be treated with a PPI as initial therapy. Although weight loss and exercise may be beneficial in relieving GERD symptoms, they should be considered additional therapies and not curative. Antibiotics are not necessary since the patient does not show signs or symptoms of bacterial or fungal infection. The use of cough suppressants and expectorants would temporarily improve the cough but would do nothing to address the underlying disorder. Inhaled bronchodilators such as beta-2 agonist play no role in the treatment of GERD, unless the patient was to develop pneumonitis and dyspnea.

• Question 705:

  You are following up in your office with a patient who had a magnetic resonance imaging (MRI) of his head for evaluation of persistent headaches. The MRI report reveals a mass suspicious for malignancy. While explaining the need for ongoing testing to determine the etiology, the patient's spouse asks you, "What is the most common tumor in the brain?" Which of the following would be the correct response to this question?

  A. glioblastoma multiforme
  B. metastatic tumors
  C. meduloblastoma
  D. oligodendroglioma
  E. ependymoma
  B. metastatic tumors

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  Explanation

  Metastatic tumors reach the intracranial compartment through the blood stream, generally in patients with advanced cancer. Tumors of different organs vary in their incidences of intracranial metastasis. For example, a patient with disseminated melanoma has a greater than 50% likelihood of acquiring intracranial metastasis, whereas the incidences of such metastasis in carcinoma of the breast and lungs is 35%. Certain carcinomas such as those of the prostate, liver, and adrenals and sarcomas of all types rarely establish intracranial metastasis. A metastasis contrast with the primary glioma in its discrete appearance, globoid shape, and prominent halo of edema

• Question 706:

  Which of the following are currently recommended for all children for every well-child visit?

  A. serum lead levels
  B. hematocrit
  C. PPD
  D. full physical examination
  E. urinalysis
  D. full physical examination

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  Explanation

  While all of the screenings listed may be appropriate for children with varying symptoms, only a full physical examination is recommended by the American Academy of Pediatrics for ALL well-child visits.

• Question 707:

  A 48-year-old male truck driver presents for evaluation of bright red rectal bleeding with bowel movements. He also has the feeling that something protrudes through his anus while he strains to move his bowels but that it withdraws into the bowel when he relaxes. He has no abdominal pain, weight loss, or other symptoms. A colonoscopy reveals no polyps or tumors but does note internal hemorrhoids. Which of the following is the best initial treatment for him?

  A. high fiber diet, frequent sitz baths, and topical steroid ointment
  B. rubber band ligation
  C. sclerotherapy injection
  D. infrared coagulation
  E. surgical hemorrhoidectomy
  A. high fiber diet, frequent sitz baths, and topical steroid ointment

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  Explanation

  Internal hemorrhoids are highly vascularized submucosal cushions located in the anal canal. They are classified as first degree if no prolapse is present; second degree if prolapse occurs with spontaneous reduction; third degree if they require manual reduction; and fourth degree if they are irreducible. Treatment is based on the symptoms and degree of prolapse. Nearly all patients with first- and seconddegree hemorrhoids should initially be placed on a trial of conservative measures including a bowel management program with high fiber diet to avoid straining and constipation, frequent warm baths, and an anti- inflammatory topical cream. If symptoms continue, both rubber band ligation (a small rubber band is placed at the neck of the hemorrhoid resulting in eventual death and detachment of tissue) and infrared coagulation (controlled burn of the vessels at the neck of the hemorrhoid) are good alternatives to surgical therapy. For refractory first- and second-degree hemorrhoids, most third-degree and all fourth-degree hemorrhoids, surgical

• Question 708:

  A 16-year-old nulligravid high school student is on your afternoon office schedule for a "talk visit." She was seen last year by one of your colleagues for an initial GYN evaluation. She is healthy and has no medical problems. Today she tells you that she and her new boyfriend had intercourse the night before, and the condom they were using broke.

  The patient requests a prescription for "Plan B" emergency contraception. You tell her which of the following?

  A. The medication is not effective after 24 hours.
  B. Your office does not dispense prescriptions as such to minors.
  C. She should first seek permission from her parents.
  D. The first dose must be taken within72 hours of intercourse.
  E. The medication will cause an abortion.
  D. The first dose must be taken within72 hours of intercourse.

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  Explanation

  Discussing the potential implications of her sexual activity is warranted, both in terms of potential pregnancy and risk of acquiring sexually transmitted infections. Making assumptions about her decision making (choices B and D) would breach the ethical principles of autonomy and confidentiality. In August 2006, the FDA approved emergency oral contraception (Plan B) to be available over the counter for women ages 18 and older. Younger women must have a prescription from a health care provider. Plan B contains 0.75 mg of levonorgestrel in two doses taken 12 hours apart. It is to be used within 72 hours of unprotected intercourse. The mechanisms of action include delay in ovulation, insufficient corpus luteum function, and interference with sperm transport. It is not an abortifacient. A physician is not obligated to provide treatments which conflict with his or her own personal belief system. Nonetheless, using ethical principles of autonomy, beneficience, nonmaleficence, veracity, and justice, physicians should discuss patients' requests for treatments in an attempt to reach common ground. If that is not possible, the physician should provide an alternative resource to address a patient's request.

• Question 709:

  In your role as a physician in a community health center, you agree to perform sports preparticipation examinations on students from the local high school. You have several scheduled for today. Your first appointment is with a 16-year-old male who is planning to run on the cross-country team in the Fall and play baseball in the Spring. He reports that one time he "blacked out" while running, but he has never had chest pain while exercising and he is one of the top runners on the team. He has no known medical history, denies alcohol, tobacco, recreational drug, or performance-enhancing drug use. He has a cousin who died at the age of 21 of "some kind of heart disease," although your patient is not sure of any details. On examination, he is healthy appearing and has normal vital signs, with a pulse rate of 72 and a blood pressure of 100/65. Auscultation of his heart reveals no cardiac murmur while he is lying down, a soft systolic murmur when he stands which increases on having the patient perform a Valsalva maneuver. The remainder of his examination is normal Your last patient of the day is a 16-year-old male who plans to play on the football team. He has no complaints today, no significant medical history, and no concerning family history. He denies the use of tobacco, alcohol, or any kinds of drugs. His physical examination is entirely normal. Review of his vaccinations reveals that he had a Td vaccination 3 years ago, a varicella vaccination at age 17 months, and 2 MMR vaccinations at age 17 months and 5 years. Appropriate management at this time would include which of the following?

  A. MMR vaccine
  B. Td vaccine
  C. varicella vaccine
  D. screening ECG
  E. urinalysis
  C. varicella vaccine

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  Explanation

  Explanations:

  Primary care physicians are frequently called on to perform preparticipation examinations on young athletes. These types of encounters can be used to serve a number of purposes, including attempting to identify conditions that may adversely affect the athlete during participation, identify conditions that may predispose the athlete to injury, provide anticipatory guidance on high-risk behaviors common to the age group being addressed, and fulfill legal conditions of the institution involved. Fortunately, the rate of sudden death in young athletes is low.

  In those under the age of 35, the most common cause of sudden death is congenital cardiac anomalies. Hypertrophic cardiomyopathy (HCM) is responsible for about onethird of these deaths. Unfortunately, sudden death may be the presenting symptom of HCM. Apersonal or family history of congenital heart disease, symptoms of chest pain or tightness, palpitations, dyspnea, syncope or near-syncope are important. A family history of HCM or unexplained sudden death in someone under the age of 50 is significant as well. The murmur of HCM may not be present in all persons with this disorder.

  To identify the murmur, dynamic auscultation is often necessary. The heart should be auscultated while the patient is lying and then standing. As this murmur is accentuated by maneuvers which reduce cardiac preload, the murmur will get louder when the patient stands or performs a Valsalva maneuver and will diminish as the patient lies or squats. As the patient has the concerning historical point of exertional syncope and a family history of an unexplained, early death along with a characteristic murmur on examination, further evaluation is warranted. In the 26th Bethesda Conference report, the American College of Cardiology recommends that persons with HCM should be restricted from all, except possibly for the least strenuous, athletic activity. In this case, restriction of all athletic activity until the patient can be further evaluated by a cardiologist--preferably one with experience in dealing with the evaluation of athletes--would be the most appropriate option of the choices given.

  Marfan syndrome is a connective tissue disorder that typically affects the eyes, skeletal system, and cardiovascular system. Persons with Marfan syndrome are typically tall and have arm spans that are greater than their height. Signs include long, slender digits, high-arched palates, and pectus deformities of the chest. Lens dislocations in the eye are common. Detecting Marfan syndrome during a preparticipation examination is important because of the occurrence of aortic\ root dilation and the risk of sudden death caused by aortic rupture. The patient in questions 23 and 24 has multiple signs of Marfan syndrome and further evaluation would be indicated. Of the options given, an echocardiogram to evaluate the aortic root and to look for other valvular abnormalities would be indicated. These persons usually require referral to an ophthalmologist as well for a dilated eye examination to evaluate for lens dislocations. Turner syndrome is a syndrome of gonadal dysgenesis, associated with a 45, X karyotype (or another defect of the X chromosome). This syndrome is typically associated with a short stature and multiple anomalies including a webbed neck and "shield" chest. The female athlete triad is a syndrome of disordered eating, amenorrhea, and osteoporosis. It is seen most often in participants in activities that emphasize low body weights, such as gymnastics or ballet. The presence of regular menstrual cycles makes this diagnosis unlikely. Atlantoaxial instability can be associated with Down syndrome.

  Physicians performing preparticipation examinations on someone with Down syndrome must consider performing lateral cervical spine x-rays with flexion and extension views. This patient does not have any of the classic findings of Down syndrome. Similarly, she does not exhibit any of the classic symptoms of type 1 diabetes polydipsia, polyphagia, and polyuria. Performing serum glucose testing would therefore not be indicated. The patient is the most typical type of patient who presents for a preparticipation examination-- the healthy adolescent. This may be the only encounter that a physician will have with an adolescent, especially an adolescent male. It is in this population where a physician can use this encounter to address other age appropriate health maintenance issues. As the patient had a Td booster 3 years ago, another one at this point would not be indicated (although consideration could be given to providing a Tdap). Other vaccinations to consider would be hepatitis B and MMR, if he has not previously been adequately immunized. As he has had two MMR vaccines, he has completed the recommended series. There is no history given regarding hepatitis B vaccination and this would be something to address clinically. A nonjudgmental discussion of sexual behaviors, drug use, alcohol use, and other high-risk behaviors would also be appropriate. Screening athletes who have neither concerning symptoms nor signs with ECGs is not recommended because of the poor predictive values and significant costs involved with mass screening. ECGs should be performed without hesitation in any athlete who has a history, examination finding, or preexisting diagnosis of a potentially high-risk condition. Although some localities may require a urinalysis as part of a preparticipation examination, there is no evidence to recommend universal screening

• Question 710:

  A 42-year-old man presents to your clinic with a 1-week history of pain and inflammation involving his right first metatarsophalangeal (MTP) joint. He describes the pain as sudden in onset and worse at night. He denies experiencing any fever or traumatic injury to the joint and states that he has never had this type of pain before. He denies any chronic medical conditions, any prior surgery, and any current medication use. Besides an erythematous and exquisitely tender right first MTP joint, the remainder of his physical examination is unremarkable.

  Which of the following is true of the patient's condition?

  A. It commonly presents in premenopausal women.
  B. It commonly presents as a monoarticular arthritis.
  C. Episodes of pain and inflammation become more frequent but resolve more quickly as the disease progresses.
  D. The presence of tophi is a common early finding.
  E. A blood test is the diagnostic gold standard.
  B. It commonly presents as a monoarticular arthritis.

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  Explanation

  This patient's presentation is consistent with gout. Aspiration of his first MTP joint is likely to reveal the presence of needle-shaped, negatively birefringent crystals. Rhomboid-shaped, positively birefringent crystals are characteristic of calcium pyrophosphate deposition disease, or pseudogout, with the knee being the joint most commonly affected. Nonbirefringent crystals are found in hydroxyapatite crystal deposition disease. The synovial fluid from joints affected by gout typically show evidence of inflammation in the form of leukocytosis with a predominance of polymorphonuclear neutrophils. The presence of bacteria in synovial fluid is characteristic of infection rather than gout, although gout and infectious arthritis may coexist. (Cecil Textbook of Medicine, pp. 17031708) Acute gouty arthritis usually presents in a monoarticular or oligoarticular distribution, with the first MTP joint most commonly affected. The diagnostic gold standard is detection of urate crystals within the synovial fluid of affected joints.

  It most commonly affects adult men with a peak incidence in the fifth decade of life. While patients with gout typically also have hyperuricemia, only a small fraction of the people with hyperuricemia actually have or will develop gout.

  Tophi are primarily seen in patients with long-standing hyperuricemia and is considered a finding of chronic gouty arthritis. As the disease progresses, acute attacks become more frequent and last longer if left untreated. Indomethacin inhibits the prostaglandin synthesis that facilitates the inflammation of acute gout and inhibits the phagocytosis of urate crystals by leukocytes. This inhibits the cell lysis and release of cytotoxic factors that initiate the inflammatory cascade. Allopurinol (an inhibitor of urate synthesis) and probenecid and sulfinpyrazone (promoters of urate excretion) are useful for preventing gout but are not effective during an acute gout attack. Aspirin is inappropriate in the treatment of gout since it can inhibit urate elimination and, therefore, increase hyperuricemia.