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

USMLE USMLE-STEP-2 Online Questions & Answers

• Question 491:

  A7-month-old baby presents with a history of constipation for 1 month. He has one hard stool every week. He has been well otherwise. His physical examination is normal. Which of the following is the most likely cause of his problem?

  A. hypothyroidism
  B. lead poisoning
  C. functional constipation
  D. Hirschsprung disease
  E. hypocalcemia
  C. functional constipation

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  Explanation

  Hypocalcemia is not a cause of constipation. On the contrary, it increases irritability of nerve cells and may result in diarrhea. Hypothyroidism, lead poisoning, and Hirschsprung disease all may be associated with constipation. Congenital hypothyroidism and Hirschsprung disease (a congenital disorder characterized by regional absence of ganglion cells from the myenteric plexus of the colon) present at birth. Lead poisoning is more common after the child becomes mobile. Functional constipation is the most common cause of constipation at this age. It is usually due to dietary factors.

• Question 492:

  A 28-year-old man with a past history of bilateral orchiopexy for cryptorchidism presents with a painless, unilateral right scrotal enlargement. On examination, there is a palpable right testicular mass and enlarged inguinal nodes. Scrotal ultrasonography demonstrates heterogeneity of the testis, with an associated hydrocele. A CT scan of the abdomen and pelvis demonstrated right-sided retroperitoneal adenopathy. CT scan of the chest is normal.

  Staging workup and surgery reveal a seminoma of the testicle, with positive inguinal and retroperitoneal nodes. Therapeutic management for this patient is which of the following?

  A. external beam radiotherapy
  B. multidrug combination chemotherapy
  C. combination radiotherapy and multidrug chemotherapy
  D. clinical surveillance
  E. laparotomy with pelvic and retroperitoneal node dissection
  C. combination radiotherapy and multidrug chemotherapy

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  Explanation

  Cryptorchidism increases the risk of developing a testicular malignancy. This patient has a solid testicular mass which should be presumed to be secondary to a testicular malignancy. Optimal surgical management is inguinal exploration, control of the spermatic cord, biopsy of the mass, and radical orchiectomy with high ligation of the cord, if tumor is confirmed. Transscrotal aspiration, exploration, or needle biopsy is contraindicated because of risk of tumor spillage, and risk of altering the lymphatic drainage of the scrotum. Laparotomy and retroperitoneal node dissection is not indicated until after confirmation of the diagnosis and excision of the primary tumor. This patient has seminoma with disease spread to ipsilateral regional lymph nodes

• Question 493:

  A70-year-old woman was brought to the emergency department following her involvement in a minor car accident. She had sustained no injuries but was very upset and was, therefore, referred to a psychiatrist. After speaking at length about her part in the accident and sharing her reactions, she still remained tremulous, anxious, and tearful. She has no history of addiction. You decide to use an anxiolytic to help her.

  Which of the following is the best choice?

  A. diazepam
  B. clorazepate
  C. lorazepam
  D. buspirone
  E. temazepam
  C. lorazepam

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  Explanation

  Lorazepam, because of its relatively short half-life, intermediate rate of onset, and absence of active metabolites, would be an appropriate medication for this elderly woman. Diazepam and clorazepate both have long half-lives as well as active metabolites. These properties lead to more severe side effects in older patients, such as prolonged sedation, respiratory depression, confusional states, and disorientation. Temazepam, although it has no active metabolites and a relatively short halflife, is very sedating and is used to promote sleep. Buspirone, a nonbenzodiazepine, is an effective antianxiety agent, but it may take up to a week to exert its effect. The woman in this case needs medication that will help her quickly

• Question 494:

  A young woman who works full time doing manual work in a factory, but who also has secretarial skills, is making her first prenatal visit to your office. Her work involves climbing high ladders, with the risk of falling.

  Which of the following is the best recommendation regarding this patient's job?

  A. Advise the patient not to work.
  B. Recommend that the patient seek alternative work.
  C. Recommend no change in employment but suggest avoiding risk.
  D. Suggest that you provide her with a restriction stating that she is not to work at unprotected heights.
  E. Write a note to the employer requesting reassignment of the patient to a secretarial position.
  B. Recommend that the patient seek alternative work.

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  Explanation

  The situation described in the question calls for clinical judgment. Restrictions should be specific and should pertain to what the patient may actually be asked to do. A company may not interdict a woman from performing a job just because she is pregnant. You should offer your best advice to a pregnant woman concerning her health and the health of the fetus. Advice should be given to patients and not to their employers. The vast majority of women can continue to do their jobs without restrictions. Telling a patient to simply avoid risk is impractical, difficult to interpret, and cannot be applied effectively. Advise and offer to write task-specific restrictions, such as, "not to climb ladders and not to lift, push, or pull with more than 20 lbs of force," or "not to work at unprotected heights such as on high ladders." The patient is well advised to discuss her needs with her employer. The physician should not communicate directly with the employer unless that is requested by the patient.

• Question 495:

  An HMO has its annual medical directors, meeting, and new treatments are discussed. A recent study has just clearly demonstrated that a new drug can lower blood pressure significantly, although monitoring tests for renal function are required. The directors consider adding the treatment to their list of approved treatments but feel handicapped. Which of the following is one of the real disadvantages of making treatment decisions based on clinical outcomes alone?

  A. Clinical tests cannot reliably tell which treatment works best.
  B. Clinical trials ignore the difference in costs between treatments.
  C. Results of clinical trials cannot possibly be applied to real-world situations.
  D. Effects noted in the study population will not show up in the general population.
  E. The advantages of improvement in clinical outcomes are always too significant to ignore.
  B. Clinical trials ignore the difference in costs between treatments.

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  Explanation

  Although clinical trials can determine which treatment works best, they cannot determine the cost of this success. Unfortunately, they do not take into account costs and ultimate benefits, which would be the role of a costbenefit study. If properly constructed, with study and control groups randomly drawn from the general population, the results should be applicable to the general population. In addition, they usually determine what works best by measurement of a clinical endpoint. In many cases, the treatment may achieve its objective, but the change in parameters may not be significant. It is worthy of note that the USPSTF is now taking cost-effectiveness into account when making recommendations.

• Question 496:

  A32-year-old woman reports that she has been in a low-grade, chronically depressed mood for more days than not for the past 3 years. She reports that she has never had a period of severely depressed mood, but the low-grade feeling of sadness has not gone away for more than 2 or 3 days at a time over the past 3 years. Identify the diagnosis below that best describes the situation.

  A. major depressive disorder, recurrent
  B. bipolar I disorder
  C. bipolar II disorder
  D. cyclothymia
  E. dysthymic disorder
  F. mood disorder due to a general medical condition
  G. substance-induced mood disorder
  E. dysthymic disorder

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  Explanation

  The criteria for mood disorders depend on the presence or absence and duration of depressive and hypomanic or manic symptoms as well as on their severity, and also on the presence or absence of a causative general medical condition or the ingestion of substances. Major depressive disorder, recurrent, is marked by the lifetime occurrence of two or more major depressive episodes without intervening hypomanic or manic episodes. A major depressive episode is a severe depression which has lasted at least 2 weeks. Bipolar I disorder is characterized by a history of at least one full-blown manic episode, during which the patient's mood has been abnormally and persistently elevated, expansive or irritable for at least 1 week with marked impairment in occupational functioning. Bipolar II disorder, on the other hand, is marked by a history of at least one major depressive episode and at least one hypomanic episode, during which a patient's mood has been elevated, but not to the extent of causing marked impairment in social or occupational functioning. Apatient with bipolar II disorder may not, by definition, have had a full- blown manic episode.

  Cyclothymia is marked by periods of hypomanic symptoms alternating with depressive symptoms that do not meet the criteria for a major depressive episode. Dysthymic disorder is marked by a persistent, low- grade depression occurring more days than not for at least 2 years. Amood disorder due to a general medical condition is a prominent and persistent disturbance in mood that is judged to be the direct physiologic effect of a general medical condition, such as hyperthyroidism. A substance-induced mood disorder is a prominent and persistent disturbance in mood that is judged to be due to the direct effects of a substance, but which continues beyond the usual period of intoxication or withdrawal from a substance.

• Question 497:

  A40-year-old previously healthy man presents with sudden onset of severe abdominal pain that radiates from the right loin (flank) to groin. This pain is associated with nausea, sweating, and urinary urgency. He is distressed and restless, but an abdominal examination is normal. Which of the following is the most appropriate next step in management?

  A. insertion of a urethral catheter
  B. IV fluid hydration, IV analgesics, and nonenhanced computed tomography(CT) scan
  C. IV fluid hydration, IV analgesics, and arrangements for lithotripsy
  D. cystoscopy and retrograde pyelogram
  E. urine culture, followed by initiation of antibiotic therapy
  B. IV fluid hydration, IV analgesics, and nonenhanced computed tomography(CT) scan

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  Explanation

  The clinical signs and symptoms of a ureteral calculus are secondary to sudden obstruction of a hollow viscus, with visceral referred pain from loin to groin. The pain is severe and colicky in nature, with ureteral peristalsis against the obstruction. This is often associated with reflex vomiting mediated by visceral stretch and pain fibers. Typically, the patient is restless and cannot find a position of comfort. Urinary urgency and hematuria are common. Torsion of the testes produces sudden scrotal pain, and may have associated vague lower abdominal pain and vomiting. Pyelonephritis is associated with flank pain and costovertebral angle tenderness that is progressive in severity and constant in nature.

  Appendicitis will present with vague periumbilical pain, migrating to the right lower quadrant with the development of peritonitis. In the latter stages, the patient will lie quietly, as movement exacerbates the pain from peritoneal irritation. By increasing hydration and adequate analgesia, most patients will pass ureteral stones spontaneously. An imaging study should be obtained in all patients presenting with symptoms of urinary calculi. Nonenhanced CT scan will identify the location of the stone, size, and number of stones. This information assists with planning further management options, including referral for lithotripsy or cystoscopy and retrograde ureteroscopy.

• Question 498:

  A39-year-old woman known to have fibrocystic disease of the breast complains of persistent fullness and pain in both breasts. Which of the following drugs will be most effective in relieving her symptoms?

  A. tamoxifen
  B. bromocriptine
  C. medroxyprogesterone acetate
  D. danazol
  E. hydrochlorothiazide
  D. danazol

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  Explanation

  Danazol, in oral doses of 100, 200, or 400 mg daily for 46 months, relieves breast pain and reduces nodularity in 90% of women. The beneficial effects often last for several months after discontinuation of the drug. Tamoxifen is a synthetic antiestrogen that competes with estrogen receptors in the breast. Relief of symptoms symptoms has been achieved in approximately 70% of women in small studies, and seems to be ore effective in women with cyclic rather than continuous pain. Bromocriptine inhibits prolactin secretion, not recognized as a cause of fibrocystic breast disease and mastodynia. Oral progestins (e.g., medroxyprogesterone acetate), depot medroxyprogesterone acetate (Depo Provera), or OCs may provide symptomatic relief, but symptoms usually return after these are stopped. Hydrochlorothiazide provides unpredictable relief of symptoms.

• Question 499:

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

  A. 16 days
  B. 78 days
  C. 810 days
  D. 1021 days
  E. 3050 days
  F. 120180 days
  A. 16 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 500:

  A 44-year-old man presents with fears that his mathematical abilities have been slowly sucked out of his brain for the last 4 years. He believes an "alien force disguised as a human being" is responsible. To avoid contacting this being, he has isolated himself in a room in a boarding house. His wife divorced him and left with their children. After 10 years teaching math at a local high school, he resigned about 3 years ago. He supports himself by "collecting cans." His affect is blunted. His appearance is disheveled, unshaven, and unwashed.

  Which of the following hypotheses is the leading hypothesis to explain the patient's psychotic symptoms?

  A. serotonin hypothesis
  B. biogenic amine hypothesis
  C. acetylcholine hypothesis
  D. dopamine hypothesis
  E. gamma aminobutyric acid (GABA) hypothesis
  D. dopamine hypothesis

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  Explanation

  The dopamine hypothesis of schizophrenia grew from the observations that medications that block dopamine receptors have antipsychotic activity and medications that stimulate dopamine receptors (amphetamines) can induce psychosis. Serotonin abnormalities have been implicated in mood and anxiety disorders. The biogenic amine hypothesis of mood disorders was based on the finding that tricyclic and MAOI drugs are effective in alleviating the symptoms of depression. The GABAergic system has been implicated in anxiety disorders because benzodiazepines which are GABAergic have antianxiety effects. Acetylcholine abnormalities have been associated with dementia.