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

USMLE USMLE-STEP-2 Online Questions & Answers

• Question 211:

  A46-year-old attorney is noted to have normal cholesterol levels but a very high fasting triglyceride level of 1600. He is otherwise healthy and has no risk factors for CAD. Which of the following statements is correct?

  A. Hypertriglyceridemia is a strong independent risk factor for premature CAD.
  B. Dietary modification is usually sufficient.
  C. High triglyceride levels are associated with elevated high-density lipoprotein (HDL) levels.
  D. Hypertriglyceridemia is usually associated with skin lesions.
  E. Control of triglyceride levels can prevent attacks of acute pancreatitis in patients with extreme hypertriglyceridemia.
  E. Control of triglyceride levels can prevent attacks of acute pancreatitis in patients with extreme hypertriglyceridemia.

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  Explanation

  Hypertriglyceridemia has not been shown to be a strong independent risk factor for CAD, however, epidemiologic data do suggest a relationship. According to the National Cholesterol Education Program, when tirglycerides are above 200 mg/dL then non-HDL (total HDL) cholesterol becomes a pharmacologic treatment target. Severely elevated triglycerides (1000 mg/dL) are a recognized risk factor for attacks of acute pancreatitis, and control of the triglycerides can prevent these attacks. Diet alone is usually not sufficient at these high levels. A National Institutes of Health Consensus Conference has recommended that treatment be initiated in all patients with triglycerides greater than 500 mg/ 100 mL to prevent acute pancreatitis. Skin lesions are not present with hypertriglyceridemia.

• Question 212:

  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 likely diagnosis?

  A. torsion of the right testicle
  B. pyelonephritis
  C. appendicitis
  D. right ureteral calculus
  E. acute urinary retention
  D. right ureteral calculus

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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 213:

  A 40-year-old woman with no previous psychiatric history seeks help from her internist for a sleep problem. Initially, she is able to fall asleep but then sleeps fitfully, and finally around 4:00 a.m. decides to stay up. She averages approximately 34 hours of sleep per night, and this has been occurring for the last 3 weeks. She finds herself quite tired and "blue" during the day but is unable to nap. Mornings are "the worst" for her, but she feels better toward the end of the day. There has been a 15-lb weight loss because "I'm just not hungry." She denies any physical problems except for constipation. As a gradeschool teacher, she feels extremely stressed but sees no way out and no way to improve the situation. At times, suicide seems like a possible option, and she admits to spending long hours brooding on how to do it. A physical examination is unremarkable.

  Which of the following is the most likely diagnosis?

  A. borderline personality disorder
  B. major depression
  C. dysthymia
  D. Alzheimer's disease
  E. generalized anxiety disorder
  B. major depression

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  Explanation

  This woman's symptoms meet the criteria for a major depressive episode. She has had a depressed (blue) mood for at least a 2-week period, a significant weight loss, insomnia, fatigue and loss of energy, and thoughts of suicide. Because her symptoms seem to be limited to 3 weeks, dysthymic disorder would most likely not be considered. There are no indications for an organic mental disorder that would suggest Alzheimer's disease. Generalized anxiety disorder is characterized by excessive anxiety and worry for about 6 months. For a diagnosis of borderline personality disorder, patterns of instability in relationships, selfimage, affect, and impulsivity would have been present in early adulthood. None of that is described here.

• Question 214:

  A 14-year-old boy complains of breast enlargement on the left side. He denies pain, discharge, or any drug use. He is on no medications and is otherwise healthy. On physical examination, his sexual maturity rating (Tanner) is stage II for both genitalia and pubic hair growth. Initial management should include which of the following?

  A. magnetic resonance imaging of the head
  B. urine drug screen for marijuana
  C. chromosome analysis
  D. reassurance that this is a normal condition
  E. ultrasound imaging of the abdomen and testes
  D. reassurance that this is a normal condition

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  Explanation

  Gynecomastia is the enlargement of male breast tissue and occurs in approximately onethird of adolescent males during early- to midpuberty. It usually resolves spontaneously and requires no further evaluation beyond a careful history and physical examination. Features include: breast tissue <4 cm in diameter and resembling female breast budding, and pubertal development between Tanner stage II and IV. Pubertal development signs precede gynecomastia by at least 6 months. It may be more noticeable in obese boys. A drug and medication history should be obtained; these include estrogens, androgens, human chorionic gonadotropin (hCG), cardiovascular drugs (reserpine, methyldopa, digitalis), cytotoxic agents (busulfan, vincristine), antituberculosis drugs (INH), psychoactive drugs (tricyclic antidepressants, diazepam), ketoconazole, spironolactone, cimetidine, and phenytoin. Illegal drugs include marijuana, heroin, methadone, amphetamines, as well as alcohol. If there is evidence of precocious puberty, hypogonadism or macrogynecomastia (breast tissue >5 cm diameter), laboratory testing should be done including dehydroepiandrosterone sulfate (DHAS), FSH, and LH, hCG, estradiol, and testosterone. Thyroid- stimulating hormone (TSH) may be obtained to rule out hyperthyroidism. Boys with Klinefelter syndrome have hypogonadism (testes <3 cm in diameter), delayed pubertal development, and gynecomastia. Laboratory tests reveal increased FSH and LH, and decreased testosterone; the diagnosis is confirmed by chromosome analysis. If DHAS, hCG, or estradiol levels are increased, an MRI of the head to exclude a CNS tumor and ultrasound of abdomen and testes to rule out an adrenal, liver, or testicular tumor should be considered.

• Question 215:

  It is 2007. You are planning allocation of health department resources to meet the needs of a typical

  A. S. community over the next 10 years. You decide to allocate funding for each opulation group based on anticipated percent of population growth in each age group.The largest proportional increase in funding will go toward which age group?
  B. 0- through 10-year olds
  C. 15- through 34-year olds
  D. 35- through 45-year olds
  E. 65- through 74-year olds
  F. those 75 years of age and older
  E. 65- through 74-year olds

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  Explanation

  Data from the National Center for Health Statistics indicate that the older age groups will continue to grow more rapidly than the total population. The population age 6574 years will increase from 6 to 10% of the total population between 2005 and 2030. The proportion of the population age 75 years and older is growing at the fastest rate and by 2040 this group will exceed the population 6574 years of age. Disability and quality-of-life issues are very important for this age group.

• Question 216:

  Apreviously healthy 45-year-old man presents with a 9-month history of a slow-growing, painless right neck mass. He is a nonsmoker and has no significant past medical history. On examination, there is a nontender, discrete, 3-cm mass over the angle of the right mandible. Facial muscle function and sensation are normal. An oropharyngeal examination is normal. Which of the following is the most likely diagnosis?

  A. metastatic carcinoma
  B. infectious parotitis
  C. pleomorphic adenoma of the parotid
  D. Hodgkin's disease
  E. reactive cervical lymphatic hyperplasia
  C. pleomorphic adenoma of the parotid

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  Explanation

  The anatomic location of the mass suggests a parotid origin, and the lengthy history and absence of symptoms and signs of inflammation are consistent with a neoplasm of the parotid. The most common salivary gland neoplasm is a benign pleomorphic adenoma. Metastatic carcinoma from a head and neck primary tumor may first present as a neck mass, usually along the anterior or posterior cervical lymph node chain, and often in a patient with such risk factors as a history of smoking. Infectious parotitis may occur in the elderly or diabetic patient, usually presenting with a shorter history, with symptoms and signs of inflammation. Hodgkin's disease can present as a painless neck mass involving the anterior or supraclavicular lymph nodes. Reactive cervical lymphatic hyperplasia is associated with an inflammatory or infectious focus in the head and neck. The optimal management for a pleomorphic adenoma in the lateral lobe of the parotid is a superficial parotidectomy. IV antibiotics are not indicated in the absence of an inflammatory or infectious process. Although an excisional biopsy may be indicated for a mass arising from cervical lymph nodes, enucleation of a neoplastic parotid mass is insufficient and associated with an increased incidence of local recurrence. Observation and re- evaluation are inappropriate in this patient. Achest x-ray would be indicated in the evaluation of a patient with suspected Hodgkin's disease.

• Question 217:

  A 16-year-old girl presents because she has not begun to menstruate. Also, breast development and pubic hair have not developed. She is 59 in. (150 cm) tall and weighs 115 lbs (52 kg). On examination, her vital signs are normal. She has skin folds on the lateral sides of her neck. She has evidence of cubitus valgus. Breasts are Tanner stage 1 and the nipples appear to be spaced wider than average. Pubic hair is Tanner stage 1. The external genitalia are normal. The vagina is of normal depth and a small cervix is seen on speculum examination. The uterus is present but small. There are no adnexal masses.

  What is the most likely karyotype of this 16 year old?

  A. 46,XX
  B. 46,XY
  C. 45,X
  D. 47,XX trisomy 21
  E. 47,XXY
  C. 45,X

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  Explanation

  The short stature and other features of Turner syndrome are strong presumptive evidence of a 45,X karyotype. A46,XX and a 46,XY karyotype may be found in women with gonadal dysgenesis. Their clinical presentation is absence of pubertal events, but lack of the physical features of Turner syndrome. Most helpful in excluding either of these karyotypes is the short stature: those with 46,XX or 46,XY gonadal dysgenesis are of normal height. There is nothing in the clinical presentation to suggest 47,XX trisomy 21. The phenotype of those with a 47,XXY karyotype is male, Klinefelter syndrome.

• Question 218:

  Of the following, which is considered a cortical dementia?

  A. Huntington's disease
  B. Pick's disease
  C. Parkinson's disease
  D. occult hydrocephalus (normal pressure)
  E. none of the above
  B. Pick's disease

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  Explanation

  Pick's disease is considered a cortical dementia, with the preponderance of pathologic findings found in the frontotemporal area. Aphasia, apraxia, and agnosia are signs sometimes seen in these patients. Huntington's and Parkinson's diseases are caused by pathologic changes in the basal ganglia. Pathologic changes are seen in the ventricles in occult hydrocephalus. Signs seen in subcortical dementia more characteristically involve motor disorders: rigidity, tics, gait difficulties, and incoordination.

• Question 219:

  A baby is born to a mother who is positive for hepatitis B surface antigen (HBsAg). Your plan is to do which of the following?

  A. Give the infant a hepatitis B immunization.
  B. Give the infant hepatitis B immune globulin (HBIG).
  C. Give the infant a hepatitis B immunization and HBIG.
  D. Obtain liver function tests and hepatitis serology of the infant.
  E. Give the HBIG only if the child is positive for HBsAg.
  C. Give the infant a hepatitis B immunization and HBIG.

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  Explanation

  Transmission of perinatal hepatitis B virus (HBV) infection can be prevented in 95% of infants born to HBsAg-positive mothers by early active (immunization) and passive immunoprophylaxis (HBIG), preferably within 12 hours of life. The immunization series should be completed by 6 months of life. The child should have serology testing 13 months after completion of the series. Testing for anti-HBs will establish if additional vaccine doses are needed; testing for HBsAg will identify infants who are chronically infected. Mothers whose HBsAg status is unknown should be tested as soon as possible; the first vaccine dose should be given within 12 hours of birth. If the woman is found to be positive, HBIG should be given as soon as possible, not later than 7 days of age.

• Question 220:

  Select the appropriate incubation period of the Infectious mononucleosis infectious disease of childhood.

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