USMLE USMLE Certifications USMLE-STEP-2 Questions & Answers

• Question 1:

  A 65-year-old man presents to the physician's office for his yearly examination. His past history is pertinent for a 40 pack-year smoking history and colon cancer 3 years ago for which he underwent a sigmoid colectomy. The most recent colonoscopic follow-up 3 months ago was negative. His physical examination is normal. Laboratory results show a normal CBC and electrolytes, markedly elevated cholesterol, and a CEA of 12 compared to values of less than 5 obtained every 6 months since colectomy. A repeat CEA 4 weeks later was 15, and liver function tests revealed a minimally elevated alkaline phosphatase, with normal transaminases and bilirubin. In your discussion with the patient regarding the risks and benefits of the different management options listed above, which of the following values should you quote regarding the expected 5-year survival rate following curative surgical resection?

  A. 510%

  B. 1520%

  C. 2535%

  D. 4050%

  E. 6070%

  Correct Answer: C

  In a patient who has undergone surgical resection for colon cancer, elevated CEA, and liver function tests must be followed by an evaluation for metastatic disease, including the possibility of extrahepatic disease. The CT scan is the most useful examination to evaluate both intra- and extrahepatic disease. Various CT scans have been advocated for liver tumors, including dynamic and portography scans. PET scans may detect occult extrahepatic disease and studies are underway to define the role of this modality in metastatic colon cancer. MRI shows promise as a useful examination and can be useful to characterize lesions of uncertain significance. Radionuclide liver scans have been supplanted by more accurate scans. Surgical resection, if possible, is the treatment of choice for metastatic colorectal cancer to the liver. Chemotherapy is reserved for patients who are not surgical candidates or refuse surgical treatment. Radiation therapy is not usually used in these patients. Observation and repeat imaging delays the treatment for patients who may be respectable. The expected 5-year survival has been shown in multiple studies to be greater than 20%, usually in the range of 25 and 35%.

• Question 2:

  A 65-year-old man presents to the physician's office for his yearly physical examination. His only complaint relates to early fatigue while playing golf. Past history is pertinent for mild hypertension. Examination is unremarkable except for trace hematest-positive stool. Blood tests are normal except for a hematocrit of

  32. A UGI series is performed and is normal. A barium enema is performed, and one view is shown in the figure below.

  

  Which of the following is the most likely diagnosis?

  A. diverticular disease

  B. colon cancer

  C. lymphoma

  D. ischemia with stricture

  E. Crohn's colitis with stricture

  Correct Answer: B

  The clinical features of colon cancer are variable depending on the location. On the right, fatigue, as a manifestation of anemia, may be the predominant symptom; whereas, obstructive complaints may predominate for lesions on the left. In the figure, an annular or "apple core" lesion is noted, consistent with carcinoma. Radiography of diverticular disease would show numerous protrusions from the lumen, usually localized to the sigmoid colon. Lymphoma may occur in the colon, but this site of disease is rare, and widespread disease can be documented in most cases. Ischemia usually occurs at the splenic flexure, and the resultant stricture would produce a longer segment of narrowing than that usually seen with carcinoma. Patients with Crohn's disease would manifest symptoms of abdominal pain and diarrhea, and barium x-rays would show thickened bowel wall, mucosal ulcerations, and cobblestone appearance. The treatment of colon cancer in this patient would be surgical resection and anastomosis. Colostomy may be appropriate in selected patients with obstruction in an unstable patient in whom resection is not feasible. Surgical bypass would be appropriate only or palliative therapy of unresectable disease. Radiation therapy or chemotherapy without surgical resection and staging is not recommended.

• Question 3:

  A54-year-old man presents to the emergency department on transfer from another hospital at the request of the family. He was admitted to the outside hospital 2 weeks ago with abdominal pain, nausea, vomiting, and fever. He was treated with antibiotics, NG tube decompression, and TPN without significant improvement. He developed jaundice 2 days ago. His past history is pertinent for a 40 pack- year smoking history, chronic alcohol abuse, and diabetes. Examination reveals a mildly jaundiced patient with vital signs of temperature 100°F, pulse rate 95/min, and BP 110 /60 mmHg. Cardiac examination is unremarkable, lung examination reveals decreased breath sounds at the bases bilaterally, and abdominal examination reveals fullness in the epigastrium with tenderness and voluntary guarding. For above patient with jaundice, select the one most likely diagnosis.

  A. hepatitis A

  B. hemolysis

  C. choledocholithiasis

  D. biliary stricture

  E. choledochal cyst

  F. pancreatic carcinoma

  G. liver metastases

  H. cirrhosis

  I. pancreatitis

  Correct Answer: I

  Pancreatitis may be the cause of jaundice by different mechanisms, resulting in compression of the common bile duct (CBD). Acute pancreatitis may cause edema of the head with resultant compression of the CBD; pancreatitis may lead to a pseudocyst in the head with compression of the duct; and chronic pancreatitis may lead to dense scarring around the duct with a resultant stricture. The clinical scenario of an alcohol abuser with acute abdominal pain; nausea; vomiting; jaundice; and a tender, palpable epigastric mass is most consistent with acute pancreatitis with CBD obstruction attributable to a pseudocyst.

• Question 4:

  A 70-year-old man was admitted to the ICU with severe pancreatitis. During his ICU course, he underwent

  several CT scans with IV contrast and was also treated with an aminoglycoside for a urinary tract infection.

  The patient required a prolonged course of TPN, and developed Candida sepsis treated with amphotericin.

  He subsequently developed polyuria with urine osmolality of 250 mOsm/L and serum osmolality of 350

  mOsm/L. After receiving 5 units of vasopressin intravenously, there is no change in urine osmolality or

  urine output.

  Select the most likely diagnosis for each of the patients with polyuria.

  A. central diabetes insipidus (DI)

  B. nephrogenic DI

  C. water intoxication

  D. solute overload

  E. diabetes mellitus

  Correct Answer: B

  DI is a disorder due to impaired renal conservation of water. DI presents with polyuria and dilute urine in the presence of an elevated serum osmolality. This is either secondary to impaired production of antidiuretic hormone (ADH) from the posterior pituitary (central DI), or refractoriness of the distal renal tubules to ADH (nephrogenic DI). Central DI may complicate closed-head injury, and is considered a poor prognostic sign. These patients will respond to exogenous IV vasopressin, with resultant increase in urine osmolality and decrease in urine volume. Nephrogenic DI may be congenital, familial, or acquired. Acquired nephrogenic DI may occur in the setting of repeated renal tubular insults such as sepsis, IV contrast, and nephrotoxic drug therapy. With administration of vasopressin, these patients will have no change in urine osmolality or urine volume because the renal tubules are unresponsive. DI must be differentiated from other causes of polyuria. Water intoxication results from ingestion of a large volume of fluid, with resultant dilutional hyponatremia. If the patient has a normal diluting capacity, there will be polyuria, with a proportionally low serum and urine osmolality. Prolonged fluid restriction will result in appropriate rise in urine osmolality. Osmotic diuresis may occur from solute overload when the renal tubules are unable to reabsorb adequate quantities of filtered solutes. This is associated with administration of mannitol or, in the presence of glycosuria, from diabetes mellitus.

• Question 5:

  A 5-week-old infant presents with a 1-week history of progressive nonbilious emesis, associated with a 24hour history of decreased urine output. The infant continues to be active and eager to feed. On examination, the infant has a sunken fontanelle and decreased skin turgor. The abdomen is scaphoid, and with a test feed, there is a visible peristaltic wave in the epigastrium. The diagnosis is best confirmed by which of the following?

  A. abdominal ultrasound

  B. careful clinical examination with palpation of an epigastric mass

  C. UGI contrast study

  D. surgical exploration

  E. endoscopy

  Correct Answer: B

  Infants with pyloric stenosis usually present after the third week of life with symptoms of progressive pyloric outlet obstruction secondary to increasing hypertrophy of the pyloric muscle. There are often clinical signs of dehydration, but the infant usually appears well and is eager to feed. Viral gastroenteritis and urinary tract sepsis may be associated with signs of such systemic illness as lethargy, poor feeding, and, in some cases, fever. Gastroesophageal reflux more typically presents with a history of regurgitation since birth. Milk protein allergy is often associated with colicky abdominal pain and diarrhea. The pathognomonic sign on clinical examination is a palpable "olive" in the epigastrium or right upper quadrant. Abdominal ultrasound is operator dependent, but with expertise in interpretation of the study, the thickened elongated pyloric channel can be demonstrated. AUGI contrast study may show the classic "shouldering" of the pyloric muscle, with a "string sign"; this also requires expertise in performing the examination, and other causes of pyloric outlet obstruction, such as pylorospasm may be misinterpreted as a positive study. Surgical exploration should be reserved for those patients in whom the diagnosis has been confirmed and only after the infant has received fluid resuscitation. Infants with gastric outlet obstruction develop a hypochloremic, hypokalemic metabolic alkalosis. This is secondary to the loss of chloride in the gastric contents, and the renal reabsorption of sodium in exchange for potassium and hydrogen. Carbonic anhydrase converts carbonic acid to hydrogen and bicarbonate ions, allowing hydrogen to be excreted in the urine, with retention of the bicarbonate. Hence, with the metabolic alkalosis, there is a "paradoxical aciduria." Hypernatremic, hyperchloremic, hypokalemic metabolic acidosis develops in infants with diarrhea. Infants with gastroesophageal reflux do not usually develop significant electrolyte derangements. Infants with pyloric stenosis will usually require a period offluid resuscitation to correct hypovolemia as well as electrolyte and acid-base abnormalities.

  This is followed by a pyloromyotomy. Infants with vomiting and diarrhea from viral gastroenteritis are often successfully managed with oral rehydration. Prokinetic agents have been used in the management of gastroesophageal reflux. Soy formulas or elemental formulas are recommended for the infant with a milk protein allergy

• Question 6:

  Match the antidepressant with the side effect or characteristic that need to avoid tyramine with this medication

  A. phenelzine

  B. venlafaxine

  C. trazodone

  D. fluoxetine

  E. mirtazapine

  F. nortriptyline

  G. escitalopram

  Correct Answer: A

  Fluoxetine has the longest half-life of the current SSRIs (escitalopram's half-life is shorter--less than 24 hours), phenelzine is an MAOI and foods rich in tyramine can induce a hypertensive crisis. Venlafaxine can induce hypertension, especially at higher doses. Trazodone can rarely induce priapism (a painful sustained erection). Nortriptyline is a tricyclic antidepressant, and at high doses, it can cause arrhythmias.

• Question 7:

  A 45-year-old woman comes to your office saying that she has once again got into a deep funk, losing sleep and weight, and feeling she is worthless. She reports this is the third time in her life that she has experienced such episodes, but she has never had periods of abnormally elevated moods. 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

  Correct Answer: A

  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 8:

  A65-year-old man is referred for a psychiatric evaluation by his primary care doctor. The doctor has noted that his patient seems less concerned about his personal hygiene, his clothes are mismatched, and he is no longer getting to his doctor's appointments on time. In addition, the patient seems depressed, cries, and "no longer enjoys a good joke." Which of the following is the most therapeutic opening question in interviewing this man?

  A. "Tell me about your depression."

  B. "Why are you crying?"

  C. "Tell me what's been happening that brings you here."

  D. "Your doctor tells me you don't match your clothes anymore--why not?"

  E. "Your doctor says you're depressed. How about an antidepressant to help you?"

  Correct Answer: C

  In starting an interview, generally an openended question will allow the patient the freedom to tell his or her story. Choice A assumes the person is depressed; the patient may object if he or she feels already diagnosed and hasn't had the opportunity to talk. Choices B and D may be seen as critical and do not directly address the issue of what brings this patient to the psychiatrist. The patient may experience these as unempathetic. Choice E is premature. As the consulting psychiatrist, you must perform a thorough evaluation to determine the nature and treatment of this patient's problem.

• Question 9:

  Multiple disease outcomes associated with smoking can be assessed with which type of study?

  A. cross-sectional study

  B. randomized, controlled trial

  C. cohort study

  D. case-control study

  E. case series

  Correct Answer: C

  In a randomized, controlled trial, the determination of treatment group assignment is left to chance. The procedure maximizes the probability that the two groups are similar in important background characteristics. Thus, it avoids self-selection of study subjects to different exposure groups. In a cross-sectional study design, it is generally difficult to ascertain the antecendent-consequent aspects of the hypothesized relationship. In other words, since the exposure and outcome are measured at a given point in time, it is difficult to determine which came first. Acohort study classifies study subjects by exposure status and follows them forward in time to determine development of disease. More than one disease can be targeted as outcomes of interest. Acase-control study defines cases and controls and retrospectively assesses the frequency of exposure. Multiple exposures can be assessed in connection with a specific disease.

• Question 10:

  A 48-year-old woman with five children complains of urinary incontinence with coughing and stair climbing. She likely has genuine stress urinary incontinence if which of the following is true?

  A. Loss of urine is secondary to involuntary bladder contractions.

  B. Loss of urine is associated with a strong desire to void immediately.

  C. Loss of urine occurs in relation to anxiety or depression.

  D. Loss of urine occurs when intravesical pressure exceeds maximal urethral pressure.

  E. Loss of urine is due to increased intravesical pressure associated with bladder distention.

  Correct Answer: D

  GSI occurs when there is immediate involuntary loss of urine with increased intravesical pressure greater than maximal urethral pressure in the absence of detrusor contractions. These women can usually stop the flow of urine by voluntary contraction of the muscles that close the urethra. Loss of urine with a strongdesire to void immediately suggests urge incontinence, often occurring as a result of detrusor contractions. Loss of urine associated with seemingly unrelated conditions should raise the suspicion of a drug-associated incontinence. Maximal bladder distention and greatly increased bladder capacity suggest a diagnosis of an atonic bladder with overflow incontinence