USMLE USMLE Certifications USMLE-STEP-2 Questions & Answers

• Question 651:

  A 35-year-old man presents with acute low back pain after lifting a couch in his home. Pain is in the lumbosacral area and increases with walking and bending. Examination reveals paraspinal muscle spasm and tenderness and negative straight leg raise bilaterally. Lower extremity strength is intact. Which of the following is the best next step in managing this patient?

  A. bed rest for 1 week

  B. referral to an orthopedic specialist

  C. x-ray of lumbosacral spine

  D. treatment with anti-inflammatory medication and gradual return to normal activity

  E. referral to a pain clinic

  Correct Answer: D

  In younger patients, low back pain tends to be mild and self-limited, typically resolving in 46 weeks. Patients should be encouraged to remain active and symptom control can be achieved with pain medications. Low back pain is the leading cause of work-related disability in the United States. The absence of alarm symptoms such as unilateral or bilateral leg weakness and bladder, bowel or sexual dysfunction makes a cauda equine syndrome or other spinal cord injury unlikely. Age >50, constant pain at night, history of cancer, unexplained weight loss, and lack of response to conservative therapy make further investigation including radiologic evaluation appropriate.

• Question 652:

  Which of the following patterns is most consistent with the physiologic profile of cardiogenic shock?

  A. CVP

  B. CO

  C. SVR

  D. SVO2

  Correct Answer: B

  Patients with cardiogenic shock B. demonstrate a pattern with increased CVP, low CO, increased SVR,

  and decreased SVO2. Those with hypovolemic shock A. demonstrate low CVP, low CO, increased SVR,

  and decreased SVO2. The distinguishing feature of early septic shock C. is an increased cardiac output.

  Patients with neurogenic shock D. have severe loss of vasomotor tone leading to the unusual combination

  of low SVR and low CO. CVP = central venous pressure, CO = cardiac output, SVR = systemic vascular

  resistance,

  SVO2 = venous O2 saturation

• Question 653:

  A 42-year-old man admitted with a high fever and leukocytosis is transferred to the intensive care unit in shock. Which of the following is a common finding in the early stages of septic shock?

  Which of the following is an appropriate initial therapy for both septic shock and cardiogenic shock?

  A. prophylactic antibiotics

  B. beta blockers

  C. volume resuscitation with crystalloid fluids

  D. mechanical ventilation

  E. diuretics

  Correct Answer: C

  The usual early hemodynamic response to sepsis is a hyperdynamic circulation. This includes tachycardia, elevated cardiac output, and decreased systemic resistance. Septic shock may then progress with intractable hypotension, metabolic acidosis, reduced cardiac output, oliguria, and death. The initial resuscitation of patients with all forms of shock requires rapid expansion of circulating blood volume to help maintain BP and tissue perfusion. This is usually achieved with the infusion of crystalloid fluids. When septic shock is suspected, cultures of blood, urine, and other sources along with antibiotic therapy targeted toward the most likely source is critical. Mechanical ventilation may be required when altered mental status, acidosis, and hypoxia are present. Beta-blockers and diuretics may have specific indications that cardiac ischemia and pulmonary edema are present

• Question 654:

  A 42-year-old man admitted with a high fever and leukocytosis is transferred to the intensive care unit in shock. Which of the following is a common finding in the early stages of septic shock?

  A. reduced cardiac output

  B. bradycardia

  C. decreased systemic vascular resistance (SVR)

  D. hypertension

  E. metabolic alkalosis

  Correct Answer: C

  The usual early hemodynamic response to sepsis is a hyperdynamic circulation. This includes tachycardia, elevated cardiac output, and decreased systemic resistance. Septic shock may then progress with intractable hypotension, metabolic acidosis, reduced cardiac output, oliguria, and death. The initial resuscitation of patients with all forms of shock requires rapid expansion of circulating blood volume to help maintain BP and tissue perfusion. This is usually achieved with the infusion of crystalloid fluids. When septic shock is suspected, cultures of blood, urine, and other sources along with antibiotic therapy targeted toward the most likely source is critical. Mechanical ventilation may be required when altered mental status, acidosis, and hypoxia are present. Beta-blockers and diuretics may have specific indications that cardiac ischemia and pulmonary edema are present

• Question 655:

  A 65-year-old woman with a long history of uncontrolled hypertension and valvular heart disease presents for evaluation. She is fatigued and complains of swelling in her legs and shortness of breath. Which of the following is the distinguishing feature of left ventricular failure?

  A. elevated liver enzymes

  B. pulmonary edema

  C. ascites

  D. peripheral edema

  E. jugular venous distention

  Correct Answer: B

  Physical findings are often helpful in distinguishing left-sided from right-sided heart failure. When the left ventricle is either overloaded or weakened, patients develop dyspnea and orthopnea as a result of pulmonary congestion. When the underlying abnormality is primarily right ventricular failure symptoms related to pulmonary congestion are uncommon and patients experience edema, venous distention, and hepatic congestion. Liver enzymes may be elevated secondary to hepatic congestion

• Question 656:

  A 25-year-old man has the sudden onset of chest pain on the right side and dyspnea. On CXR, his trachea is deviated to the left. Which of the following should be anticipated on examination?

  A. rales on the left

  B. rales on the right

  C. hyperresonance on the left

  D. distant breath sounds on the right

  E. pleural friction rub on the left

  Correct Answer: D

  In the patient described in the question, the movement of the trachea to the left suggests a difference between right and left pleural pressures, either a reduction in pressure on the left or a rise in pressure on the right. The acute onset of right-sided chest pain in an otherwise healthy young man suggests a pneumothorax. On the side of the pneumothorax, we would expect increased resonance and distant or absent breath sounds because of the air trapped in the pleural space between the lung and chest wall and possible compression of the normal lung. No rales or rhonchi would be expected. Apleural friction rub suggests an inflammatory process involving the left chest, a finding not likely on the basis of the patient's presentation.

• Question 657:

  A55-year-old man with a 50 pack-year history of smoking presents with hemoptysis. CXR shows a left upper lobe mass and laboratory evaluation reveals hypercalcemia. Which of the following is the most likely diagnosis?

  A. small cell lung cancer

  B. tuberculosis

  C. squamous cell lung cancer

  D. adenocarcinoma of the lung

  E. metastatic testicular cancer

  Correct Answer: C

  Although 515% of patients with lung cancer are identified while they are asymptomatic, most patients present with signs and symptoms including cough, hemoptysis, wheeze, stridor, shortness of breath, and postobstructive pneumonia. Paraneoplastic syndromes are common among patients with lung cancer. Endocrine paraneoplastic syndromes are seen in 12% of patients. Hypercalcemia may result from ectopic production of PTH or PTH-related peptides by squamous cell carcinomas. Small cell cancers may secrete ACTH or excessive amounts of ADH leading to hyponatremia and SIADH. Other nonendocrine paraneoplastic manifestations may include anorexia, cachexia, weight loss, fever, suppressed immunity. peripheral neuropathy, and the myasthenic Eaton-Lambert syndrome.

• Question 658:

  A26-year-old man presents with a hard, painless testicular mass. At operation, frozen section reveals testicular cancer. Which of the following is a risk factor?

  What serum marker can be used to monitor therapy?

  A. carcinoembryonic antigen (CEA)

  B. human chorionic gonadotropin (hCG)

  C. sedimentation rate

  D. lactic dehydrogenase (LDH)

  E. prostate-specific antigen (PSA)

  Correct Answer: B

  Testicular cancer is the most common cancer in men between the ages of 20 and 40. Predisposing factors include cryptorchidism, hernias, and testicular atrophy. Abdominal testes are at higher risk than inguinal cryptorchid testes. Family history of testicular or prostate cancer, radiation exposure, or maternal DES seems to play no role. Testicular cancers are divided into nonseminoma and seminoma subtypes. Seminoma represents about 50% of all tumors and generally follows a more indolent course. The primary tumor is treated by inguinal orchiectomy regardless of cell type. Pure seminomas do not require retroperitoneal lymph node dissection, because radiation is usually adequate therapy. Nonseminomatous testicular tumors (embryonal cell, teratocarcinoma, choriocarcinoma, endodermal sinus) are usually treated by retroperitoneal dissection. Serum alpha-fetoprotein (AFP) and hCG levels are markers that are important for diagnosis and as prognostic indicators and are used to monitor therapy. Serum LDH level is often elevated with bulky tumors but is not as specific as either AFP or hCG. CEA is a nonspecific marker elaborated by many adenocarcinomas. PSA is a marker associated with prostate cancer

• Question 659:

  A26-year-old man presents with a hard, painless testicular mass. At operation, frozen section reveals testicular cancer. Which of the following is a risk factor?

  A. family history of testicular cancer

  B. masturbation

  C. prior history of radiation exposure

  D. cryptorchidism E. maternal diethylstilbestrol (DES) during pregnancy

  Correct Answer: D

  Testicular cancer is the most common cancer in men between the ages of 20 and 40. Predisposing factors include cryptorchidism, hernias, and testicular atrophy. Abdominal testes are at higher risk than inguinal cryptorchid testes. Family history of testicular or prostate cancer, radiation exposure, or maternal DES seems to play no role. Testicular cancers are divided into nonseminoma and seminoma subtypes. Seminoma represents about 50% of all tumors and generally follows a more indolent course. The primary tumor is treated by inguinal orchiectomy regardless of cell type. Pure seminomas do not require retroperitoneal lymph node dissection, because radiation is usually adequate therapy. Nonseminomatous testicular tumors (embryonal cell, teratocarcinoma, choriocarcinoma, endodermal sinus) are usually treated by retroperitoneal dissection. Serum alpha-fetoprotein (AFP) and hCG levels are markers that are important for diagnosis and as prognostic indicators and are used to monitor therapy. Serum LDH level is often elevated with bulky tumors but is not as specific as either AFP or hCG. CEA is a nonspecific marker elaborated by many adenocarcinomas. PSA is a marker associated with prostate cancer

• Question 660:

  A26-year-old man presents with a hard, painless testicular mass. At operation, frozen section reveals testicular cancer. Which of the following is a risk factor? What is the most common cell type in testicular cancer?

  A. choriocarcinoma

  B. embryonal cell

  C. seminoma

  D. teratocarcinoma

  E. endodermal sinus

  Correct Answer: C

  Testicular cancer is the most common cancer in men between the ages of 20 and 40. Predisposing factors include cryptorchidism, hernias, and testicular atrophy. Abdominal testes are at higher risk than inguinal cryptorchid testes. Family history of testicular or prostate cancer, radiation exposure, or maternal DES seems to play no role. Testicular cancers are divided into nonseminoma and seminoma subtypes. Seminoma represents about 50% of all tumors and generally follows a more indolent course. The primary tumor is treated by inguinal orchiectomy regardless of cell type. Pure seminomas do not require retroperitoneal lymph node dissection, because radiation is usually adequate therapy. Nonseminomatous testicular tumors (embryonal cell, teratocarcinoma, choriocarcinoma, endodermal sinus) are usually treated by retroperitoneal dissection. Serum alpha-fetoprotein (AFP) and hCG levels are markers that are important for diagnosis and as prognostic indicators and are used to monitor therapy. Serum LDH level is often elevated with bulky tumors but is not as specific as either AFP or hCG. CEA is a nonspecific marker elaborated by many adenocarcinomas. PSA is a marker associated with prostate cancer