USMLE USMLE Certifications USMLE-STEP-2 Questions & Answers

• Question 111:

  A 45-year-old man presents to the physician's office complaining of dysphagia and retrosternal pressure and pain of 2-year duration. The symptoms have worsened over the last 3 months. He has a 30 packyear smoking history and drinks beer on weekends. Vital signs include a BP of 150/90 mmHg, pulse rate of 90/ min, and respiratory rate of 12/min, with a normal temperature. Examination reveals a thin man with a normal heart, lung, and abdomen examination. An esophagogram reveals a 6-cm, smooth, concave defect in the midesophagus with sharp borders. Esophagoscopy reveals intact overlying mucosa and a mobile tumor. Which of the following is the most likely diagnosis?

  A. esophageal carcinoma

  B. bronchogenic carcinoma with invasion of the esophagus

  C. benign esophageal polyp

  D. leiomyoma

  E. lymphoma

  Correct Answer: D

  Leiomyomas are the most common benign tumors of the esophagus. They are intramural, occur between 20 and 50 years of age, and may be symptomatic when over 5 cm. Symptoms may include dysphagia and retrosternal pressure and pain. Esophagogram shows characteristic features of a smooth concave defect with sharp borders. Esophagoscopy is indicated to rule out carcinoma. These tumors are mobile, with intact overlying mucosa. Biopsy should not be performed so that subsequent extramural resection can be performed without complication. Excision is recommended for symptomatic leiomyomas or those greater than 5 cm.

• Question 112:

  A 39-year-old woman presents to the physician's office for evaluation of a palpable nodule in the neck of 2 years' duration. Her past history is pertinent for Hashimoto's disease diagnosed 5 years ago, for which she takes thyroid hormone. She has a history of low-dose chest irradiation for an enlarged thymus gland during infancy. On examination, a 2.5-cm nodule is palpable in the left lobe of the thyroid and is firm and nontender. Which of the following portions of her history increases the risk for thyroid cancer?

  A. age group of 2040 years

  B. female gender

  C. low-dose irradiation during infancy

  D. chronicity of the nodule

  E. past history of Hashimoto's disease

  Correct Answer: C

  Factors that increase the risk for carcinoma include exposure to low-dose irradiation, age under 20 or over 60, male gender (especially over age 40), and recent onset. An increased incidence of thyroid carcinoma in patients with Hashimoto's thyroiditis has not been substantiated. For diagnosis, FNA is highly accurate and has become the preferred diagnostic modality. FNA is the most important diagnostic test for selecting patients for operation, supplanting all other diagnostic tests.

• Question 113:

  A 65-year-old man presents to the emergency department with an abrupt onset of excruciating chest pain 1 hour ago. The pain is localized to the anterior chest, but radiates to the back and neck. On examination, the patient is afebrile, with a BP of 210/110 mmHg, pulse rate of 95/min, and a respiratory rate of 12/min. He appears pale and sweaty. Unequal carotid, radial, and femoral pulses are noted. An electrocardiogram (ECG) shows nonspecific ST-T segment changes. Chest x-ray shows a slightly widened mediastinum and

  normal lung fields.

  Which of the following is the first step in management of this patient?

  A. treatment with thrombolytic agents

  B. systemic anticoagulation

  C. control of hypertension

  D. placement of an intra-aortic balloon pump

  E. immediate operation

  Correct Answer: C

  The diagnosis of an aortic dissection is strongly suggested by the history of an abrupt onset of excruciating pain in the chest and back with variable radiation patterns, and a hypertensive, illappearing patient. A chest x-ray showing a widened mediastinum may be noted, but the radiograph may be normal. The differential diagnosis of an acute myocardial infarction must be entertained and an ECG performed. Though aortography has historically been the definitive diagnostic procedure and may be required in some patients, transesophageal echocardiography has become the preferred diagnostic modality. It can be performed in the emergency department, thus obviating the need to move an extremely ill patient. CT scan may also be helpful in establishing the diagnosis. Immediate drug therapy to control hypertension is mandatory, followed by definitive therapy, depending on the type of dissection. Involvement with the ascending aorta mandates immediate surgical repair. Dissections involving only the descending aorta can be managed medically, initially.Thrombolytic therapy and anticoagulation are not indicated and may precipitate exsanguination.

• Question 114:

  A 65-year-old man presents to the emergency department with an abrupt onset of excruciating chest pain

  1 hour ago. The pain is localized to the anterior chest, but radiates to the back and neck. On examination,

  the patient is afebrile, with a BP of 210/110 mmHg, pulse rate of 95/min, and a respiratory rate of 12/min.

  He appears pale and sweaty. Unequal carotid, radial, and femoral pulses are noted. An electrocardiogram

  (ECG) shows nonspecific ST-T segment changes. Chest x-ray shows a slightly widened mediastinum and

  normal lung fields.

  Which of the following is the preferred modality in establishing the diagnosis?

  A. transcutaneous echocardiography

  B. transesophageal echocardiography

  C. CT scan

  D. coronary angiography

  E. aortography

  Correct Answer: B

  The diagnosis of an aortic dissection is strongly suggested by the history of an abrupt onset of excruciating pain in the chest and back with variable radiation patterns, and a hypertensive, illappearing patient. A chest x-ray showing a widened mediastinum may be noted, but the radiograph may be normal. The differential diagnosis of an acute myocardial infarction must be entertained and an ECG performed. Though aortography has historically been the definitive diagnostic procedure and may be required in some patients, transesophageal echocardiography has become the preferred diagnostic modality. It can be performed in the emergency department, thus obviating the need to move an extremely ill patient. CT scan may also be helpful in establishing the diagnosis. Immediate drug therapy to control hypertension is mandatory, followed by definitive therapy, depending on the type of dissection. Involvement with the ascending aorta mandates immediate surgical repair. Dissections involving only the descending aorta can be managed medically, initially.Thrombolytic therapy and anticoagulation are not indicated and may precipitate exsanguination.

• Question 115:

  A 65-year-old man presents to the emergency department with sudden onset of pain and weakness of the left lower extremity of 2-hour duration. Past history reveals chronic atrial fibrillation following a myocardial infarction 12 months ago. On examination, he is found to have a cool, pale left lower extremity with decreased strength and absent popliteal and pedal pulses. The opposite leg has a normal appearance with palpable pulses. Which of the following is the treatment of choice for this patient?

  A. r-TPA (tissue plasminogen activator) infusion following anticoagulation

  B. administration of vasodilators

  C. four-compartment fasciotomy

  D. thromboembolectomy

  E. anticoagulation and close observation

  Correct Answer: D

  The diagnosis of arterial embolism is suggested when the patient presents with an acute onset of severe pain, pallor, pulselessness, paresthesia, and paralysis (five P's). The presence of atrial fibrillation is strongly suggestive of a cardiac source of the emboli. The first step in management is immediate heparinization to prevent propagation of the clot and maintain patency of collaterals. The cornerstone of treatment is thromboembolectomy. Thrombolytic therapy is reserved for treatment of irretrievable clots in small vessels. Fasciotomy, alkalinization of the urine, and mannitol diuresis are adjuncts to treatment, particularly if there is a delay in operation, increasing the risk of a reperfusion injury. Anticoagulation has been shown to reduce the rate of recurrent embolism.

• Question 116:

  A 65-year-old man presents to the emergency department with sudden onset of pain and weakness of the left lower extremity of 2-hour duration. Past history reveals chronic atrial fibrillation following a myocardial infarction 12 months ago. On examination, he is found to have a cool, pale left lower extremity with decreased strength and absent popliteal and pedal pulses. The opposite leg has a normal appearance with palpable pulses.

  Following successful treatment for an embolus to the left femoral artery with no evidence of a reperfusion injury, which of the following long-term treatments would most likely decrease the chance of recurrent embolus?

  A. anticoagulation

  B. exercise program

  C. coronary artery bypass grafting

  D. aortofemoral bypass grafting

  E. placement of a vena cava filter

  Correct Answer: A

  The diagnosis of arterial embolism is suggested when the patient presents with an acute onset of severe pain, pallor, pulselessness, paresthesia, and paralysis (five P's). The presence of atrial fibrillation is strongly suggestive of a cardiac source of the emboli. The first step in management is immediate heparinization to prevent propagation of the clot and maintain patency of collaterals. The cornerstone of treatment is thromboembolectomy. Thrombolytic therapy is reserved for treatment of irretrievable clots in small vessels. Fasciotomy, alkalinization of the urine, and mannitol diuresis are adjuncts to treatment, particularly if there is a delay in operation, increasing the risk of a reperfusion injury. Anticoagulation has been shown to reduce the rate of recurrent embolism.

• Question 117:

  A 65-year-old man presents to the emergency department with sudden onset of pain and weakness of the left lower extremity of 2-hour duration. Past history reveals chronic atrial fibrillation following a myocardial infarction 12 months ago. On examination, he is found to have a cool, pale left lower extremity with decreased strength and absent popliteal and pedal pulses. The opposite leg has a normal appearance with palpable pulses. Which of the following is the most appropriate first step in management of this patient?

  A. echocardiography

  B. anticoagulation with heparin

  C. anticoagulation with warfarin

  D. arteriography

  E. alkalinization of the urine with IV sodium bicarbonate

  Correct Answer: B

  The diagnosis of arterial embolism is suggested when the patient presents with an acute onset of severe pain, pallor, pulselessness, paresthesia, and paralysis (five P's). The presence of atrial fibrillation is strongly suggestive of a cardiac source of the emboli. The first step in management is immediate heparinization to prevent propagation of the clot and maintain patency of collaterals. The cornerstone of treatment is thromboembolectomy. Thrombolytic therapy is reserved for treatment of irretrievable clots in small vessels. Fasciotomy, alkalinization of the urine, and mannitol diuresis are adjuncts to treatment, particularly if there is a delay in operation, increasing the risk of a reperfusion injury. Anticoagulation has been shown to reduce the rate of recurrent embolism.

• Question 118:

  A 75-year-old man is brought to the emergency department for severe pain in the left flank and back of 1 hour duration. He has a prior history of a myocardial infarction and coronary artery bypass grafting 8 years ago. On examination, he is found to have a BP of 80/50 mmHg, pulse rate of 110/min, respiratory rate of 15/min, and a pulsatile, tender abdominal mass. He has had two large-bore IV lines placed by the paramedics. He is alert and oriented, and gives consent for surgery. On postoperative day 3, the patient develops dark-colored diarrhea but remains normotensive, on full mechanical ventilation, and is awake. Laboratory analysis reveals normal electrolytes, blood urea nitrogen (BUN), and creatinine; hematocrit of 30; and WBC of 15,000. Which is the most appropriate next step in management?

  A. difficile toxin test and institution of metronidazole

  B. sigmoidoscopy

  C. air contrast barium enema

  D. CT scan

  E. abdominal x-rays

  Correct Answer: B

  The clinical manifestations of ruptured abdominal aneurysm are back, flank, or abdominal pain; hypotension; and a pulsatile abdominal mass. The treatment should be immediate transfer to the operating room for laparotomy. Ultrasound can be done quickly in the ER to confirm the diagnosis. If the patient is hemodynamically stable, and the diagnosis is in doubt, a CT scan can be performed, but is generally not needed. Angiogram is not indicated unless endovascular repair is being considered, and then it should be performed in the operating room. Following successful treatment, diarrhea may suggest ischemic colitis, and urgent sigmoidoscopy is indicated. Adelay in diagnosis of bowel ischemia caused by numerous other diagnostic tests may increase the mortality rate. If bowel ischemia is found, immediate colon resection should be undertaken.

• Question 119:

  A 75-year-old man is brought to the emergency department for severe pain in the left flank and back of 1 hour duration. He has a prior history of a myocardial infarction and coronary artery bypass grafting 8 years ago. On examination, he is found to have a BP of 80/50 mmHg, pulse rate of 110/min, respiratory rate of 15/min, and a pulsatile, tender abdominal mass. He has had two large-bore IV lines placed by the paramedics. He is alert and oriented, and gives consent for surgery. Which of the following is the most appropriate next step in management of this patient?

  A. immediate consultation with cardiology to assess cardiac risk for surgery, followed by transfer to the operating room

  B. resuscitation in the emergency department with IV fluids, transfer to radiology for a CT scan to assess for the location and degree of rupture, followed by transfer to the operating room

  C. resuscitation in the emergency department with IV fluids to achieve a systolic BP greater than 100, followed by transfer to the operating room

  D. immediate transfer to the operating room with concomitant resuscitation and laparotomy

  E. resuscitation in the emergency department with IV fluids, transfer to radiology for immediate aortic angiogram for assessment of the location of the rupture, followed by transfer to theoperating room

  Correct Answer: D

  The clinical manifestations of ruptured abdominal aneurysm are back, flank, or abdominal pain; hypotension; and a pulsatile abdominal mass. The treatment should be immediate transfer to the operating room for laparotomy. Ultrasound can be done quickly in the ER to confirm the diagnosis. If the patient is hemodynamically stable, and the diagnosis is in doubt, a CT scan can be performed, but is generally not needed. Angiogram is not indicated unless endovascular repair is being considered, and then it should be performed in the operating room. Following successful treatment, diarrhea may suggest ischemic colitis, and urgent sigmoidoscopy is indicated. Adelay in diagnosis of bowel ischemia caused by numerous other diagnostic tests may increase the mortality rate. If bowel ischemia is found, immediate colon resection should be undertaken.

• Question 120:

  A 65-year-old woman presents to the physician's office for her yearly physical examination. She has no complaints except for a recent 10-lb weight loss. Past history is pertinent for a 40 pack-year smoking history, hypertension, asthma, and hypothyroidism. Examination reveals a thin woman with normal vital signs and unremarkable heart and abdominal examinations. Lung examination reveals mild wheezing and a few bibasilar rales. A chest x-ray is obtained and is shown in Figure. Achest x-ray obtained 3 years ago was normal. Yearly laboratory tests including a CBC, electrolytes, and lipid panels are normal.

  

  Which of the following is the most appropriate next diagnostic test?

  A. percutaneous needle biopsy

  B. CT scan

  C. pulmonary function tests

  D. mediastinoscopy

  E. bronchoscopy

  Correct Answer: B

  The finding of a new, irregular lesion in a patient with a long smoking history must be considered a lung carcinoma and should be managed accordingly. Nonsmall cell carcinoma is the most common lung neoplasm. Small cell carcinomas usually grow rapidly and disseminate widely by the time of diagnosis. Tuberculosis would present with systemic symptoms and apical disease on chest x-ray. Likewise, a lung abscess would be accompanied by systemic symptoms and may show air-fluid levels in the abscess cavity. A hamartoma presents as an extremely slowly growing nodule that may contain popcorn calcifications. The most appropriate test following suspicious findings on a chest x-ray would be a CT scan to evaluate further the nodule, evaluate the lymph node status, and triage subsequent diagnostic tests. If enlarged mediastinal nodes are seen, then mediastinoscopy may be indicated. Bronchoscopy may be helpful to assess for endobronchial lesions and to obtain tissue for diagnosis. Pulmonary function tests are necessary once a decision is made to consider operation. Percutaneous needle biopsy may be required to obtain tissue once CT scanning is performed