USMLE USMLE Certifications USMLE-STEP-2 Questions & Answers

• Question 91:

  A 23-year-old man presents to the emergency department with a soft-tissue injury to the left lower extremity. The injury was sustained 8 hours earlier in a motorcycle accident on a gravel road. On examination, the patient has a 7-cm deep laceration to the calf, with visible road debris. He had full tetanus immunization as a child and a tetanus booster immunization at age 15. Appropriate management of this injury would include which of the following?

  A. irrigation and debridement of the wound

  B. irrigation and debridement of the wound; tetanus toxoid and tetanus immune globulin

  C. irrigation and debridement of the wound; tetanus toxoid

  D. irrigation and debridement of the wound; IV antibiotics

  E. tetanus toxoid and IV antibiotics

  Correct Answer: C

  All traumatic soft-tissue injuries should be managed with aggressive local wound care. Because this injury is greater than 6hours old, contaminated, and greater than 1 cm in depth, it is a tetanus-prone wound. Therefore, in addition, this patient should receive tetanus toxoid, because it has been more than 5 years since his last immunization. He had full immunization as a child and, therefore, does not require additional passive immunization with tetanus immune globulin. Prophylactic antibiotics are controversial in the absence of an established wound infection.

• Question 92:

  A 65-year-old diabetic man presents to the emergency department with a history of a penetrating wound to his buttock by a wooden stump while working in his garden 24 hours earlier. On examination, he is febrile, the tissue around the wound is violaceous in color, and several bullae and crepitus are noted in the buttock. The drainage from the wound is foul smelling, watery, and grayish in appearance.

  The optimal treatment for this patient would include which of the following?

  A. high-dose IV penicillin G and broadspectrum antibiotics

  B. high-dose IV penicillin G, broadspectrum antibiotics, and local wound care with unroofing of bullae and culture of wound drainage

  C. high-dose IV penicillin G, broadspectrum antibiotics, with surgical debridement only if and when there is no improvement with antibiotics

  D. radical surgical debridement

  E. high-dose IV penicillin G, broadspectrum antibiotics, radical surgical debridement, and hyperbaric oxygen therapy

  Correct Answer: E

  This patient presents with a rapidly progressive, necrotizing soft-tissue infection. The skin edema, purple

  hue, bullae, water drainage, and crepitus are classic findings in clostridial infections. Although culture of

  the wound drainage may be confirmatory, the diagnosis should be suspected on a clinical basis.

  Antibiotics alone are insufficient therapy. The mainstay of therapy is radical surgical debridement of

  devitalized tissues, in conjunction with high-dose IV antibiotics.

  Hyperbaric oxygen therapy may facilitate recovery.

• Question 93:

  A 10-month-old infant presents to the emergency department with a 24-hour history of low-grade fever and anorexia. The parents report several episodes in which the child has been suddenly inconsolable and crying, followed by periods of lethargy. He has had nonbilious vomiting and several loose stools. On examination, the infant is pale and mildly dehydrated. His abdomen is soft and nondistended, with fullness to palpation in the right upper quadrant. The child passed another stool in the emergency department Which of the following is the most appropriate next step in the diagnostic evaluation and management of this patient?

  

  A. proctoscopy

  B. oral rehydration and stool cultures

  C. IV fluid rehydration and a hydrostatic barium enema

  D. technetium scan

  E. IV fluid rehydration, NG decompression, and a UGI contrast study

  Correct Answer: C

  Intussusception most commonly occurs between 2 months and 2 years of age, often associated with a prodromal viral illness. Children will present with intermittent episodes of abdominal colic, secondary to peristaltic waves of the ileum against the partially obstructing ileocolic lesion. Reflex nonbilious vomiting is secondary to bowel distention and partial obstruction. There may be a palpable, right-sided, "sausageshaped" mass, but in many patients, the abdominal examination is entirely normal. The classic "currant jelly" stool is a late sign and is a result of ischemia and mucosal sloughing of the lead point. After the child has received IV fluid resuscitation, the management is hydrostatic reduction, either by contrast enema or air enema. Intussusception may occur during the clinical course of viral gastroenteritis. Bloody stools are more commonly associated with bacterial gastrointestinal infections, with characteristically loose, mucousy stools, and blood mixed with fecal material. Diagnosis is aided by obtaining stool cultures. A midgut volvulus can be associated with passage of a "currant jelly" stool secondary to small-bowel ischemia. However, these children usually present with bilious vomiting. Diagnosis may be confirmed with a UGI contrast study. Rectal bleeding from a Meckel's diverticulum is typically painless, without other associated gastrointestinal symptoms. Technetium scan is useful for diagnosis. Bleeding from a juvenile rectal polyp is usually small in amount and often occurs during normal stool passage. The children are clinically well, without other gastrointestinal symptoms. These polyps may be seen on proctoscopy.

• Question 94:

  A 10-month-old infant presents to the emergency department with a 24-hour history of low-grade fever and anorexia. The parents report several episodes in which the child has been suddenly inconsolable and crying, followed by periods of lethargy. He has had nonbilious vomiting and several loose stools. On examination, the infant is pale and mildly dehydrated. His abdomen is soft and nondistended, with fullness to palpation in the right upper quadrant. The child passed another stool in the emergency department

  

  Which of the following is the most likely diagnosis?

  A. gastroenteritis

  B. intussusception

  C. midgut volvulus

  D. Meckel's diverticulum

  E. juvenile rectal polyp

  Correct Answer: B

  Intussusception most commonly occurs between 2 months and 2 years of age, often associated with a prodromal viral illness. Children will present with intermittent episodes of abdominal colic, secondary to peristaltic waves of the ileum against the partially obstructing ileocolic lesion. Reflex nonbilious vomiting is secondary to bowel distention and partial obstruction. There may be a palpable, right-sided, "sausageshaped" mass, but in many patients, the abdominal examination is entirely normal. The classic "currant jelly" stool is a late sign and is a result of ischemia and mucosal sloughing of the lead point. After the child has received IV fluid resuscitation, the management is hydrostatic reduction, either by contrast enema or air enema. Intussusception may occur during the clinical course of viral gastroenteritis. Bloody stools are more commonly associated with bacterial gastrointestinal infections, with characteristically loose, mucousy stools, and blood mixed with fecal material. Diagnosis is aided by obtaining stool cultures. A midgut volvulus can be associated with passage of a "currant jelly" stool secondary to small-bowel ischemia. However, these children usually present with bilious vomiting. Diagnosis may be confirmed with a UGI contrast study. Rectal bleeding from a Meckel's diverticulum is typically painless, without other associated gastrointestinal symptoms. Technetium scan is useful for diagnosis. Bleeding from a juvenile rectal polyp is usually small in amount and often occurs during normal stool passage. The children are clinically well, without other gastrointestinal symptoms. These polyps may be seen on proctoscopy.

• Question 95:

  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 best next step in the management of this patient?

  A. antibiotics

  B. excisional biopsy

  C. observation with re-evaluation in 24 weeks

  D. superficial parotidectomy

  E. chest x-ray

  Correct Answer: D

  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 96:

  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

  Correct Answer: C

  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 97:

  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. The imaging studies demonstrate three lesions in the right hepatic lobe suspicious for metastatic disease, each measuring 34 cm in diameter. There was no evidence of extrahepatic disease. Which of the following is the most appropriate next step in management?

  A. systemic chemotherapy

  B. intra-arterial chemotherapy through the hepatic artery

  C. surgical resection

  D. radiation therapy to the liver

  E. repeat imaging studies in 3 months to determine the growth rate of the disease

  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 98:

  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. Which of the following is the most appropriate next diagnostic test in this patient?

  A. positron emission tomography (PET) scan

  B. radionuclide liver scan

  C. ultrasound

  D. CT scan

  E. MRI scan

  Correct Answer: D

  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 99:

  A55-year-old man presents to the physician's office complaining of upper abdominal pain of 2 months' duration. The pain is described as gnawing, localized to the upper midline, and associated with nausea. The pain is exacerbated by food, and there is an associated 20-lb weight loss over 2 months. His past history is pertinent for a 30 pack-year smoking history, occasional alcohol intake, and a prior history of a benign gastric ulcer 5 years ago. Physical examination reveals normal vital signs, mild epigastric pain with deep palpation, and mildly hemepositive stool. An evaluation for recurrence of a gastric ulcer is recommended. In this patient, a benign gastric ulcer was found, and he was placed on a proton-pump inhibitor and triple antibiotics for Helicobacter pylori. He returns to the physician's office 3 months later with similar complaints and, on re-evaluation, the gastric ulcer was found to persist. Which of the following is the most appropriate next step in management?

  A. a second trial of proton-pump inhibitors with triple antibiotics and re-evaluation in 2 months

  B. a trial of H2 blockers with triple antibiotics and re-evaluation in 2 months

  C. a trial of sucralfate and re-evaluation in 2 months

  D. surgical management

  E. a trial of prostaglandins and re-evaluation in 2 months

  Correct Answer: D

  Gastric ulcers present with symptoms of abdominal pain, aggravated by food, and associated with nausea, vomiting, anorexia, and weight loss. The two principal means of diagnosing a gastric ulcer are UGI radiographs and fiberoptic endoscopy, the latter being the most reliable method. CT scan and endoscopic ultrasound may be helpful in staging gastric cancer, but are not routinely used with benign disease. The failure to respond to 12 weeks of medical management is an indication for surgical therapy to avoid potential complications and to exclude malignancy, despite biopsies obtained by endoscopy that show benign disease.

• Question 100:

  A55-year-old man presents to the physician's office complaining of upper abdominal pain of 2 months' duration. The pain is described as gnawing, localized to the upper midline, and associated with nausea. The pain is exacerbated by food, and there is an associated 20-lb weight loss over 2 months. His past history is pertinent for a 30 pack-year smoking history, occasional alcohol intake, and a prior history of a benign gastric ulcer 5 years ago. Physical examination reveals normal vital signs, mild epigastric pain with

  deep palpation, and mildly hemepositive stool. An evaluation for recurrence of a gastric ulcer is

  recommended.

  Which of the following tests is the most reliable method for diagnosing a gastric ulcer?

  A. UGI barium x-rays

  B. fiberoptic upper endoscopy

  C. CT scan

  D. endoscopic ultrasound

  E. MRI

  Correct Answer: B

  Gastric ulcers present with symptoms of abdominal pain, aggravated by food, and associated with nausea, vomiting, anorexia, and weight loss. The two principal means of diagnosing a gastric ulcer are UGI radiographs and fiberoptic endoscopy, the latter being the most reliable method. CT scan and endoscopic ultrasound may be helpful in staging gastric cancer, but are not routinely used with benign disease. The failure to respond to 12 weeks of medical management is an indication for surgical therapy to avoid potential complications and to exclude malignancy, despite biopsies obtained by endoscopy that show benign disease.