USMLE USMLE Certifications USMLE-STEP-2 Questions & Answers

• Question 141:

  A 65-year-old woman presents to the physician's office for a second opinion on the management options for recently diagnosed breast cancer. She presents with a 2.5-cm mass in the upper outer quadrant of the left breast associated with a palpable axillary node suspicious for metastatic disease. The remainder of her examination is normal. Mammography demonstrates the cancer and shows no other suspicious lesions in either breast. Chest x-ray, bone scan, and blood test panel, including liver function tests, are normal. Family history is positive for breast cancer diagnosed in her sister at age 65. Past history is unremarkable. The first physician recommended modified radical mastectomy. The patient has read about SLN biopsy. She avidly wants to avoid the risk of lymphedema that her sister must endure. She asks the question "Am I a candidate for a SLN biopsy instead of a complete axillary dissection?"

  Which of the following is the most appropriate answer to her question?

  A. Yes, and if the SLN if positive, then a complete axillary dissection should be performed.

  B. Yes, and if the SLN is negative, then an axillary dissection can be avoided.

  C. No, because the success of SLN biopsy in patients over age 60 is decreased.

  D. No, because SLN biopsy is contraindicated when a palpable axillary node issuspicious for metastatic disease.

  E. No, because SLN biopsy is contraindicated for tumors greater than 2 cm.

  Correct Answer: D

  Prospective randomized trials have addressed the issue of locoregional control of breast cancer. Conservative management consisting of lumpectomy (with negative margins), irradiation, and axillary node dissection is equally effective as modified radical mastectomy in patients with clinical stage I or II breast carcinoma. Although radical mastectomy yields equivalent survival to modified radical mastectomy, it is disfiguring and disabling and is rarely employed for treatment of primary operable breast cancer. Lumpectomy without irradiation leads to unacceptably high local recurrence rates. Irradiation without surgery is not as effective as surgery in the presence of gross disease. Quadrantectomy removes excessive tissue and leads to an inferior cosmetic result as compared to lumpectomy. If quadrantectomy is thought to be required to gain negative margins, mastectomy with reconstruction should be entertained. The use of SLN biopsy to stage the axilla in breast cancer is gaining wider acceptance as experience with the procedure grows. Trials are ongoing that will answer numerous questions regarding the accuracy and efficacy of SLN biopsy for breast cancer. There are contraindications to SLN biopsy that include palpable adenopathy that is suspicious for metastatic disease, locally advanced disease or tumor size >5 cm, multicentric disease, pregnant or lactating patient, and use of preoperative chemotherapy. Therefore, in this patient with palpable suspicious adenopathy, SLN biopsy would be contraindicated. Although age may influence success of SLN biopsy, increasing age does not preclude the procedure.

• Question 142:

  A 65-year-old woman presents to the physician's office for a second opinion on the management options for recently diagnosed breast cancer. She presents with a 2.5-cm mass in the upper outer quadrant of the left breast associated with a palpable axillary node suspicious for metastatic disease. The remainder of her examination is normal. Mammography demonstrates the cancer and shows no other suspicious lesions in either breast. Chest x-ray, bone scan, and blood test panel, including liver function tests, are normal. Family history is positive for breast cancer diagnosed in her sister at age 65. Past history is unremarkable. The first physician recommended modified radical mastectomy. Which of the following is the most appropriate management option for locoregional control yielding results equally effective as mastectomy?

  A. radical mastectomy

  B. lumpectomy, irradiation, and axillary node dissection

  C. lumpectomy and axillary node dissection

  D. irradiation of the breast and axilla

  E. quadrantectomy, irradiation, and axillary node dissection

  Correct Answer: B

  Prospective randomized trials have addressed the issue of locoregional control of breast cancer. Conservative management consisting of lumpectomy (with negative margins), irradiation, and axillary node dissection is equally effective as modified radical mastectomy in patients with clinical stage I or II breast carcinoma. Although radical mastectomy yields equivalent survival to modified radical mastectomy, it is disfiguring and disabling and is rarely employed for treatment of primary operable breast cancer. Lumpectomy without irradiation leads to unacceptably high local recurrence rates. Irradiation without surgery is not as effective as surgery in the presence of gross disease. Quadrantectomy removes excessive tissue and leads to an inferior cosmetic result as compared to lumpectomy. If quadrantectomy is thought to be required to gain negative margins, mastectomy with reconstruction should be entertained. The use of SLN biopsy to stage the axilla in breast cancer is gaining wider acceptance as experience with the procedure grows. Trials are ongoing that will answer numerous questions regarding the accuracy and efficacy of SLN biopsy for breast cancer. There are contraindications to SLN biopsy that include palpable adenopathy that is suspicious for metastatic disease, locally advanced disease or tumor size >5 cm, multicentric disease, pregnant or lactating patient, and use of preoperative chemotherapy. Therefore, in this patient with palpable suspicious adenopathy, SLN biopsy would be contraindicated. Although age may influence success of SLN biopsy, increasing age does not preclude the procedure.

• Question 143:

  A 35-year-old woman presents to the clinic for a discussion on breast cancer risk. Her family history is pertinent for a grandmother who died of breast cancer at age 53, a mother who died of premenopausal breast cancer, and one of three sisters with breast cancer diagnosed at age 42. The sister with breast cancer underwent genetic testing and was found to have a BRCA1 mutation. Subsequently, the 35- year-old woman underwent genetic testing and was found to be a carrier of the same deleterious BRCA1 mutation. For this patient, which of the following strategies represent an accepted management option for her high-risk status?

  A. yearly self-breast examinations

  B. semiannual mammography

  C. bilateral breast irradiation

  D. prophylactic unilateral mastectomy

  E. chemoprevention with tamoxifen

  Correct Answer: E

  Deleterious mutations in the BRCA1 and BRCA2 genes are associated with markedly elevated lifetime risks of breast cancer. The risk initially quoted was determined from families with high penetrance or expression of the disease, in the 8090% range. Asubsequent study, based on a larger population of gene mutation carriers, demonstrated a lower risk of 56%. Therefore, the risk generally quoted for mutation carriers is in the range of 5080%. Management options for known mutation carriers, or other high-risk women, include intensive surveillance with monthly self-breast examinations, annual or semiannual clinical breast examinations, annual mammography starting 10 years prior to the earliest age of onset of breast cancer in a family member, chemoprevention with tamoxifen, and prophylactic mastectomy. The data supporting these options in BRCA-mutation carriers, however, are limited to small series. Evidence for imaging of these high-risk women using MRI as a screening modality is promising.

• Question 144:

  A 35-year-old woman presents to the clinic for a discussion on breast cancer risk. Her family history is pertinent for a grandmother who died of breast cancer at age 53, a mother who died of premenopausal breast cancer, and one of three sisters with breast cancer diagnosed at age 42. The sister with breast cancer underwent genetic testing and was found to have a BRCA1 mutation. Subsequently, the 35- year-old woman underwent genetic testing and was found to be a carrier of the same deleterious BRCA1 mutation. Which of the following ranges represents the lifetime risk for breast cancer that should be quoted for this patient?

  A. 030%

  B. 1040%

  C. 2050%

  D. 5080%

  E. 70100%

  Correct Answer: D

  Deleterious mutations in the BRCA1 and BRCA2 genes are associated with markedly elevated lifetime risks of breast cancer. The risk initially quoted was determined from families with high penetrance or expression of the disease, in the 8090% range. Asubsequent study, based on a larger population of gene mutation carriers, demonstrated a lower risk of 56%. Therefore, the risk generally quoted for mutation carriers is in the range of 5080%. Management options for known mutation carriers, or other high-risk women, include intensive surveillance with monthly self-breast examinations, annual or semiannual clinical breast examinations, annual mammography starting 10 years prior to the earliest age of onset of breast cancer in a family member, chemoprevention with tamoxifen, and prophylactic mastectomy. The data supporting these options in BRCA-mutation carriers, however, are limited to small series. Evidence for imaging of these high-risk women using MRI as a screening modality is promising.

• Question 145:

  A56-year-old woman presents to the clinic for routine health screening. Her concern is the development of breast cancer. She has no current breast-related complaints. Past history is pertinent for fibrocystic changes with atypical ductal hyperplasia and a single fibroadenoma, both diagnosed by open biopsy 5 years ago. She smokes one pack per day and drinks one can of beer daily. Family history is positive for breast cancer in her mother, diagnosed at the age of 85. Current medications include a cholesterol lowering agent, an antihypertensive, and HRT, which she has taken for 5 years. Physical examination is unremarkable. Mammograms show dense breasts, decreasing the accuracy of the study, but no suspicious findings were noted. Which of the following is the most common risk factor in evaluating women for breast cancer?

  A. fibrocystic changes with atypical ductal hyperplasia

  B. alcohol consumption

  C. positive family history

  D. HRT

  E. age

  Correct Answer: E

  Anumber of breast cancer risk factors have been identified. These include family history, benign breast disease with atypical epithelial hyperplasia, alcohol consumption, and HRT. The most common and clinically useful risk factors are age and female gender. In most patients (70%) with breast cancer, however, no other major risk factor can be identified.

• Question 146:

  A 42-year-old woman returns to the clinic following an uneventful biopsy for a welldefined, mobile mass. The pathology report describes the mass as a fibroadenoma, but LCIS is identified in the breast parenchyma adjacent to the fibroadenoma and extending to the margin of resection. She has no current illnesses, is on no medications, and her family history is negative for breast cancer. Breast imaging studies show fatty breasts with no abnormal findings except for the fibroadenoma. Which of the following is the most appropriate management option?

  A. re-excision of the biopsy cavity to gain negative margins of resection

  B. ipsilateral mastectomy

  C. contralateral breast biopsy

  D. observation including examinations and mammography

  E. bilateral total mastectomies

  Correct Answer: D

  LCIS is considered a marker for susceptibility of the breasts for malignant change. Lobular and ductal elements of both breasts are at risk. The risk for development of cancer is approximately 1% per year, equally divided between the two breasts. Therefore, re-excision to gain negative margins is not indicated, nor is ipsilateral mastectomy. There is no known added significance to bilateral LCIS; therefore, contralateral breast biopsy is not useful for determining appropriate management. Both breasts should be treated the same. For patients without any other identifiable risk factors, close observation with frequent physician examinations, monthly breast selfexamination, and yearly mammography may be the best option. However, some patients may prefer bilateral total mastectomies as a personal preference or for situations in which they cannot adhere to close follow-up recommendations or whose risk for cancer is deemed too high.

• Question 147:

  A 56-year-old woman presents to the physician's office with complaints of a new left breast mass. She denies any pain, nipple discharge, or skin dimpling. She has a prior history of breast cysts 5 years ago, treated by aspiration at that time. Her last mammogram was at age 53. Past history is pertinent for a 30 pack-year smoking history, prior total abdominal hysterectomy-bilateral salpingo-oophorectomy (TAHBSO) at age 54 for leiomyomas, and current use of hormone replacement therapy (HRT). Family history is negative for breast disease. Examination reveals a firm, welldefined, mobile, 1.5-cm nodule in the upper outer quadrant of the left breast without any regional lymphadenopathy. Which of the following is the most appropriate next step in management?

  A. fine-needle aspiration (FNA) biopsy

  B. discontinuation of HRT and reexamination in 46 weeks

  C. breast imaging

  D. open surgical biopsy

  E. core needle biopsy

  Correct Answer: C

  A new mass in a woman of this age group must be fully evaluated to rule out carcinoma. Though biopsy by fine needle, core needle, or open biopsy will be required to determine the etiology of the mass, they should not be performed until all necessary breast imaging studies have been performed. Imaging should include diagnostic mammography and possibly sonography to determine whether the mass is solid or cystic. An appropriate type of biopsy can be chosen (i.e., FNA for cystic lesions or core biopsy for solid lesions). Imaging should not be delayed, although the patient should discontinue HRT until the etiology of the mass is determined.

• Question 148:

  A 65-year-old man presents to the physician's office with complaints of abdominal discomfort and jaundice for the past 3 weeks. Past history is pertinent for 30 pack-year smoking history, occasional alcohol intake, and a 5.5-mm ulcerating melanoma removed from his back 21/2 years ago. Examination reveals a mildly jaundiced patient with normal vital signs and a slightly distended abdomen with mild right upper quadrant tenderness and significant hepatomegaly. 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: G

  Liver dysfunction resulting in jaundice may be a manifestation of advanced metastatic disease to the liver. In a patient with a known malignancy at high risk for metastases (i.e., deeply invasive and ulcerative melanoma), metastatic disease must be considered in the evaluation of the jaundiced patient. Hepatomegaly found on abdominal examination is supportive of advanced metastatic disease.

• Question 149:

  A 75-year-old woman is brought to the emergency department from the nursing home for jaundice and mental confusion. The nursing home notes state that she has become less responsive and has developed jaundice over the last 2 weeks. Past history is pertinent for hypertension, diabetes, and prior colon resection for cancer at age 55. Examination reveals mild jaundice with vital signs of temperature 101.5°F, pulse rate 110/min, and BP 100/60 mmHg. She does not respond to verbal commands, but withdraws to pain. Abdominal examination reveals tenderness in the epigastrium and right upper quadrant. 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: C

  Common duct stones (choledocholithiasis) may be the cause of acute bile duct obstruction without warning, resulting in jaundice, pain, and sepsis. The sepsis may manifest as fever, hypotension, and altered mental status.

• Question 150:

  A75-year-old man is brought to the emergency department by his family for evaluation of jaundice. He complains of pruritus of 2 weeks' duration and a recent 10-lb weight loss. On examination, he is deeply jaundiced and has a nontender, globular mass in the right upper quadrant of the abdomen that moves with respiration. 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: F

  Pancreatic carcinoma occurs in the head of the gland in 75% of cases. About 75% of the patients with carcinoma in the head of the pancreas present with obstructive jaundice, weight loss, and, in the presence of advanced disease, abdominal pain.