USMLE USMLE Certifications USMLE-STEP-3 Questions & Answers

• Question 301:

  A 64-year-old White female presents to your office with complaints of vulvar pruritis and pain. You examine her and find an ulcerated lesion in the medial aspect of the left labia majora, 3.0 1.5 cm, that is thickened and indurated. You biopsy this lesion and the findings confirm a squamous cell carcinoma of the vulva. The groin nodes are palpably normal bilaterally. The next step in the patient's management would be which of the following?

  A. wide local excision of the lesion

  B. chemotherapy

  C. radiation therapy

  D. radical vulvectomy with ipsilateral inguinofemoral lymphadenectomy

  E. laser ablation

  Correct Answer: D Section: (none)

  Explanation:

  The management of vulvar cancer is primarily a surgical one. In the setting of small volume disease, wide local excision with 23 cm margins is generally sufficient. For patients to be candidates for such conservative management, the lesion must be <2 cm in width, <1 mm in depth, with no lymphatic or vascular space invasion and nonpalpable groin nodes. The majority of patients presenting with vulvar cancer, however, will require a radical vulvectomy and inguinofemoral lymphadenectomy to resect the primary lesion, as well as to evaluate for evidence of metastatic spread. If the lesion is midline, with a midline lesion defined as one less than 2 cm lateral to an imaginary vertical line drawn through the clitoris, urethra, and anal verge, the potential for metastatic spread to either groin is sufficiently high that both groins should undergo lymphadenectomy. If the lesion is lateralized, however, only the ipsilateral groin needs be dissected. If metastatic tumor is found in two or more groin nodes, postoperative radiation therapy to the involved groin(s) and ipsilateral pelvic nodes has been shown to improve survival.

• Question 302:

  A 62-year-old female with newly diagnosed International Federation of Gynecology and Obstetrics (FIGO) stage IIIC epithelial ovarian cancer is without evidence of visible remaining disease following a total abdominal hysterectomy, bilateral salpingo-oophorectomy, complete omentectomy, bilateral pelvic and paraaortic lymph node sampling, and rectosigmoid resection with reanastomosis. She is seen now for further treatment planning.

  The appropriate adjuvant therapy indicated in this setting is which of the following?

  A. external radiation

  B. the patient has no visible remaining disease and thus requires no further therapy

  C. implanted radiation seeds

  D. chemotherapy

  E. oral progestin

  Correct Answer: D Section: (none)

  Explanation:

  All patients diagnosed with ovarian cancer require postoperative chemotherapy, with the exception of FIGO stage IA and IB disease. There is some debate as to whether patients with stage IC disease require postoperative chemotherapy. Two large studies (ICON I, GOG 157) would suggest an improvement in overall survival among this group of patients when given postoperative chemotherapy following surgical debulking.

  For those patients requiring postoperative chemotherapy, the combination of carboplatin and paclitaxel represents the current standard. For several years, the combination of cisplatin and cyclophosphamide had been considered the treatment of choice. However, in 1993 a large prospective randomized trial compared cisplatin and cyclophosphamide to cisplatin and paclitaxel in patients with advanced stage disease and found the combination of cisplatin and paclitaxel to be associated with a 50% improvement in median survival. Though this came to be accepted as the new chemotherapeutic standard for the management of ovarian cancer, the nephrotoxicity and neurotoxicity associated with the cisplatin prompted a second large prospective randomized trial, GOG 158. This study compared the efficacy of cisplatin and paclitaxel to carboplatin and paclitaxel in patients with advanced stage disease following optimal surgical debulking. The study found the two arms to be equivalent and actually suggested that the carboplatin/paclitaxel arm may even be superior to the cisplatin/paclitaxel arm in terms of overall survival. This has since become the standard chemotherapeutic management for advanced stage ovarian cancer.

• Question 303:

  A 37-year-old multiparous White female, s/p bilateral tubal ligation, reports a family history remarkable for a mother diagnosed with bilateral breast cancer at the age of 43, from which she ultimately died, and a sister diagnosed with epithelial ovarian cancer at the age of 47, for which she is currently undergoing chemotherapy. Secondary to this worrisome family history, the patient elected to undergo genetic testing and was found to be a BRCA1 carrier.

  In view of her carrier status, you inform her of which of the following?

  A. She has a 3050% lifetime risk for the development of ovarian cancer.

  B. She has a 10% lifetime risk for the development of breast cancer.

  C. If she develops ovarian cancer, it will likely be 1015 years later than the normal onset of ovarian cancer seen in the general population.

  D. She is at increased risk for the development of hereditary nonpolyposis colorectal cancer (Lynch family syndrome type II).

  E. She has a lower risk for the development of Fallopian tube cancer than the general patient population.

  Correct Answer: A Section: (none)

  Explanation:

  Though 85% of cancers develop spontaneously, approximately1012% will arise in patients with an inherited chromosomal defect that places them at increased risk for the development of certain types of cancers. Patients with an inherited defect in a tumor suppressor gene encoded on chromosome 2, for example, have an increased risk for the development of breast, ovarian, endometrial, and ovarian cancers and suffer from a syndrome known as hereditary nonpolyposis colorectal cancer, or Lynch family syndrome type II. Patients with an inherited defect in a tumor suppressor gene encoded on chromosome 17 (BRCA1), on the other hand, have an increased lifetime risk for the development of predominantly breast and ovarian cancer. Patients with a BRCA1 chromosomal defect have a 3050% lifetime risk for the development of ovarian cancer (compared to a 1.4% lifetime risk in the general patient population), a 6080% lifetime risk for the development of breast cancer (compared to a 10% lifetime risk in the general patient), and an increased lifetime risk for the development of both Fallopian tube cancer as well as peritoneal carcinoma. These cancers generally arise in affected women 1015 years earlier than when seen in nonaffected women. The risk for ovarian and breast cancer in carrier women is sufficiently high to warrantbilateral salpingooophorectomy once childbearing is complete, or by the age of 35, whichever comes first, as well as prophylactic bilateral mastectomy. An alternative to prophylactic surgery is a more vigilant screening program, with lifetime annual mammography beginning at the age of 25 and ovarian screening with annual or biannual ultrasound, CA-125 determination, and pelvic examination beginning at the age of 35. The efficacy of these screening programs is unproven.

• Question 304:

  A27-year-old nulligravid single White female presents to your office for an annual examination. In taking her history, you learn that her mother died of ovarian cancer at the age of 63. There is no other family history ofbreast or ovarian cancer. The patient asks you to tell her what she can do to reduce her own ovarian cancer risk. What is the most effective strategy appropriate for this patient to reduce her risk?

  A. bilateral laparoscopic salpingooophorectomy

  B. daily aspirin use

  C. oral contraceptive therapy

  D. bilateral tubal ligation

  E. avoidance of breast-feeding following pregnancy

  Correct Answer: C Section: (none)

  Explanation:

  A meta-analysis of 20 studies published from 1970 to 1991 demonstrated a significant reduction in the risk of ovarian epithelial carcinoma with the use of oral contraceptives. The risk of ovarian cancer decreased with increasing duration of oral contraceptive use: a 1012% decrease in lifetime risk was noted with 1 year of use, a 50% decrease in lifetime risk noted with 5 years of use, and an 80% decrease in lifetime risk associated with 10 years of use. Oral contraceptive therapy has consistently demonstrated in epidemiologic studies the ability to decrease a woman's lifetime risk for the development of ovarian cancer. It is the most effective means of primary prevention in women at high risk for the development of ovarian cancer, short of physically removing the ovaries themselves. Both hysterectomy and bilateral tubal ligation have been associated with a 30% decrease in the lifetime risk for the development of ovarian cancer. However, in women yet to complete their childbearing neither is a realistic option. Breast-feeding and increasing parity have been shown to decrease a woman's lifetime risk for the development of ovarian cancer. There are some data to suggest that anti-inflammatory medications (aspirin, NSAID) may decrease the risk of ovarian cancer, but this has yet to be substantiated in epidemiologic studies.

• Question 305:

  The background of major congenital anomalies in a general obstetric population is closest to which of the following numbers?

  A. 0.1% (1 in 1000)

  B. 0.5% (5 in 1000)

  C. 1% (10 in 1000)

  D. 3% (30 in 1000)

  E. 7% (70 in 1000)

  Correct Answer: D Section: (none)

  Explanation:

  A major congenital anomaly is defined as one that is not compatible with survival or one that requires major corrective surgery to restore normal function. The risk of such anomalies in a general obstetric population is usually reported to be between 2 and 3%. If minor congenital anomalies are included, 7 10% of pregnancies will be affected.

• Question 306:

  Apatient presents to your office for an annual gynecologic examination. She is an obese, postmenopausal, White female who reports a 4-month history of vulvar pruritis. Otherwise, she is without complaint. On examination, she is noted to have a whitened plaque-like area involving the posterior fourchette. The area is nontender, raised, and approximately 2.0 2.0 0.5 cm.

  What is the next step in the management of this patient?

  A. Prescribe a topical antimonilial cream.

  B. Obtain a viral culture for herpes simplex type II.

  C. Perform a vaginal wet mount.

  D. Obtain a punch biopsy from the center of the lesion.

  E. Prescribe a topical steroid cream.

  Correct Answer: D Section: (none)

  Explanation:

  The most common presenting symptom of vulvar cancer is vulvar pruritis. Women diagnosed with vulvar cancer typically experience a 6-to 12-month delay prior to diagnosis secondary to the hesitancy of physicians to biopsy the area in the office in order to establish a histologic diagnosis. Generally, women are prescribed antimonilial creams to address presumed intertriginous yeast infections, or topical steroid creams to relieve the inflammation and associated pruritis. Ultimately, in the absence of improvement, a biopsy will finally be performed and the diagnosis established. Delay in diagnosis is the leading cause of preventable death in patients diagnosed with vulvar cancer, with the 5-year survival rate dropping off precipitously with advancing stage at diagnosis (stage I 90%, stage II 80%, stage III 50%, stage IV 15%). Physicians should have a very low threshold to biopsy cutaneous abnormalities noted on the external genitalia in any patient presenting for a problem visit, or for routine gynecologic care.

• Question 307:

  Which of the following maternal cardiac conditions is associated with the highest mortality rate during pregnancy?

  A. mitral stenosis, New York Heart Association class 12

  B. corrected tetralogy of Fallot

  C. porcine prosthetic heart valve

  D. mechanical prosthetic heart valve

  E. pulmonary hypertension

  Correct Answer: E Section: (none)

  Explanation:

  Many women with underlying cardiac disease have increased risk for serious complications during the pregnancy, including maternal mortality. Clark et al. have classified maternal cardiac conditions into mortality groups. Group 1 conditions (including mild mitral stenosis, corrected tetralogy of Fallot, and porcine prosthetic valves) have a maternal mortality rate of less than 1%. Group 2 conditions, which include mechanical prosthetic heart valves, more severe degrees of mitral stenosis, uncorrected congenital heart disease, and mild Marfan syndrome, have a mortality rate of 515%. Group 3 conditions include those that have a mortality risk of 50% or higher and include pulmonary hypertension, complicated coarctation of the aorta, and Marfan syndrome with an abnormal aortic root.

• Question 308:

  Which of the following statements regarding seizures in pregnancy is true?

  A. Women with a seizure disorder are at increased risk for eclampsia.

  B. Carbamazepine would be a better anticonvulsant during pregnancy, as it is associated with lower risk of congenital anomalies.

  C. Women who take valproate during pregnancy are at increased risk for both open neural defects and congenital heart disease.

  D. Women who require multidrug therapy to control their seizures are at no greater risk for congenital anomalies than women on monotherapy.

  E. It has been clearly demonstrated that women taking anticonvulsants benefit from higher doses of folic acid for prevention of neural tube defects.

  Correct Answer: C Section: (none)

  Explanation:

  All anticonvulsant drugs are associated with at least some risk of congenital abnormalities. Most anticonvulsants are classified as FDA category D, indicating that there is some demonstrated fetal risk but that the maternal benefits of taking the medication may outweigh the risks to the fetus. Carbamazepine, which for a time was thought to have a lower risk for fetal anomalies than other agents such as phenytoin, is now known to have a risk as high or higher. It particularly contributes to an increased risk when it is part of multidrug therapy for women with epilepsy. While the risk of neural tube defects is known to be elevated in women with epilepsy, and particularly those taking anticonvulsant drugs, no data exist to show that higher doses of folic acid will prevent neural tube defects in this group of women. The risk of open neural tube defects in women taking valproate is thought to be 1% (or 10 times the risk in the general population), and the risk of congenital heart disease is also increased.

• Question 309:

  A pregnant woman presents to the ER at 20 weeks' gestation with an acute exacerbation of her chronic bronchial asthma. She complains of a cold of 1 week's duration and admits that she lost her inhaler 2 weeks ago. Her examination reveals a temperature of 38 C, RR of 40, pulse of 110, and fetal heart rate of

  150. Her lung examination is notable for diffuse expiratory wheezes and a prolonged I:E ratio. She is utilizing accessory muscles for breathing, which appears labored.

  Which of the following statements regarding asthma in pregnancy is true?

  A. Asthma exacerbations are more common in pregnant women than in nonpregnant women of similar age.

  B. Influenza vaccination is contraindicated in pregnancy.

  C. Peak expiratory flow rate monitoring is unreliable for monitoring disease state during pregnancy.

  D. In pregnant women, the arterial partial pressure of carbon dioxide (PaCO2) is decreased on arterial blood gases compared to nonpregnant individuals.

  E. Due to potential risks of fetal radiation exposure, chest radiography should not be performed to evaluate for underlying pneumonia in women with asthma exacerbation.

  Correct Answer: D Section: (none)

  Explanation:

  Physiologic changes in respiration during pregnancy include reduced total lung capacity and functional residual capacity, increased inspiratory capacity and no change in the vital capacity. Increased progesterone causes a chronic hyperventilation, as reflected by a 3040% increase in tidal volume and minute ventilation. This rise in minute ventilation results in a decrease in both alveolar and arterial carbon dioxide, with normal arterial partial pressure of carbon dioxide in pregnancy ranging between 27 and 32 mmHg. Overall, the risk of asthma exacerbation is not thought to be higher in pregnancy. The peak expiratory flow rate correlates well with the forced expiratory volume in 1 second, which is an excellent way of monitoring disease state in both pregnant and nonpregnant individuals. The Centers for Disease Control recommends vaccination against influenza during the appropriate season for all pregnant women who will be in the second and third trimester during the time of vaccine administration. This is a killed virus vaccine and has not been demonstrated to be associated with risk to the developing fetus. Similarly, the pelvic radiation dose of a single chest radiograph is approximately 50 mrad, which is well below the threshold of concern for fetal risk of 5 rad.

• Question 310:

  Which of the following statements about diabetes in pregnancy is true?

  A. The risk of spontaneous abortion is not increased when compared to women without diabetes.

  B. The risk of congenital anomalies rises in relation to the maternal hemoglobin A1C.

  C. The rate of stillbirth is unchanged when compared with nondiabetic women.

  D. The risk of cesarean birth is unchanged when compared to nondiabetic women.

  E. Glycemic control is not related to fetal macrosomia.

  Correct Answer: B Section: (none)

  Explanation:

  Women with preexisting diabetes, both type 1 and type 2, are at increased risk both for spontaneous abortion and congenital anomalies, and the risk for these rises in direct relation to the maternal hemoglobin A1C concentration. In general, women with diabetes are at increased risk for late pregnancy complications, including stillbirth and cesarean delivery. The likelihood of fetal macrosomia (birth weight greater than 4000 g) increases with worsening degrees of maternal glycemic control; the macrosomic fetus is at increased risk for birth trauma, including shoulder dystocia and resultant Erb palsy.