USMLE USMLE Certifications USMLE Questions & Answers

• Question 561:

  A 35-year-old man comes to the physician because of pain and swelling of his right arm where he scraped it on a tree branch 2 days ago. His temperature is 38.3°C (101°F). Examination of the right forearm shows edema around a fluctuant erythematous lesion at the site of trauma. The area is extremely tender to palpation. Which of the following is most likely the primary mechanism of the development of edema in this patient?

  A. Degranulation of eosinophils

  B. Disruption of vascular basement membranes

  C. Increased hydrostatic pressure

  D. Release of thromboxane

  E. Separation of endothelial junctions

  Correct Answer: E

• Question 562:

  An investigator is studying the incidence of the common cold among medical students at various time points during the school year. Results show an increased incidence of upper respiratory tract infections among these students during finals week. It is hypothesized that the stress of studying for examinations adversely affects the immune system, making the students more susceptible to infection. Which of the following laboratory findings in these students during examination week is most likely to support this hypothesis?

  A. Decreased AM serum cortisol concentration

  B. Decreased macrophage activity

  C. Increased basophil count

  D. Increased lymphocyte count

  E. Increased natural killer cell activity

  Correct Answer: B

• Question 563:

  A 63-year-old man is brought to the emergency department because of a 4-day history of increasingly severe left leg pain and swelling of his left calf. He also has a 1-month history of increasingly severe upper midthoracic back pain. During this time, he has had a 9-kg (20-lb) weight loss despite no change in appetite. He has no history of major medical illness. His only medication is ibuprofen. He is 180 cm (5ft11in) tall and weighs 82 kg (180lb); BMI is 25 kg/m2. His vital signs are within normal limits. On examination, lower extremity pulses are palpable bilaterally. The remainder of the physical examination shows no abnormalities. An x-ray of the thoracic spine shows no abnormalities. A CT scan of the abdomen shows a 3-cm mass in the body of the pancreas; there are liver metastases and encasement of the superior mesenteric artery. Ultrasonography of the left lower extremity shows a femoropopliteal venous clot. Which of the following is the most likely cause of this patient's symptoms?

  A. Carcinoid syndrome

  B. Hypercoagulability from advanced malignancy

  C. Multiple endocrine neoplasia

  D. Splemic artery aneurysm and embolic disease of the left lower extremity

  E. Superior mesentric artery syndrome

  Correct Answer: B

• Question 564:

  A 26-year-old woman is brought to the emergency department 3 hours after ingesting approximately 50 tablets of aspirin in a suicide attempt. She is nauseated, confused, and sleepy. Her pulse is 130/min, respirations are 30/min, and blood pressure is 100/60 mmHg. Which of the following sets of laboratory values is most likely on evaluation of blood obtained before treatment?

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  E. Option E

  Correct Answer: B

• Question 565:

  A 62-year-old woman comes to the physician because of low back pain for 1 week. Menopause occurred 10 years ago. Physical examination shows localized tenderness over the lumbar spine after movement. X-rays of the spine show a compression fracture of L1-2. A DEXA scan shows decreased bone mineral density. Serum calcium and phosphorus concentrations and serum alkaline phosphatase activity are within the reference ranges. A bisphosphonate drug is prescribed. The expected beneficial effect of this drug is most likely due to which of the following actions?

  A. Decreased insulin-like growth factor-1 concentration

  B. Decreased osteoclast activity

  C. Decreased osteoprotegerin production

  D. Increased 1, 25- dihydroxycholecalciferol concentration

  E. Increased osteoblast actitvity

  F. Increased receptor activator of NF-kB ligand (RANKL) production

  Correct Answer: B

• Question 566:

  A 45-year-old woman with systemic sclerosis (scleroderma) comes to the physician because of a 3-week history of progressive shortness of breath and nonproductive cough. Her temperature is 36.9°C (98.4°F), pulse is 82/min, respirations are 20/min, and blood pressure is 136/85 mmHg. Crackles are heard in both lower lung fields. Pulmonary function tests show total lung capacity is 80% of predicted, and diffusing capacity for carbon monoxide, corrected for alveolar volume, is 65% of predicted. Histologic examination of a lung biopsy specimen is most likely to show which of the following findings?

  A. Diffuse interstitial fibrosis

  B. Intra-alveolar exudates

  C. Multiple thromboemboli

  D. Necrotizing vasculitis

  E. Non-necrotizing interstitial granulomas

  Correct Answer: A

• Question 567:

  A new blood test to detect prostate cancer is evaluated in 300 male volunteers. A needle biopsy of the prostate gland is done on all men with serum prostate-specific antigen concentrations greater than 5ng/mL (N < 4). One hundred men undergo biopsy procedures; 90 are found to have prostate cancer, and five are found to have chronic prostatitis. Which of the following is necessary to calculate the sensitivity of this test?

  A. Incidence of chronic prostatitis in the general population

  B. Number of men with test results greater than 5 ng/mL and a normal biopsy speciemen

  C. Prevalence of chronic prostatitis in the general population

  D. Prostate biopsies of men with test results equal to or below 5 ng/mL

  Correct Answer: D

• Question 568:

  A 26-year-old woman is brought to the emergency department because of an 8-hour history of severe back and abdominal pain and mild but persistent vaginal bleeding. Ultrasonography of the abdomen shows a 2-cm ectopic pregnancy in the ampulla. The ampulla has ruptured into the surrounding tissue. Fluid from this rupture will most likely be found in which of the following locations?

  A. Lesser peritoneal cavity

  B. Mesometrium

  C. Pouch of Douglas

  D. Uterine cavity

  E. Vagina

  Correct Answer: C

• Question 569:

  A 14-year-old girl has had nausea, intermittent diarrhea, and a 2.2-kg (5-lb) weight loss over the past 4 weeks. Examination shows a migrating serpiginous pruritic perianal rash. Her leukocyte count is 8000/mm3 with 20% eosinophils. Which of the following tests is most likely to yield an accurate diagnosis?

  A. Blood smear

  B. Bone marrow biopsy

  C. KOH preparation

  D. Microscopic examination of the stool

  E. Skin snip

  Correct Answer: D

• Question 570:

  A 40-year-old woman comes to the physician because of a 6-month history of increased facial hair growth. Her last menstrual period was 4 months ago. She is 165 cm (5 ft 5 in) tall and weighs 70 kg (154 lb); BMI is 26 kg/m2. Her pulse is 80/min, and blood pressure is 130/82 mm Hg. Physical examination shows temporal balding and coarse dark hair on the upper lip and chin. Pelvic examination shows clitoral enlargement. Her serum testosterone concentration is increased. Serum concentrations of androstenedione, dehydroepiandrosterone, and urinary 17-ketosteroids are within the reference ranges. Ultrasonography of the pelvis shows a 12-cm ovarian mass. Which of the following best describes this mass?

  A. Granulosa tumor

  B. Ovarian carcinoid

  C. Sertoli-Leydig tumor

  D. Teratoma

  E. Thecoma

  Correct Answer: C