FIFTH EDITION ™ LANG E Q&A USMLE STEP 3 Donald A. Briscoe, MD Program Director, Methodist Hospital (Houston) Family Medicine Residency Medical Director, Denver Harbor Clinic Clinical Assistant Professor of Family Medicine in Medicine Weill Medical College of Cornell University Houston, Texas New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul Singapore Sydney Toronto Copyright © 2008 by The McGraw-Hill Companies, Inc. All rights reserved. Manufactured in the United States of America. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher. 0-07-164316-8 The material in this eBook also appears in the print version of this title: 0-07-149259-3. All trademarks are trademarks of their respective owners. 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For more information about this title, click here Contents Contributors ........................................................................................................................................................... v Introduction ......................................................................................................................................................... vii Acknowledgments .............................................................................................................................................. xv USMLE Step 3 Laboratory Values.................................................................................................................. xvii 1. Internal Medicine ........................................................................................................................................... 1 Questions .......................................................................................................................................................... 1 Answers and Explanations .......................................................................................................................... 53 Bibliography ................................................................................................................................................. 106 2. Surgery ......................................................................................................................................................... 109 Questions ....................................................................................................................................................... 109 Answers and Explanations ......................................................................................................................... 135 Bibliography.................................................................................................................................................. 162 3. Pediatrics ...................................................................................................................................................... 163 Questions ....................................................................................................................................................... 163 Answers and Explanations ......................................................................................................................... 182 Bibliography.................................................................................................................................................. 197 4. Obstetrics and Gynecology ....................................................................................................................... 199 Questions ....................................................................................................................................................... 199 Answers and Explanations ......................................................................................................................... 220 Bibliography.................................................................................................................................................. 241 5. Psychiatry ..................................................................................................................................................... 245 Questions ....................................................................................................................................................... 245 Answers and Explanations ......................................................................................................................... 264 Bibliography.................................................................................................................................................. 282 6. Preventive Medicine and Ethics............................................................................................................... 283 Questions ....................................................................................................................................................... 283 Answers and Explanations ......................................................................................................................... 301 Bibliography.................................................................................................................................................. 324 iii iv Contents 7. Pathology ...................................................................................................................................................... 327 Questions ....................................................................................................................................................... 327 Answers and Explanations ......................................................................................................................... 336 Bibliography.................................................................................................................................................. 343 8. Practice Test 1 ............................................................................................................................................... 345 Questions ....................................................................................................................................................... 345 Answers and Explanations ......................................................................................................................... 356 Bibliography.................................................................................................................................................. 368 9. Practice Test 2 ............................................................................................................................................... 369 Questions ....................................................................................................................................................... 369 Answers and Explanations ......................................................................................................................... 380 Bibliography.................................................................................................................................................. 390 10. Practice Test 3 ............................................................................................................................................... 391 Questions ....................................................................................................................................................... 391 Answers and Explanations ......................................................................................................................... 401 Bibliography .................................................................................................................................................. 411 11. Practice Test 4 ............................................................................................................................................... 413 Questions ....................................................................................................................................................... 413 Answers and Explanations ......................................................................................................................... 423 Bibliography.................................................................................................................................................. 433 Index ..................................................................................................................................................................... 435 Color insert appears after the Index. Contributors Douglas G. Adler, MD, FACG, FASGE Vanessa H. Gregg, MD Assistant Professor of Medicine Assistant Professor Director of Therapeutic Endoscopy Department of Obstetrics and Gynecology University of Utah, School of Medicine University of Virginia Health System Huntsman Cancer Center Charlottesville, Virginia Salt Lake City, Utah Kathie L. Hullfish, MD Brian K. Bednarski, MD University of Virginia Health System Department of Surgery Charlottesville, Virginia University of North Carolina School of Medicine Chapel Hill, North Carolina Philip C. Johnson, MD, FACP Professor and Director Sean M. Blitzstein, MD Division of General Medicine Director, Psychiatry Clerkship University of Texas Medical School at Houston Clinical Assistant Professor of Psychiatry Houston, Texas University of Illinois at Chicago Chicago, Illinois Maureen C. Kelley, PhD Assistant Professor Edison Catalano, MD Department of Pediatrics Medical Director, Laboratory Treuman Katz Center for Pediatric Bioethics Cooper University Hospital University of Washington School of Medicine Camden, New Jersey Seattle, Washington Christian A. Chisholm, MD H. J. Kim, MD Associate Professor Assistant Professor of Surgery Department of Obstetrics and Gynecology Division of Surgical Oncology University of Virginia School of Medicine University of North Carolina School of Medicine Charlottesville, Virginia Lineberger Comprehensive Cancer Center Chapel Hill, North Carolina Miguel A. Escobar, MD Assistant Professor Terry L. McDermott, MD Department of Pediatrics and Internal Medicine Resident University of Texas Health Science Center Methodist Hospital (Houston) Family Medicine at Houston Residency Houston, Texas Houston, Texas Christopher A. Greeley, MD, FAAP Susan M. Miller, MD, MPH Associate Professor of Pediatrics Faculty, Methodist Hospital (Houston) Family Division of Community and General Pediatrics Medicine Residency University of Texas Health Science Center Associate Professor of Clinical Medicine at Houston Weill Medical College of Cornell University Houston, Texas Houston, Texas v Copyright © 2008 by The McGraw-Hill Companies, Inc. Click here for terms of use. vi Contributors Seunghee Oh, MD Richard A. Rubin, MD Resident, Methodist Hospital (Houston) Family Associate Clinical Professor of Medicine and Medicine Residency Rheumatology Houston, Texas Baylor College of Medicine Clinical Chief of Rheumatology Philip R. Orlander, MD The Methodist Hospital Professor of Medicine Chief of Rheumatology Director, Division of Endocrinology, Diabetes, St. Lukes’s Episcopal Hospital and Metabolism Houston, Texas Assistant Dean for Curricular Affairs University of Texas Medical School at Houston Roland Schwarting, MD Houston, Texas Cooper University Hospital Camden, New Jersey John T. Patlan, MD Assistant Professor Leora J. Tesche, MD Department of General Internal Medicine Department of Surgery The University of Texas––MD Anderson Cancer Center University of North Carolina School of Medicine Houston, Texas Chapel Hill, North Carolina Anush S. Pillai, DO Faculty, Methodist Hospital (Houston) Family Medicine Residency Clinical Assistant Professor of Family Medicine in Medicine Weill Medical College of Cornell University Houston, Texas Introduction This book is designed for those preparing for the medical profession. The committees comprise rec- United States Medical Licensing Examination ognized experts in their fields, both academic and (USMLE) Step 3. It provides a comprehensive review nonacademic practitioners, as well as members of source with over 1000 “exam-type” multiple-choice state medical licensing boards. questions covering the clinical sciences. Detailed Step 3 is a two-day examination. You must com- explanations are provided for each question, with plete each day within 8 hours. The first day includes attempts to explain both why the correct answer is approximately 336 multiple-choice items divided correct and, when appropriate, why the incorrect into blocks of 48 items. Sixty minutes is allowed for answers are incorrect. In addition, the last section of completion of each block. There is a maximum of this book provides integrated, multispecialty prac- 7 hours of testing time and a minimum of 45 minutes tice tests, both to provide self-assessment and to of break time. There is also an optional 15-minute simulate the multiple-choice parts of the Step 3 tutorial. The amount of break time may be increased examination. by finishing the blocks or optional tutorial before the allowed time expires. Day 2 of testing includes approximately 144 multiple-choice items divided into blocks of 36 The United States Medical Licensing items. Forty-five minutes is allotted for each of these Examination, Step 3 blocks, with a total testing time of 3 hours for the completion of these blocks. The second day also Purpose of the Examination includes a Primum tutorial, for which 15 minutes is The purpose of Step 3 is to determine if a physician allowed. This is followed by 9 case simulations, for possesses and can apply the medical knowledge which 4 hours is allotted. There is an optional sur- and understanding of clinical science considered vey at the end of the second day, which can be com- essential for the unsupervised practice of medicine, pleted if time allows. A minimum of 45 minutes of with emphasis placed on patient management in break time is available on day 2. ambulatory care settings. The inclusion of Step 3 in The timing and structure of the testing days are the USMLE sequence of examinations ensures that subject to change without notice. Please refer to the attention is devoted to the importance of assessing USMLE web site (www.usmle.org) for the most up- the knowledge and skills of physicians who are to-date information. assuming independent responsibility for providing The principal organizing dimension for Step 3 general medical care to patients. design is the clinical encounter frame. The concept of frames encompasses several elements that are Examination Format critical to the definition of a physician-patient encounter. These elements include whether the prob- Step 3 consists of multiple-choice items and lem is new or on-going, the urgency of the need for computer-based simulations, distributed according intervention relative to the underlying problem, the to the content blueprint. The examination material chronology of events and the degree of familiarity is prepared by committees broadly representing the of the physician with the patient or the patient’s vii Copyright © 2008 by The McGraw-Hill Companies, Inc. Click here for terms of use. viii Introduction history. In addition, each encounter occurs in a spe- reviewed, and changed. After exiting a block, no fur- cific location. The primary encounter frames ther review of items or change of answers within that include initial workups, continuing care, and urgent block is possible. Policies regarding review of test interventions. items may be changed without notice. The most cur- The second organizing dimension is the physi- rent policies regarding review are posted on the cian task, which includes six categories: USMLE web site at www.usmle.org. The computer interface includes, among other features, clickable 1. Obtaining history and performing physical icons for marking questions for review, automated examination; review of marked and incomplete items, and a clock 2. Using laboratory and diagnostic studies; indicating the amount of time remaining. A tutorial on 3. Formulating the most likely diagnosis; using the computer interface is available at the 4. Evaluating the severity of the patient’s problems; USMLE web site. A 15-minute optional tutorial will be 5. Managing the patient (including health mainte- available for your use on the day of your examination. nance, interventions, therapeutics, applying legal Step 3 cases are intended to reflect the diversity and ethical principles); and of health care populations with respect to age, cul- 6. Applying basic science concepts (mechanisms). tural group, and occupation. The patient population Initial workup encounters are presentation of mix is intended to be representative of data collected new, acutely occurring problems among patients from various national databases that study health seen for the first time. Tasks emphasized include care in the United States. extensive data gathering and initial therapeutic interventions. Continuing care encounters are char- acterized by management of previously diagnosed Clinical Settings clinical problems among patients seen principally in ambulatory settings. Evaluating the severity of the problem(s) and prognosis, monitoring therapy and The expected outcome of USMLE Step 3 is an unre- long-term management are emphasized. Urgent stricted license to practice medicine without supervi- care encounters include life and/or organ- sion. Although you may have already begun special- threatening emergencies, usually occurring in the ist training, for this examination you are to assume emergency department or inpatient settings. the role of a general physician. You are a member of Physician tasks emphasized include rapid assess- an independent group practice associated with a ment of complex presentations and prompt thera- number of managed care plans. Your office has regu- peutic decision making. larly scheduled hours. You can admit patients to the The 2007 USMLE Bulletin of Information speci- 400-bed regional hospital, which provides care for fies that the clinical encounter frames will be broken both the urban and outlying rural communities. The down as follows: 20–30% initial care; 50–60% con- hospital provides standard diagnostic, radiologic, tinued care; 15–25% emergency care. The physician and therapeutic options, including ICUs and cardio- tasks will be broken down as follows: 8–12% obtain- thoracic surgery. There is a labor and delivery suite. ing history and performing physical examination; A fully equipped emergency department adjoins the 8–12% using laboratory and diagnostic studies; hospital, and medical evacuation helicopter service is 8–12% formulating most likely diagnosis; 8–12% available for transfer to a regional trauma center. You prognosis; 8–12% applying scientific concepts and do not have specialty-oriented hospital privileges but mechanisms of disease; 45–55% managing the may request specialist consultation. The table of nor- patient, which is broken down into 5–9% health mal laboratory values provided represents the normal maintenance, 18–22% clinical intervention, 12–16% values for the hospital. clinical therapeutics and 4–8% legal and ethical con- The multiple-choice items are organized into siderations. All of these percentages are subject to blocks that correspond to the clinical settings in change. The most up-to-date information is avail- which you will encounter the patients. Each setting able at the USMLE web site (www.usmle.org). is described at the beginning of its block. These During the allowed time for an individual block, descriptions are shown here as they would appear the questions may be answered in any order, during the examination.