A 37-year-old woman comes to the office due to left elbow discomfort and swelling for the past several days.  The patient recalls no major trauma but has been participating in a high-intensity workout program recently.  Physical examination findings are shown in the exhibit.  The patient is able to fully extend the elbow without increased pain.  Pathology involving which of the following structures is the most likely cause of this patient’s current condition?

An 85-year-old woman who worked as an environmental scientist prior to retiring comes to the office for evaluation of a round nodule on her left cheek.  Her only other medical condition is osteoarthritis.  Biopsy of the lesion shows nodular aggregates of dark-blue staining, basaloid keratinocytes in the dermis with peripheral palisading and cleft formation.  The cells are crowded, have scant cytoplasm, and have a high nucleus-to-cytoplasm ratio.  The patient refuses surgical resection of the lesion.  Which of the following is the most likely outcome?

The mother of a 2-year-old boy calls the office for guidance regarding his recent illness.  He has passed 4-6 stools daily over the last 2 days.  The feces are liquid and contain no blood or mucus.  His highest temperature reading at home was 37.8 C (100 F).  He is eating, drinking, and being playful as usual.  The patient has no prior medical problems and is up to date with vaccinations.  He recently began going to day care.  The mother is advised to bring the patient to the office for further evaluation.  While awaiting medical evaluation, which of the following oral fluids is most effective to prevent dehydration in this patient?

A clinical study compares several cut points for a new biomarker for bacterial bloodstream infection among adult patients in the intensive care unit (ICU) against blood culture results.  Analysis shows that a biomarker value ≥2.6 ng/mL has a sensitivity of 32% and a specificity of 96% for predicting bloodstream infections.  Which of the following conclusions about the study results is correct?

A 68-year-old male presents to your office complaining of difficulty urinating.  His past medical history is significant for prostate cancer treated with radiation therapy one year ago.  Ultrasonography reveals bilateral dilation of the ureters and renal calyces.  If related to the previous therapy, which of the following is the most likely cause of this patient’s current condition?

A 38-year-old woman comes to the office due to jaundice, nausea, and abdominal discomfort.  Vital signs are within normal limits.  Scleral icterus and hepatomegaly are present.  Laboratory results are as follows:

Anti–smooth muscle antibody titers are elevated.  Which of the following histologic findings is most likely to be seen on biopsy of this patient’s liver?

A 36-year-old man is brought to the hospital after being found wandering the streets barefoot and shouting to himself.  Although he takes antipsychotic medication daily, his parents are having difficulty managing him at home.  The patient believes he is fighting a conspiracy and that his thoughts are directly controlled by a device that was implanted in his brain during a prior hospitalization.  Previous trials of haloperidol, quetiapine, and risperidone resulted in minimal improvement.  He has no other medical problems.  On mental status examination, the patient is alert, and restless with poor grooming, disheveled clothing, and flat affect.  He refuses to answer most questions, accuses his parents of being part of the conspiracy, and mumbles nonsensical words.  Which of the following medications would be most effective for this patient’s illness?

A 63-year-old man comes to the office for follow-up of hypertension.  At his last appointment, he revealed that he had increased his intake of 12-oz cans of beer from 3 to 6 cans daily due to stress at work.  The physician advised him to seek help for his alcohol use because it could be causing his elevated blood pressure and has many negative health risks.  The patient now tells the physician, “I thought about what you said.  I know my alcohol use has gotten out of hand and is affecting my health.  My wife and daughter also say that I need to quit.  I have made an appointment with a counselor to talk about my options.”  Which of the following best describes this patient’s stage of behavioral change?

A 54-year-old man comes to the office due to concerns about having pancreatic cancer after a coworker died of the disease 6 months ago.  The patient has no epigastric pain, jaundice, or weight loss.  However, he worries constantly because in researching the illness he read that it may not have obvious symptoms in early stages and can be rapidly fatal.  The patient saw another physician 2 months ago, who performed a physical examination, laboratory evaluation, and abdominal CT scan.  The results were normal and the physician reassured the patient that he did not have cancer.  However, the patient reports that he has noticed occasional stomach noises after eating and would like to have additional testing done.  Which of the following is the most likely diagnosis?

A 37-year-old man comes to the office due to a rash.  For the last several months, he has had numerous small lesions on the hands.  The lesions are associated with occasional mild itching and bleed slightly if inadvertently struck against furniture or a wall.  Examination findings are as shown in the exhibit.  Which of the following is the most likely diagnosis?

A 3-month-old boy is brought to the office for follow-up due to a unilateral cleft lip and palate.  The patient has been doing well feeding with specialized bottle nipples and is gaining weight.  As part of his multidisciplinary care, the parents are told that he will need to be monitored for ear infections and hearing loss.  This is because the patient most likely has dysfunction of which of the following muscles?

A 44-year-old man comes to the office due to hand tremors.  The patient first noticed the tremor 2 years ago, and it has gradually worsened.  He feels well most of the time, but his hands shake uncontrollably with activities such as pouring drinks or writing notes.  The symptoms are most pronounced during stressful situations such as office meetings, and he keeps his hands tightly squeezed together or hidden below the table.  He has had no arm stiffness, leg symptoms, or difficulty walking, but his wife has noticed that the patient occasionally keeps nodding his head while talking.  Physical examination shows obvious tremors of outstretched hands that worsen during finger-nose testing.  Which of the following additional factors is most likely to be present in this patient’s medical history?

A 40-year-old woman comes to the office due to new-onset genital lesions.  On examination, she is found to have several genital warts in her vaginal area.  Testing for sexually transmitted infections is otherwise negative.  The patient admits to having a brief extramarital affair while traveling for business.  The following week, the physician receives a phone call from the patient’s husband, who is not a patient in the practice.  He knows his wife was recently seen and would like information regarding her health as he is concerned about his physical symptoms.  Which of the following would be the most appropriate response by the physician?

A 7-year-old boy is brought to the clinic for a well-child visit.  Over the past year, the patient has become fidgety, impulsive, inattentive, and restless, leading to a progressive decline in his grades.  Height and weight are at the 50th and 5th percentiles for his age, respectively.  The patient takes no medications or supplements.  The thyroid gland is diffusely enlarged to palpation without tenderness or bruit.  Neurologic examination reveals no focal findings.  Results of thyroid function tests are as follows:

Which of the following is the most likely etiology of this patient’s thyroid function test abnormalities?

A 58-year-old woman comes to the office due to a week of pain with swallowing.  Her symptoms have progressively worsened, and now she cannot eat comfortably.  The patient has a history of hypertension, osteoporosis, and primary biliary cholangitis progressing to cirrhosis.  She underwent a liver transplant 2 years ago and is on immunosuppressive therapy.  She does not use tobacco, alcohol, or illicit drugs.  Vital signs are within normal limits.  The oropharynx is normal in appearance.  Cardiopulmonary examination is unremarkable.  The patient has epigastric tenderness with no abdominal distension or guarding.  Upper endoscopy shows several small esophageal ulcerations with distinct borders located in the middle and lower portions of the esophagus.  A biopsy taken at the edge of an ulcer shows giant cells and intranuclear eosinophilic inclusions.  Which of the following is the most appropriate treatment for this patient?

A 66-year-old man is brought to the office by his daughter for medical evaluation.  The patient reports no chronic medical conditions but has not seen a physician for many years.  He takes no medications.  The patient is a retired veteran and recently relocated to live closer to his daughter.  He is an ex-smoker and does not use alcohol or illicit drugs.  Oxygen saturation on room air is 98%.  On physical examination, normal breath sounds are heard throughout both lungs.  Hand examination findings are shown in the exhibit.  The patient’s hand findings are most suggestive of which of the following underlying conditions?

An 80-year-old woman is evaluated for blisters that have developed on both feet over the past week.  The patient lives in a nursing home due to dementia but has no other chronic medical conditions and takes no medication.  Vital signs are within normal limits.  There are no oral lesions.  Examination findings are shown in the exhibit.  Which of the following is most likely involved in the pathogenesis of this patient’s condition?

A 24-year-old man is evaluated due to a syncopal episode that occurred immediately after he completed a 13-mile half-marathon.  The patient felt light-headed and then passed out.  He was immediately placed in a supine position and regained consciousness after 2-3 minutes.  The patient has no chest pain, palpitations, or shortness of breath.  He has never had a similar episode.  There is no family history of sudden death.  The patient does not use alcohol or illicit drugs.  Temperature is 37 C (98.6 F), blood pressure is 98/56 mm Hg, pulse is 80/min, and respirations are 14/min.  Complete physical examination and ECG show no abnormalities.  Which of the following is the most likely mechanism of this patient’s syncope?

A 38-year-old woman is admitted to the hospital overnight due to cellulitis.  The next morning, the hospitalist on service introduces herself to the patient and asks how she is feeling.  The patient angrily says, “It’s almost lunchtime, and I still haven’t gotten my breakfast.  How am I supposed to get better when you’re starving me?”  The patient has an order to receive a regular diet.  Which of the following is the most appropriate response by the physician?

A 19-year-old man is brought to the office by his mother due to uncharacteristic behaviors.  A year ago, the patient’s father died unexpectedly in a motor vehicle collision.  Afterward, the patient became increasingly withdrawn and stopped responding to his friends’ text messages.  He became disinterested in completing homework assignments and did not graduate from high school due to failing grades.  For the past few months, the patient has spent most of the time alone in his room, listening to music and drawing.  His mother says, “All of his drawings are of numbers in different colors and sizes.  He’s been fixated on the date and time that his dad died and thinks that they have special meanings.”  The patient is difficult to follow in conversation, changing topics frequently and making random remarks.  On mental status examination, he pauses before answering questions and provides brief, unrelated responses.  The patient does not make eye contact, and his affect is blunted.  He has no suicidal ideation or hallucinations.  Which of the following is the most likely diagnosis?

A 72-year-old man comes to the emergency department due to left-sided weakness and speech difficulty upon awakening this morning.  Medical history includes hypertension and persistent atrial fibrillation.  His anticoagulant medication was stopped 6 months ago after an episode of gastrointestinal bleeding.  Blood pressure is 160/90 mm Hg and pulse is 88/min and irregular.  Examination shows mild dysarthria, left lower facial weakness, and left hemiparesis.  CT scan of the head shows no evidence of intracranial bleeding.  Transthoracic echocardiogram shows left atrial enlargement, normal left ventricular systolic function, and mild mitral regurgitation.  The patient’s symptoms are determined to be caused by a thromboembolic event.  Which of the following is the most likely source of the thrombus?

A 25-year-old woman comes to the office due to a 4-week history of a pruritic skin rash.  The patient has no chronic medical conditions and takes no medication.  Vital signs are normal.  On examination, there are pink papules distributed symmetrically over the anterior surfaces of the shins and ankles.  Shave biopsy reveals prominent hyperkeratosis along with a thickened granular layer.  In addition, there is a bandlike infiltrate of mononuclear cells (predominantly lymphocytes) in the subjacent superficial dermis that involves the overlying epidermis.  The rete ridges have a sharpened, sawtooth appearance.  The basal layer of the epidermis is degenerated, with scattered colloid bodies.  Which of the following is the most likely diagnosis?

A 20-year-old woman comes to the emergency department due to bloody stools.  Approximately an hour ago, the patient had a bowel movement that appeared grossly bloody.  For the past month, she has also had decreased energy.  Temperature is 37 C (98.6 F), blood pressure is 110/60 mm Hg, pulse is 110/min, and respirations are 20/min.  The patient appears tired.  Cardiopulmonary examination reveals mild tachycardia.  The abdomen is soft without organomegaly.  Skin examination shows pallor and scattered bruises in various stages of healing throughout the trunk.  Complete blood count results are as follows:

Which of the following is the most likely cause of this patient’s condition?

A 49-year-old woman, gravida 2 para 2, comes to the office due to 10 months of irregular vaginal bleeding.  The patient’s last menstrual period was 3 years ago.  She has a history of hypothyroidism and takes levothyroxine daily.  Ultrasound reveals a thickened endometrium and a solid, left adnexal mass.  Endometrial biopsy reveals hyperplasia, and the patient is scheduled for laparotomy.  Intraoperatively, the ovarian mass is yellow and firm.  Microscopic examination of the mass shows small, cuboidal cells in sheets as well as in a microfollicular pattern with gland-like structures containing eosinophilic material.  Which of the following is most likely secreted by this patient’s tumor?

A 21-year-old woman, gravida 0, comes to the office due to postcoital bleeding.  She has been sexually active with her male partner for 6 months.  The patient has been taking birth control pills since age 15, when she first became sexually active.  The patient and her partner do not use condoms and have never been diagnosed with a sexually transmitted infection.  The patient smokes a pack of cigarettes per day.  Bimanual examination reveals a small mobile uterus and no cervical motion tenderness.  Speculum examination shows a well-estrogenized vagina without lesions.  The cervix has an area of erythema surrounding the external os and scant clear discharge.  She has her first Papanicolaou smear, and the cytological finding is shown in the image below.

Which of the following best describes the finding shown on this patient’s slide?

A 72-year-old woman comes to the emergency department due to bloody bowel movements.  One hour ago, the patient had a sudden urge to defecate and passed a large amount of bright red blood mixed with stool.  Several minutes later, she had another episode with a small amount of blood.  The patient reports no nausea, vomiting, abdominal pain, diarrhea, or fever and never had such symptoms before.  She is hospitalized but has no further bleeding.  Physical examination, including a digital rectal examination, is unremarkable.  A colonoscopy performed after bowel preparation reveals the findings in the exhibit.  There are no other abnormalities.  Which of following is the most likely source of this patient’s bleeding?

A 69-year-old man comes to the office due to a new growth on the left inner canthus for 3 months.  He has no significant medical conditions and takes no medications.  He owned a home construction business for 30 years.  The lesion is shown in the exhibit.  Examination shows no axillary or cervical lymphadenopathy.  This patient’s lesion most likely originated from which of the following?

A 78-year-old man is brought to the emergency department due to lightheadedness that began earlier in the day.  This morning, the patient felt unsteady and almost passed out when he tried to get out of bed.  He has not had similar symptoms before and he has had no chest pain or shortness of breath.  He has a history of coronary artery disease requiring percutaneous coronary intervention.  The rhythm strip of the ECG obtained in the emergency department is shown in the exhibit.  Which of the following is the most likely cause of this patient’s current symptoms?

A 54-year-old man comes to the physician for evaluation of exertional chest pain.  He first noticed the pain a couple months ago when he was shoveling snow off his driveway and has since experienced several episodes while doing other strenuous tasks.  He describes the pain as a heavy, crushing sensation and says it is relieved with rest.  The patient undergoes coronary angiography and is found to have severe stenosis of the right coronary artery and left anterior descending and circumflex arteries.  He is referred to a surgeon for coronary artery bypass grafting.  During the procedure, a portion of his great saphenous vein is removed and grafted to one of the diseased coronary arteries to bypass its atherosclerotic narrowing.  The vein used as a graft during this patient’s procedure can be accessed at which of the following sites?

A 52-year-old woman comes to the office due to worsening pain in her hands and ankles for the past several months.  She also has had a nonproductive cough, anorexia, and unintentional weight loss.  The patient has no prior medical conditions.  Physical examination shows digital clubbing and bony tenderness affecting the wrists, hands, and ankles.  There is localized right upper lung wheezing.  Chest x-ray reveals an irregular mass in the peripheral right lung.  Laboratory studies reveal mild normocytic anemia and normal serum electrolytes and calcium.  Which of the following is the most likely cause of this patient’s extremity pain?

A 35-year-old previously healthy woman comes to the hospital due to increasing shortness of breath and cough.  Over the past few months, she has had arthralgias, fatigue, low-grade fever, and weight loss.  Laboratory results are as follows:

CT scan of chest is shown in the exhibit.  Histologic examination of the lung would most likely reveal which of the following findings?

A 16-year-old boy is evaluated in the office due to leg cramps.  He plays soccer but frequently stops in the middle of practice due to cramps in both legs.  The patient is afebrile.  Blood pressure is 170/90 mm Hg bilaterally in upper extremities.  Point of maximal impulse is nondisplaced.  S1 is normal, and S2 is physiologically split.  An S4 is heard, as well as a continuous murmur best auscultated over the back at the left paravertebral area.  Distal pulses in the radial arteries are prominent.  Dorsalis pedis and posterior tibial pulses are difficult to palpate.  The rest of the physical examination is unremarkable.  Which of the following is the most likely cause of this patient’s continuous murmur?

A 75-year-old man is brought to the office for evaluation due to memory loss and increasing confusion for 6 months.  The patient is unable to manage his finances and occasionally gets lost in his neighborhood, needing to ask for directions.  On examination, he can recall only 1 of 3 objects after 5 minutes.  The patient performs poorly on cognitive assessment testing.  Cranial nerves and gait are normal.  T2-weighted MRI reveals multiple white matter abnormalities (hyperintensities) within the left frontal, bilateral parietal, and occipital white matter.  Also noted are subcortical gray matter hyperintensities in the bilateral thalamus.  Which of the following is the most likely diagnosis?

A 4-month-old girl is diagnosed with a febrile urinary tract infection.  A voiding cystourethrogram shows retrograde urine flow into the right ureter but no associated ureteral dilation.  One year later, a voiding cystourethrogram is repeated and shows no abnormalities.  Which of the following is the most likely cause of this infant’s presentation?