ObGy 4 - Answers v1 PDF

Exam Section : Item 1 of 50 National Board of Medical Examiners Mark Obstetrics and Gynecology Self-Assess...

Exam Section : Item 1 of 50 National Board of Medical Examiners Mark Obstetrics and Gynecology Self-Assessment X 1. A previously healthy 39-year-old woman at 37 weeks' gestation comes to the emergency department 2 hours after the onset of acute pain in the left hemithorax. She says that the pain is exacerbated by breathing. Her temperature is 38.2°C (100.8°F), pulse is 120/min, respirations are 24/min, and blood pressure is 110/70 mm Hg. Fetal heart tones are 170/min. Examination shows no abnormalities. An x-ray of the chest shows no abnormalities. An ECG shows nonspecific changes. Arterial blood gas analysis on room air shows: pH 7.43 Pco 2 35 mm Hg Po 2 70 mm Hg Which of the following is the most likely diagnosis? A) Angina pectoris B) Costochondritis C) Myocardial infarction D) Pulmona!Y embolus E) Viral pneumonia CorrectAnswer: D. This patient's presenting findings of acute onset dyspnea, pleuritic chest pain, tachycardia, tachypnea, and hypoxia are highly suggestive of a pulmonary embolus. A minority of patients with pulmonary embolism present with a mild fever, which can create diagnostic confusion. ECG commonly shows sinus tachycardia without ST segment depression or elevation. Pregnancy represents a hypercoagulable state, during which coagulation factors I, II, VII, VIII, IX and X are overexpressed, while the anticoagulant protein Sis under-expressed. Similarly, hormonal changes and compression by the gravid uterus lead to venous stasis and pooling of blood in the lower extremities and pelvis, common sites of venous thrombosis. Gravid patients are therefore at an increased risk for deep vein thrombosis and subsequent pulmonary embolism throughout pregnancy and in the postpartum period. Further evaluation should be performed to confirm the diagnosis; in the case of pregnancy, a ventilation-perfusion scan of the lung is preferred, though may be time-consuming and non-diagnostic. CT pulmonary angiography is rapid, sensitive, and specific, but it carries the risk for fetal radiation exposure. Incorrect Answers: A, B, C, and E. Angina pectoris (Choice A), when stable, is characterized by exertional or stress-triggered chest pain that improves with rest or nitroglycerin. It often radiates to the neck, jaw, or arm. Anginal chest pain does not typically change with respiration or position. Costochondritis (Choice B) involves inflammation of the costochondral or chondrosternal junctions of the thoracic rib cage. Costochondritis may present with symptoms that worsen during deep inspiration (caused by chest wall expansion during inspiration), however, localized tenderness to palpation helps to differentiate costochondritis from other causes of pleuritic chest pain. Costochondritis does not typically produce hypoxia. Myocardial infarction (Choice C) classically presents with acute-onset chest pain, radiating to the neck, jaw, or arm, along with shortness of breath, nausea, and/or lightheadedness. The pain associated with myocardial infarction is non-pleuritic. ECG typically shows ST segment depression or elevation. Viral pneumonia (Choice E) presents with dyspnea, cough, tachypnea, and fever, and may have associated pleuritic chest pain. The onset of symptoms occurs over hours or days, rather than suddenly. Chest x-rays may show lobar opacification or patchy, multifocal infiltrates. Given normal x-rays, this patient's presentation is more consistent with pulmonary embolism. Educational Objective: Pulmonary embolism presents with acute onset dyspnea, pleuritic chest pain, tachycardia, tachypnea, and hypoxia. Gravid patients are at an increased risk for deep venous thrombosis and pulmonary embolism caused by hypercoagulability and venous stasis. A high index of suspicion should be maintained for gravid patients who present with acute onset dyspnea, pleuritic chest pain, and hypoxia. 0 , ~ F' r , Next Score Report Lab Values Calculator Help Pause Exam Section : Item 2 of 50 National Board of Medical Examiners Mark Obstetrics and Gynecology Self-Assessment X 2. A 52-year-old woman comes to the physician for a routine examination. She has mild hypothyroidism well controlled with levothyroxine. Five years ago, she was diagnosed with stage I breast cancer; she completed tamoxifen therapy 1 year ago and is currently in remission. Menopause occurred 4 years ago. Her mother sustained a femoral fracture in a bicycle collision at the age of 55 years. The patient has smoked two cigarettes weekly for 25 years. She is 150 cm (4 ft 11 in) tall and weighs 43 kg (95 lb); BMI is 19 kg/m 2. Examination shows no thyromegaly. There is a small, well-healed surgical scar over the upper outer quadrant of the left breast. The remainder of the breast and pelvic examinations show no abnormalities. Which of the following historical findings is the greatest risk factor for osteoporotic fracture in this patient? A) BMI B) Family history of fracture C) Levothyroxine therapy D) Tamoxifen therapy E) Tobacco use Correct Answer: A. Osteoporosis occurs because of the loss of bone mineral density, most commonly appearing in elderly females of European descent. The condition results from the interplay of three mechanisms: failure to achieve peak bone density, increased bone resorption, and decreased new bone formation. The condition is often asymptomatic until a traumatic injury results in a fracture, most commonly involving the hip, distal radius, or vertebrae. The diagnosis of osteoporosis is made based on DEXA scan once the bone mineral density falls below 2.5 standard deviations of the mean for a young adult. Risk factors for osteoporosis are generally subdivided into nonmodifiable and modifiable categories, medical precipitants, and medication related. Low BMI is a key risk factor associated with osteoporosis. Bone remodeling and formation occurs in response to mechanical stress. Small stature, limited weight bearing exercise, frailty, and limited muscle strength are associated highly with low bone density. This patient is less than 5 feet tall, weighs less than 100 pounds, and has a BMI that is on the low end of normal, all of which suggest frailty as an overarching syndrome raising this patient's risk of an osteoporotic fragility fracture. Nonmodifiable risk factors for osteoporosis include age, gender, hormonal derangement, ethnicity, small stature, and family history. Select modifiable risk factors include excess alcohol consumption, vitamin D deficiency, malnutrition, inactivity, and limited physical strength training. Select medical disorders that increase the risk of osteoporosis include Cushing syndrome, hyperparathyroidism, hyperthyroidism, immobilization, hypogonadism, malabsorption syndromes, rheumatologic disorders, chronic kidney disease, multiple myeloma, and scoliosis. Select medications that increase the risk of osteoporosis include chronic glucocorticoid use, levothyroxine, and antiepileptic drugs. Incorrect Answers: B, C, D, and E. Family history of fracture (Choice B) in this patient may not relate to underlying osteoporosis, as it occurred in the setting of high-energy trauma on a bicycle. Levothyroxine therapy (Choice C) is associated with osteoporosis, but generally only when leading to subclinical hyperthyroidism. In this case, the patient's disease is described as well-controlled. Tamoxifen therapy (Choice D) is associated with preserved bone mineral density as it is an estrogen receptor agonist in bone. It is thus inversely correlated with osteoporosis, and selective estrogen receptor modulators (eg, raloxifene) may be used clinically in the prevention of osteoporosis. Tobacco use (Choice E) is associated with the development of osteoporosis. This patient has a minimal smoking history, making this aspect of her history less contributory than her frailty, low muscle mass, and short stature reflected in her BMI. Educational Objective: Osteoporosis occurs because of the loss of bone mineral density, most commonly appearing in elderly females of European descent. Low BMI is a key risk factor associated with osteoporosis. Bone remodeling and formation occurs in response to mechanical stress. Small stature, limited weight bearing exercise, frailty, and limited muscle strength are highly associated with low bone density. r " , ~ r-- r , Previous Next Score Report Lab Values Calculator Help Pause Exam Section : Item 3 of 50 National Board of Medical Examiners Mark Obstetrics and Gynecology Self-Assessment X 3. A 20-year-old woman comes to the physician because of a 1-week history of vaginal discharge. She is sexually active with one partner, and they use condoms inconsistently. She reports that he was recently treated for syphilis. Physical examination of the patient shows no abnormalities. Pelvic examination shows white verrucous lesions over the upper vaginal wall and cervix. A Pap smear is reported as atypical squamous cells. Human papillomavirus testing is negative for high-risk types. Which of the following is the most likely diagnosis? A) Bacterial vaginosis B) Cervical intraepithelial neoplasia (CIN) 2 C) Condylomata acuminata D) Herpes simplex E) Secondary syphilis Correct Answer: C. Condyloma acuminata are genital warts (soft, fleshy, verrucous growths) associated with human papillomavirus and can appear on the vagina, vulva, penis, and/or anal canal. The most commonly implicated strains of human papillomavirus are 6 and 11, which both have low oncogenic potential. High risk subtypes, including 16, 18, 31, and 33, may also be present and indicate a higher risk of progression to cervical dysplasia and malignancy. Diagnosis is made with examination and/or biopsy if necessary. The goal of treatment of condyloma acuminata is to destroy the affected cells and many methods can be used to achieve this. Topical formulations of podophyllotoxin, trichloroacetic acid, fluorouracil, or liquid nitrogen are potential agents. Immune therapy is also used, primarily with topical imiquimod, which stimulates the local innate immune system through toll-like receptors. Activation of the local immune system then leads to recognition of viral particles and an adaptive response is mounted. lncorrectAnswers:A, B, D, and E. Bacterial vaginosis (Choice A) is an infection caused by the overgrowth of bacteria in the vagina, most commonly Gardnerella vagina/is, usually in the setting of frequent sexual activity or antibiotic use, although it is not sexually transmitted. Symptoms include thin, malodorous, gray-white discharge. It does not cause verrucous papules to form. Cervical intraepithelial neoplasia (CIN) 2 (Choice B) is a moderate-grade cervical lesion with an increased risk of progression to cervical cancer. Cervical carcinoma is classically associated with infection from human papillomavirus high-risk strains 16, 18, 31, and 33, which are absent in this case. While visualization of the cervix via colposcopy can show areas of whitening when trichloroacetic acid is applied, verrucous lesions are not seen. Herpes simplex (Choice D) is a genital infection is most commonly caused by herpes simplex virus-2 and is characterized by painful vesicles in the genital area (eg, vulva, vagina, cervix, perineum). Infection typically begins with the formation of vesicles, which lyse and progress to shallow, painful ulcers with an erythematous border. Secondary syphilis (Choice E) presents with a scaly rash, classically involving the palms and soles, along with condyloma lata. Condyloma lata are typically whitish-gray, flat topped lesions, which differentiates them from the verrucous papules of condyloma acuminata. Educational Objective: Condyloma acuminata, or genital warts, are soft, verrucous papules caused by human papillomavirus strains 6 and 11. If present, high risk strains including 16, 18, 31, and 33 confer an increased risk of developing cervical dysplasia and carcinoma. r " , ~ r-- r , Previous Next Score Report Lab Values Calculator Help Pause Exam Section : Item 4 of 50 National Board of Medical Examiners Mark Obstetrics and Gynecology Self-Assessment X 4. A 25-year-old woman comes to the physician because of a 4-week history of right-sided pelvic pain. She has been sexually active with one partner for 3 years; they use condoms for contraception. Her last menstrual period was 3 weeks ago. She is afebrile. Pelvic examination shows a 12-cm, cystic, mobile, right adnexal mass. Her serum CA 125 concentration is 35 U/ml (N