4-1. The answer is c. (Greenberg, 2/e, pp 94-97. Hennekens, pp 206-208.) Intent-to-treat analysis, that is, including in the final results all the subjects who were initially randomized to receive either the drug or the placebo, is the preferred method of analysis for intervention studies. Although it may be tempting to include only those who complied with the medication, the results can be misleading. This study is a classic example of this pitfall. Indeed, the study showed that the difference in mortality between those who did and did not adhere to the placebo was even greater: 15% versus 28%. The difference persisted even after controlling for 40 different confounders. Thus, something related to compliance (with either the medication or the placebo) appeared to decrease mortality. Therefore, as a rule, remember that once randomization has been performed, all participants, regardless of their compliance, should be included in the results.

4-2. The answer is e. (Behrman, 16/e, p 1653. McMillan, 3/e, p 1558. Rudolph, 20/e, p 59.) Varicocele, a common condition seen after 10 years of age, occurs in about 15% of adult males. It results from the dilation of the pampiniform venous plexus (usually on the left side) due to valvular incompetence of the spermatic vein. Reduced sperm counts are possible with this condition; surgery may ultimately be indicated for infertility problems. Typically, these lesions are not painful but can become tender with strenuous exercise. Their typical "bag of worms" appearance on palpation makes diagnosis apparent in most cases. For a 16-year-old boy, reassurance and education seem appropriate.

4-3. The answer is c. (Fauci, 14/e, pp 803-804.) About half of all cases of nongonococcal urethritis are caused by Chlamydia trachomatis. Ureaplasma urealyticum and Trichomonas vaginalis are rarer causes of urethritis. Herpes simplex would present with vesicular lesions and pain. C. psittaci is the eti-ologic agent in psittacosis.

4-4. The answer is c. (Schwartz, 7/e, pp 95-96.) Transfusions with fresh frozen plasma (FFP) are given to replenish clotting factors. The effectiveness of the transfusion in maintaining hemostasis is dependent on the quantity of each factor delivered and its half-life. The half-life of the most stable clotting factor, factor VII, is 4 to 6 h. A reasonable transfusion scheme would be to give FFP on call to the operating room. This way the transfusion is complete prior to the incision with circulating factors to cover the operative and immediate postoperative period.

4-5. The answer is c. (Cameron, 4/e, pp 820-824.) Traumatic injuries to the diaphragm are associated with both blunt and penetrating trauma. The spleen, kidneys, intestines, and liver are the most frequently injured abdominal organs in blunt trauma; the diaphragm is the least. Missed injuries lead to problems with herniation and bowel strangulation with sufficient frequency that repair should not be delayed. All such injuries require repair once the diagnosis is made and the patient has been stabilized. Most acute defects in the diaphragm can be repaired via an abdominal approach, which allows exploration for coexisting injuries.

4-6. The answer is b. (Stobo, 23/e, pp 121-125.) The diagnosis in this patient is suggested by the physical exam findings. The findings of poor excursion, flatness of percussion, and decreased fremitus on the right side are all consistent with a right-sided pleural effusion. A large right-sided effusion may shift the trachea to the left. A pneumothorax should result in hyperresonance of the affected side. Atelectasis on the right side would shift the trachea to the right. A consolidated pneumonia would characteristically result in increased fremitus and would not cause tracheal deviation.

4-7. The answer is b. (LaDou, 2/e, pp 135-136.) Acute exposures to sound pressure levels above 180 dB result in traumatic rupture of the tympanic membrane and conductive hearing loss. The rupture should repair spontaneously unless infection occurs. If the loss persists for more than 3 mo, surgical repair is possible. Sensorineural loss is generally due to fractures or trauma to the inner ear. Mixed hearing loss can occur secondary to fractures of the temporal bone when both the middle and the inner ear are traumatized.

4-8. The answer is e. (Weir, pp 144-147.) The clinical picture suggests a saccular aneurysm that has become symptomatic by compressing structures about the base of the brain and subsequently leaking. Aneurysms enlarge with age and usually do not bleed until they are several millimeters across. Persons with intracerebral or subarachnoid hemorrhages before the age of 40 are more likely to have their hemorrhages because of arteriovenous malformations rather than aneurysms. Aneurysms occur with equal frequency in men and women below the age of 40, but in their 40s and 50s, women are more susceptible to symptomatic aneurysms. This is especially true of aneurysms that develop on the internal carotid on that segment of the artery that lies within the cavernous sinus. An angiogram is useful in establishing the site and character of the aneurysm. A computed tomography (CT) scan would be more likely to reveal subarachnoid, intra-ventricular, or intraparenchymal blood, but it would reveal the structure of an aneurysm only if it were several (more than 5) millimeters across. Magnetic resonance imaging (MRI) will reveal relatively large aneurysms if the system is calibrated and programmed to look at blood vessels. This patient had a transfemoral angiogram, a technique that involves the introduction of a catheter into the femoral artery; the catheter is threaded retrograde into the aorta and up into the carotid or other arteries of interest.

4-9. The answer is d. (Cunningham, 20/e, pp 607-615. DeCherney, 8/e, pp 316-319.) The incidence of ectopic pregnancy (outside the uterine cavity) is 1 in 100 pregnancies. Risk factors include previous history of pelvic inflammatory disease (PID) or ectopic pregnancy, use of an intrauterine device (IUD), diethylstilbestrol (DES) exposure, and prior pelvic surgery. Patients present with abdominal pain that may radiate to the shoulder (indicating irritation of the diaphragm from hemperitoneum), vaginal bleeding, cervical motion tenderness (CMT), and the presence of a boggy and poorly delineated pelvic mass 1 to 8 wk after a missed period. The patient may have other symptoms of pregnancy, such as nausea, vomiting, and breast tenderness. If the ectopic pregnancy ruptures, the patient may present with signs of shock. The Adler sign is the presence of "fixed" abdominal tenderness on turning the patient and may be seen in ectopic pregnancy. A ruptured corpus luteum cyst causes a tender ovary but no palpable mass. PID causes fever and bilateral lower quadrant pain and tenderness. Appendicitis is right-sided pain. Pelvic examination is typically normal in appendicitis and pyelonephritis.

4-10. The answer is b. (Tintinalli, 5/e, pp 1556-1559.) The patient has a peritonsillar abscess, which is an accumulation of pus between the tonsil-lar capsule and the superior constrictor muscle of the pharynx. Patients present with a "hot potato" voice, fever, cervical lymphadenopathy, trismus, and a displaced uvula due to a unilaterally enlarged tonsil. Patients complain of dysphagia, odynophagia, and otalgia. A retropharyngeal abscess is an infection of the deep spaces of the neck (from the base of the skull to the tracheal bifurcation); patients are often young children who present with fever, cervical lymphadenopathy, neck pain, neck swelling, torticollis (rotation to the affected side), difficulty breathing, and stridor. Patients with an exudative pharyngitis will have fever, cervical lym-phadenopathy, bilateral tonsillar enlargement, erythema, edema of the midline uvula, and discrete tonsillar exudate.

4-11. The answer is b. (Stobo, 23/e, pp 790-791.) A prostatic biopsy is necessary to confirm the diagnosis of prostatic carcinoma. A metastatic workup including bone scan would then follow. Bone scan is routinely used to evaluate for metastatic disease. Imaging of pelvic nodes by CT is unreliable because of lack of sensitivity. CT is also unable to reliably detect spread of prostatic cancer beyond the capsule.

4-12. The answer is c. (Greenfield, 2/e, p 1373.) Most clinicians would recommend aspiration and cytologic examination of the cyst fluid in this situation. Cysts are common lesions in the breasts of women in their thirties and forties; malignancies are relatively rare. All such lesions justify attention, however, and physicians must not underestimate the fear associated with the discovery of a mass in the breast, even in low-risk situations. If the lesion does not completely disappear after aspiration, excision is advised. In young women the breast parenchyma is dense, which limits the diagnostic value of mammography. The American Cancer Society (ACS) does not suggest a baseline mammographic examination until age 35 unless a suspicious lesion exists.

4-13. The answer is a. (Fitzpatrick, 3/e, pp 314-318, 332-335, 401-405, 877-882.) Erythema multiforme (EM) minor due to the herpes infection is the most likely diagnosis in this patient. The lesions of EM are classically target lesions; they are burning and pruritic. They are generalized and often involve the oral mucosa. Etiologies of EM major include drugs such as phenytoin, sulfonamides, barbiturates, and allopurinol. Finger pressure in the vicinity of a lesion in EM major leads to a sheetlike removal of the epidermis (Nikolsky sign). Pemphigus vulgaris is a chronic, bullous, autoimmune disease usually seen in middle-aged adults. The Nikolsky sign is positive in pemphigus vulgaris. Secondary syphilis appears 2 to 6 mo after primary infection and consists of round to oval maculopapular lesions 0.5 to 1.0 cm in diameter. The eruptions typically involve the palms and soles. Secondary syphilis lesions that are flat and soft with a predilection for the mouth, perineum, and perianal areas are called condylomata lata. The skin lesions of systemic lupus erythematosus (SLE) range from the classic butterfly malar rash to the discoid plaques of chronic cutaneous lupus erythe-matosus (CCLE). Urticaria is characterized by pruritic wheals typically lasting several hours.

4-14. The answer is a. (Adams, 6/e, pp 270-271.) The fact that vision is preserved excludes optic neuritis and cavernous sinus thrombosis. Optic neuritis produces pain in the affected eye and may be associated with a normal optic disc, but visual acuity should be deficient and an afferent pupillary defect should be apparent. Cavernous sinus thrombosis usually produces proptosis and pain, but impaired venous drainage from the eye should interfere with acuity, and the retina should appear profoundly disturbed. With a diphtheritic polyneuropathy, an ophthalmoplegia may develop, but this would not be limited to one eye and is not usually associated with facial trauma. Transverse sinus thrombosis may produce cere-brocortical dysfunction or stroke, but ophthalmoplegia would not be a manifestation of this problem.

4-15 through 4-16. The answers are 4-15 c, 4-16 c. (Behrman, 16/e, p 491. McMillan, 3/e, pp 164, 2122. Rudolph, 20/e, pp 214-215, 224,1939.) In a difficult delivery in which traction is applied to the head and neck, several injuries, including all those listed in the question, may occur. Erb-Duchenne paralysis affects the fifth and sixth cervical nerves; the affected arm cannot be abducted or externally rotated at the shoulder, and the forearm cannot be supinated. Injury to the seventh and eighth cervical and first thoracic nerves (Klumpke paralysis) results in palsy of the hand and also can produce Horner syndrome. Fractures in the upper limb are not associated with a characteristic posture, and passive movement usually elicits pain. Spinal injury causes complete paralysis below the level of injury.

When paralysis of an upper extremity from injury to the brachial plexus is found in a neonate, injury to the phrenic nerve should also be suspected because the nerve roots are close together and can be injured concurrently. The paralyzed diaphragm can be noted to remain elevated on a chest x-ray taken during deep inspiration, when it will contrast with the opposite normal diaphragm in its lower normal position, but on expiration this asymmetry cannot be seen. On inspiration, not only is breathing impaired since the paralyzed diaphragm does not contract, but the negative pressure generated by the intact diaphragm pulls the mediastinum toward the normal side, impairing ventilation further. The diagnosis can easily be made by fluoroscopy, where these characteristic movements on inspiration and expiration can be seen. Rarely, both diaphragms can be paralyzed, producing much more severe ventilatory impairment. Fortunately, these injuries frequently improve spontaneously.

4-17. The answer is a. (Stobo, 23/e, pp 298-302.) In primary hypothyroidism, autoimmune thyroiditis is the most common insult. Primary hypothyroidism can result from surgery or radiation therapy, but there is no such history in this patient. Thyroid cancer does not cause hypothy-roidism.

4-18. The answer is b. (Schwesinger, Am J Surg 172:411-417, 1996.) Heli-cobacter pylori infections have become extremely common. Nearly one-third of all American adults are now infected. Morphologically, the organism is a gram-negative, corkscrew-shaped, motile bacillus with three to seven flagella. Noninvasive approaches with simple, relatively inexpensive serologic and urea breath tests can establish the diagnosis of H. pylori infection. Culturing endoscopic scrapings or biopsy specimens has proved to be impractical because of the need for special media and elaborate growth conditions. A rapid urease test is used when endoscopy provides a specimen for analysis. Therapy is problematic because the organism is not easily eradicated. Monotherapy is largely ineffective. However, dual- and triple-drug therapy can achieve eradication in 80% to 90% of patients. Unfortunately, compliance rates with multidrug therapy are low.

4-19. The answer is c. (Seidel, 4/e, p 614.) At 20 wk of pregnancy, fundal height is at the level of the umbilicus. Part of the obstetrics and gynecology history should include GPAL (Georgia Power and Light): Gravida, Para, Abortions, and Living children.

4-20. The answer is c. (Chin, 17/e, pp 375-378.) Pertussis has been recognized with increased frequency in the United States among young adults and adolescents who were previously immunized. The immunity provided by the vaccine is limited and fades over time. The infection can be particularly severe in children under the age of 1. Antibiotic prophylaxis with erythromycin is recommended for all household and close contacts to prevent disease and outbreaks. The symptoms are not typical of influenza, legionellosis, or pneumonia due to streptococci. Prophylaxis of contacts is not recommended for mycoplasma infections; these are much less contagious than pertussis.

4-21. The answer is b. (Adams, 6/e, pp 1151-1154.) The slow evolution of gait difficulty, bladder dysfunction, paresthesias, hyporeflexia, impaired position and vibration sense, and anemia suggests combined systems disease, the neurologic equivalent of pernicious anemia. Persons with this disease may have a diet rich in vitamin B12, but if they lack intrinsic factor in the stomach, they will develop the deficiency. Patients usually acquire a megaloblastic anemia associated with the spastic paraparesis. Finding hypersegmented polymorphonuclear cells on the peripheral blood smear helps establish the diagnosis.

4-22. The answer is c. (Fauci, 14/e, p 1363-1364.) The history and physical are consistent with post-myocardial infarction syndrome (Dressler syndrome) rather than infection, pulmonary embolus, angina, or anxiety. This syndrome represents an autoimmune pleuritis, pneumonitis, or pericarditis, characterized by fever and pleuritic chest pain, with onset days to 6 wk post myocardial infarction. Therefore the most effective therapy is a nonsteroidal anti-inflammatory drug.

4-23. The answer is e. (Sadock, 7/e, p 2368.) This patient experienced an acute dystonic reaction, an adverse effect of neuroleptic medications secondary to blockage of dopamine receptors in the nigro-striatum system. Dystonic reactions are sustained spasmodic contractions of the muscles of the neck, trunk, tongue, face, and extraocular muscles. These can be quite painful and frightening. They usually occur within hours to 3 days after the beginning of the treatment and are more frequent in males and young people. They are also usually associated with high-potency neuroleptics. Occasionally dystonic reactions are seen in young people who ingest a neuroleptic medication, mistaking it for a drug of abuse.

4-24. The answer is b. (Wallace, 14/e, p 1054. USPSTF, 2/e, pp 568-569.) Folic acid use during the first trimester of pregnancy has been shown to decrease the incidence of neural tube defect, which is often associated with hydrocephalia, which in turn may be associated with intellectual disability that can be severe. In fact, folic acid supplements are recommended beginning 1 mo prior to conception for all women capable of becoming pregnant. It is advisable to counsel women to avoid alcohol during pregnancy, although the risk of fetal alcohol syndrome is increased with 14 drinks per week or more. The effect of lower levels of drinking has been inconsistent.

4-25. The answer is b. (Behrman, 16/e, pp 1469-1471. McMillan, 3/e, pp 1447-1448. Rudolph, 20/e, pp 1176-1180.) Iron-deficiency anemia is the most common nutritional deficiency in children between 9 and 15 mo of age. Low availability of dietary iron, impaired absorption of iron related to frequent infections, high requirements for iron for growth, and, occasionally, blood loss, all favor the development of iron deficiency in infants. A history regarding anemia in the family, blood loss, and gestational age and weight can help to establish the cause of an anemia. The strong likelihood is that anemia in a 1-year-old child is nutritional in origin, and its cause will be suggested by a detailed nutritional history.

Response to a therapeutic trial of iron is an appropriate and cost-effective method of diagnosing iron-deficiency anemia. A prompt reticulo-cytosis and rise in hemoglobin and hematocrit follow the administration of an oral preparation of ferrous sulfate. Intramuscular iron dextran should be reserved for situations in which compliance cannot be achieved. This is because this treatment is expensive, painful, and no more effective than oral iron. Dietary modifications, such as limiting the intake of cow's milk and including iron-fortified cereals along with a mixed diet, are appropriate long-term measures, but they will not make enough iron available to replenish iron stores. The gradual onset of iron-deficiency anemia enables a child to adapt to surprisingly low hemoglobin concentrations. Transfusion is rarely indicated unless a child becomes symptomatic or is further compromised by a superimposed infection. When the iron available for production of hemoglobin is limited, free protoporphyrins accumulate in the blood. Levels of erythrocyte protoporphyrin (EP) are also elevated in lead poisoning. Iron-deficiency anemia can be differentiated from lead intoxication by measuring blood lead, which should be less than 10 M-g/dL.

4-26. The answer is e. (Tintinalli, 5/e, pp 539-541.) The patient has a past medical history of appendectomy, which predisposes him to adhesions and small bowel obstruction (SBO). Other etiologies for SBO include incarcerated hernia, stricture, and malignancy. The high-pitched bowel sounds, the peristaltic rushes, and the tympany with percussion are physical findings when air is under pressure in viscera and intestinal fluid is present (i.e., obstruction). The hallmarks of intestinal obstruction are abdominal pain, distension, vomiting, and obstipation. Abdominal radiographs may reveal dilated loops of bowel in a ladderlike pattern and air-fluid levels. Large bowel obstruction (LBO) is due to malignancy, diverticulitis, and volvulus. A mnemonic for abdominal distension is the 6 Fs: Fat, Fluid, Food, Fetus, Feces, and Flatus.

4-27 through 4-28. The answers are 4-27 b, 4-28 c. (Hoskins, 2/e, pp 793-794, 802-803.) Microinvasive carcinoma of the cervix includes lesions within 3 mm of the base of the epithelium, with no confluent tongues or lymphatic or vascular invasion. The overall incidence of metastases from 751 reported cases is 1.2%. Simple hysterectomy is accepted therapy.

4-29. The answer is c. (Fauci, 14/e, pp 1352-1353, 1361, 1374.) Myocardial infarction occurs when an atherosclerotic plaque ruptures or ulcerates. Patients having myocardial infarctions are typically anxious, restless, and uncomfortable secondary to the extreme pain. They may demonstrate the Levine sign (clenching of the fist to demonstrate the severity of the pain). Risk factors for this patient include male gender, positive family history, hypertension, diabetes mellitus, tobacco use, and hyperlipidemia. Electrocardiogram (ECG) will show ST elevations, and cardiac isoenzymes [troponin, creatine phosphokinase (CPK)-MB fraction, and lactate dehydrogenase (LDH)] will be elevated. Patients with Prinzmetal's angina have recurrent attacks of chest pain at rest or while asleep (unstable angina) due to a focal spasm of an epicardial coronary artery. The diagnosis is confirmed by detecting the spasm after provocation during coronary arteriog-raphy. Cardiogenic shock is a form of severe left ventricular heart failure; patients are typically hypotensive. Right ventricular infarction is a compli cation of inferoposterior myocardial infarction. Patients present with jugular venous distension (JVD), the Kussmaul sign, and hypotension. Diagnosis is made by a right-sided electrocardiogram in which the leads are placed to the right of the sternum instead of the left.

4-30. The answer is e. (Fauci, 14/e, pp 2227-2230.) Primary hyper-parathyroidism is the most common cause of hypercalcemia in the outpatient setting. It is seen more frequently in women than men and is usually due to one parathyroid adenoma (usually in the inferior lobe). Patients often have a history of hypophosphatemia, fatigue, hypertension, depression, peptic ulcer disease, pancreatitis, bone pain, hypercalciuria, and nephrolithiasis from calcium oxalate stones. The most common cause of hypercalcemia in hospitalized patients is malignancy (i.e., breast, lung, multiple myeloma, head and neck, and renal cell) due to the secretion of parathyroid hormone-related peptide (PTHrp). Patients with familial hypocalciuric hypercalcemia (FHH) have hypocalciuria, a positive family history, and no end organ damage. Other causes of hypercalcemia include sarcoidosis, mycobacteria, milk-alkali syndrome, and medications (i.e., thiazide diuretics). Osteitis fibrosa cystica (replacement by fibrous tissue) is the bone abnormality seen with hyperparathyroidism.

4-31. The answer is d. (Greenfield, 2/e, pp 2231-2242.) The survival of patients with malignant melanoma correlates with the depth of invasion (Clark) and the thickness of the lesion (Breslow). It is widely held that patients with thin lesions (<0.76 mm) and Clark's level I and II lesions are adequately managed by wide local excision. The incidence of nodal metastases rises with increasing Clark's level of invasion such that a level IV lesion has a 30% to 50% incidence of nodal metastases. The assumption that removal of microscopic foci of disease is beneficial, in conjunction with retrospective data indicating improved survival in patients who have undergone removal of clinically negative but pathologically positive nodes, has led to the widely held belief that prophylactic node dissections are indicated for melanoma. Prospective data has challenged this concept. Veronesi and Sim have found that patients who underwent prophylactic node dissections survived no longer than those who were followed closely and underwent node dissections only after nodes became palpable. The subject remains controversial and further study and follow-up are necessary. Immunotherapy has not been successful in controlling widespread metastatic melanoma even when added to chemotherapy. Intralesional administration of bacille Calmette-Guerin (BCG) has been demonstrated to control local skin lesions in only 20% of patients. Dinitrochlorobenzene (DNCB) can also be used.

4-32. The answer is a. (Behrman, 16/e, pp 1365-1366, 1369-1371, 1383-1390. McMillan, 3/e, pp 287, 1329-1332, 1346-1350, 1354-1357, 1378-1380. Rudolph, 20/e, pp 1466-1469, 1474-1475, 1497-1502.) Most commonly, children with atrial septal defect (ASD) are asymptomatic, with the lesion found during a routine examination. In older children, exercise intolerance can be noted if the lesion is of significant size. On examination, the pulses are normal, a right ventricular systolic lift at the left sternal border is palpable, and a fixed splitting of the second heart sound is audible. For lesser degrees of ASD, surgical treatment is more controversial. Ventricular septal defect commonly presents as a harsh or blowing holosystolic murmur best heard along the left lower sternum, often with radiation throughout the precordium. Tricuspid regurgitation is a mid-diastolic rumble at the lower left sternal border. Often, a history of birth asphyxia or findings of other cardiac lesions are present. Tetralogy of Fallot is a very common form of congenital heart disease. The four abnormalities include right ventricular outflow obstruction, ventricular septal defect, dextroposi-tion of the aorta, and right ventricular hypertrophy. The cyanosis presents in infants and young children. Mitral valve prolapse occurs with the billowing into the atria of one or both mitral valve leaflets at the end of systole. It is a congenital abnormality that frequently only manifests during adolescence or later, is more common in girls than in boys, and seems to be inherited in an autosomal dominant fashion. On clinical examination, an apical murmur is noted late in systole, which can be preceded by a midsys-tolic click. The diagnosis is confirmed with an echocardiogram that shows prolapse of the mitral leaflets during mid to late systole. Antibiotic prophylaxis is recommended for dental work (especially if a murmur is present) as the incidence of endocarditis can be higher in these patients.

4-33. The answer is c. (Greenberg, 2/e, pp 2-22. Rosner, 5/e, pp 713-716.) This is an example of the Kaplan-Meier method, also called the product-limit method, of estimating survival. This technique takes into consideration that not all individuals may be followed until they experience the end-point or "failure" (in this example, death). Some may be lost to follow-

up prior to failure (they may move away, refuse to continue to participte any longer, etc.), and others who have not experienced an end-point may not have been followed for the whole observation period because they entered late in the course of the study. These are called censored observations (incomplete observations of a time to failure). Kaplan-Meier curves appear like uneven steps. Other methods can be used (actuarial method), but the Kaplan-Meier method is the most frequently employed.

4-34. The answer is e. (Berg, pp 681-682.) This man has signs of cerebellar dysfunction. That the deficit has been slowly progressive and is not associated with cognitive dysfunction makes it especially likely that a structural lesion in the posterior fossa is responsible for the deficit. Because the lesion need not disturb the external shape of the cerebellum, a posterior fossa myelogram will not necessarily yield an answer. The CT scan will show if there is an intraparenchymal or extraparenchymal lesion. Drug abuse is not likely to be a factor in this cerebellar syndrome because all the phenomena observed on examination are coordination problems, rather than combined cognitive and motor functions.

4-35. The answer is c. (Berg, pp 681-682.) The association of erythrocy-tosis with cerebellar signs, microscopic hematuria, and hepatospleno-megaly suggests von Hippel-Lindau syndrome. This hereditary disorder is characterized by polycystic liver disease, polycystic kidney disease, retinal angiomas (telangiectasias), and cerebellar tumors. This is an autosomal dominant inherited disorder with variable penetrance. Men are more commonly affected than women. Although neoplastic cysts may develop in the cerebellum in persons with von Hippel-Lindau syndrome, these usually do not become sufficiently large to cause an obstructive hydrocephalus. Other abnormalities that occur with this syndrome include adenomas in many organs. Hemangiomas may be evident in the bones, adrenals, and ovaries. Hemangioblastomas may develop in the spinal cord or brainstem as well as in the cerebellum. This syndrome is not associated with acoustic schwannomas that could cause bilateral hearing loss and is not accompanied by peripheral neuropathy, which could cause diffuse hyporeflexia.

4-36. The answer is a. (Berg, pp 681-682.) The cystic lesion and the other cerebellar lesions are most likely hemangioblastomas. These heman-gioblastomas often bleed and produce potentially lethal intracranial hematomas. Radiation therapy and needle biopsies would increase the risk of bleeding. Rather than spontaneously involuting, these lesions generally enlarge and become more unstable as time passes. Intracerebellar hemorrhage is increasingly likely as time passes.

4-37. The answer is d. (Berg, pp 681-682.) von Hippel-Lindau syndrome is associated with a high incidence of renal carcinomas. These malignant renal tumors usually develop years after the cerebellar hemangioblastomas, liver disease, or polycystic renal disease become symptomatic. People surviving intracranial hemorrhages caused by the intracerebellar hemangioblas-tomas often succumb to metastatic renal carcinoma. Treating the intracranial lesions does nothing to reduce the risk of metastatic renal cancer.

4-38. The answer is c. (Tierney, 39/e, pp 892-913.) Anasarca is generalized body edema that is often seen in the nephrotic syndrome. The grape clusters (lipid deposits or oval fat bodies in sloughed tubular epithelial cells) that appear under light microscopy appear as Maltese crosses under the polarized light. One-third of patients with nephrotic syndrome have a systemic disease (i.e., diabetes mellitus, SLE) and two-thirds have either (1) membranous nephropathy due to hepatitis C, SLE, syphilis, or medications; (2) minimal change disease; (3) focal glomerular sclerosis [human immunodeficiency virus (HIV) or heroin use]; or (4) membranoproliferative glomerulonephritis. Patients with glomerulonephritis present with a nephritic syndrome (hypertension, hematuria, and edema). Patients with acute interstitial nephritis from drugs or infection usually present with rash, arthralgias, eosinophiluria, and eosinophilia. Acute tubular necrosis (ATN) typically occurs after an insult, such as ischemia or exposure to a nephro-toxin (i.e., contrast media, paraproteins in multiple myeloma, antibiotics). Myoglobinuria is a consequence of rhabdomyolysis that leads to ATN.

4-39. The answer is c. (Mishell, 3/e, pp 1054-1055.) Though the estimated incidence of postpill amenorrhea is given as 0.7% to 0.8%, there is no evidence to support the idea that oral contraception causes amenorrhea. Eighty percent of women resume normal periods within 3 mo of ceasing use of the pill, and 95% to 98% resume normal ovulation within a year. If there were a true relationship between the pill and amenorrhea, one would expect an increase in infertility in the pill-using population. This has not been found. Infertility rates are the same for those who have used the pill and those who have not. Patients who have not resumed normal periods 12 mo after stopping use of the pill should be evaluated as any other patients with secondary amenorrhea. Women who have irregular menstrual periods are more likely to develop secondary amenorrhea whether they take the pill or not.

4-40. The answer is d. (Sadock, 7/e, pp 868.) Major depression can be the first manifestation of an occult carcinoma of the pancreas. The mechanism for this phenomenon is not known, although it may be due to humoral factors secreted by the tumor that act directly on the brain.

4-41 through 4-43. The answers are 4-41 c, 4-42 e, 4-43 a. (LaDou, 2/e, pp 142-148.) Heat stroke is characterized by the presence of mental status changes and a core body temperature of more than 39° C. Cardiovascular collapse will occur if the patient is not treated immediately, as the body temperature may reach 41.1° C. This is a medical emergency requiring intravenous hydration and rapid cooling: cool water or isopropyl alcohol 70% on the body with fanning, sponge baths, ice packs on the groin/axilla/neck and/or iced gastric lavage until the core body temperature drops to 39° C. Patients should be advised to avoid heat exposure for at least 4 wk because hypersensitivity to heat may persist for a long period of time after an episode of heat stroke. Heat cramps are characterized by painful muscle cramps along with some nausea and vomiting. The core body temperature is normal. This is caused by sodium depletion due to sweating: the patient should be placed in a cool environment and hydrated with a balanced salt solution. Rest for at least 1 to 3 days is recommended. Heat syncope is a sudden loss of consciousness due to vasodilatation secondary to heat. Heat exhaustion is what this patient is experiencing. She should be placed in a cool and shaded environment. This patient should also receive hydration and salt replenishment with intravenous fluids. Milder cases can be treated with oral hydration. At least 1 day of rest is recommended after heat exhaustion. Heat index guidelines are developed by the National Weather Service and predict risk of heat-related disorders based on ambient heat and humidity.

4-44. The answer is b. (Mishell, 3/e, pp 229-232.) In patients with abnormal bleeding who are not responding to standard therapy, a hys-teroscopy should be performed. The hysteroscopy can rule out endometrial polyps or small fibroids, which, if present, can be resected. In patients with heavy abnormal bleeding who no longer desire fertility, an endometrial ablation can be performed. If a patient has completed childbearing and is having significant abnormal bleeding, a hysteroscopy rather than a hysterectomy would still be the procedure of choice to rule out easily treated disease. Treatment with a gonadotropin-releasing hormone (GnRH) agonist would only temporarily relieve symptoms.

4-45. The answer is c. (Fauci, 14/e, pp 2057-2059.) Pheochromocytoma is a life-threatening disease if left undiagnosed. Patients present with episodic symptoms of headache, sweating, and palpitations. Pheochromocytoma may be associated with von Recklinghausen syndrome, neurofibromatosis, or von Hippel-Lindau syndrome. The diagnosis is made by 24-h urine for cate-cholamines and metanephrines. Ten percent of pheochromocytomas are bilateral and 10% are extra-adrenal. Increased levels of 5-HIAA are associated with carcinoid syndrome (facial flushing and diarrhea) from a tumor usually located in the lung or ileum. Patients with thyroid storm present with nausea, diarrhea, jaundice, fever, dyspnea, shortness of breath, diaphoresis, delirium, and tachycardia. The combination of diabetes mellitus, hypertension, obesity, insulin resistance, and dyslipidemia [increased very-low-density lipoproteins (VLDLs), increased triglycerides, and decreased high-density lipoproteins (HDLs)] is called syndrome X or CHAOS (Coronary artery disease, Hypertension, Atherosclerosis, Obesity, and Stroke).

4-46. The answer is b. (Fauci, 14/e, pp 1904-1906.) Ankylosing spondylitis (Marie-Strumpell arthritis) is a chronic and progressive inflammatory disease that most commonly affects spinal, sacroiliac, and hip joints. All patients have symptomatic sacroiliitis. Other symptoms may include uveitis and aortitis. Men in the third decade of life are most frequently affected, and there is a strong association with human leukocyte antigen (HLA)-B27 (90%) in white patients. Patients with advanced disease present with a bent-over posture. A positive Schober test indicates diminished anterior flexion of the lumbar spine. Involvement of the costovertebral joints limits chest expansion and eye involvement may cause an iritis. Patients with Reiter syndrome may present with a history of conjunctivitis, urethritis, arthritis, and enthesopathy (Achilles tendinitis).

4-47. The answer is c. (Hales, 3/e, p 351.) Severe anterograde memory deficits with an inability to form new memories are the main feature of Kor-sakoff syndrome or Alcohol Persisting Amnestic Disorder. Retrograde amnesia is also present, with the most severe loss of memory occurring for events that are closer to the beginning of the disorder. Remote memories are relatively preserved. The disorder is due to dietary thiamin deficiency and subsequent damage of the thiamin-dependent structures of the brain (mammillary bodies and the regions surrounding the third and fourth ventricle). Korsakoff syndrome can rarely be due to other causes of thiamin deficiency, such as diseases that cause severe malabsorption.

4-48. The answer is a. (Bradley, 3/e, pp 245, 741.) Meniere's disease is characterized by repeated brief episodes of fullness in the ear, tinnitus, hearing loss, and severe vertigo. The episodes may last hours to days. Attacks may be so severe as to cause the patient to fall to the ground due to severe dysequilibrium. The cause is generally idiopathic, but is thought to relate to distension of the semicircular canal and an increase in the volume of the endolymphatic fluid. For this reason, the condition has been called endolymphatic hydrops. Treatment is generally salt restriction and diuretics. Surgery with endolymphatic shunts is of unproven value.

4-49. The answer is a. (Behrman, 16/e, pp 505-506. McMillan, 3/e, pp 173-178. Rudolph, 20/e, pp 238-243.) Infants who are postmature (more than 42 wk of gestation) and show evidence of chronic placental insufficiency (low birth weight for gestational age and wasted appearance) have a higher-than-average chance of being asphyxiated, and passage of meco-nium into the amniotic fluid thus places these infants at risk for meconium aspiration. To prevent or minimize this risk, these infants should undergo immediate nasopharyngeal suction as their heads are delivered. Immediately after delivery and before initiation of respiration, their tracheas should be carefully and thoroughly suctioned through an endotracheal tube under direct vision with a laryngoscope. Afterward, appropriate resus-citative measures should be undertaken to establish adequate ventilation and circulation. Artificial ventilation performed before tracheal suction could force meconium into smaller airways.

4-50. The answer is b. (Stobo, 23/e, pp 430-438.) The most likely diagnosis in this patient is esophageal carcinoma. Dysphagia is progressive first for solids and then liquids. There is blood in the stool and a history of weight loss. The patient has alcohol use and cigarette smoking as risk factors. Prognosis is not good, because once there is trouble swallowing, there is significant esophageal narrowing and the disease is usually incurable. A barium contrast study should demonstrate an esophageal carcinoma with marked narrowing and an irregular, ragged mucosal pattern. Ninety percent of esophageal carcinoma is squamous cell; 10% is adenocarcinoma. Achalasia should not cause guaiac-positive stools or progressive symptoms.

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