Question 180
A 53-year-old male with a past medical history of hypertension for 15 years presents to the emergency room with complaints of a sharp tearing pain in his chest that radiates to his back. His admission blood pressure in the right arm is 171/100 mmHg and in the left arm is 137/80 mmHg. A chest x-ray reveals a widened mediastinum. Of the following, what is the most likely diagnosis?
A. Acute myocardial infarct with free wall rupture
B. Unstable angina
C. Hypertensive crisis
D. Aortic dissection
E. Pheochromocytoma
Answer for Question 180
Answer: D (Aortic dissection)
Explanation: The clinical scenario is characteristic for an aortic dissection, which often occurs in older males and is associated with hypertension as the main underlying risk factor. The pain is often described as sharp or tearing and can radiate to the back. Depending upon the location of the dissection in the arch, the left subclavian artery and not the right subclavian artery can be involved, leading to asymmetric pulses. Because there is blood in the wall of the aorta, the mediastinum can be widened on chest x-ray.
Question 181
A 55-year-old male with a past medical history of poorly controlled hypertension for 10 years presents to the emergency room with complaints of a sharp tearing pain in his chest that radiates to his back. His admission blood pressure in the right arm is 165/98 mmHg and in the left arm is 134/81 mmHg. A chest x-ray reveals a widened mediastinum. Of the following, histologic examination of the aorta would most likely reveal?
A. Extensive neutrophilic infiltration
B. Extensive granulomatous infiltration
C. Marked hemosiderin deposition
D. Marked lipofuscin deposition
E. Cystic medial degeneration
Answer for Question 181
Answer: E (Cystic medial degeneration)
Explanation: The clinical scenario is consistent with an aortic dissection, which is associated with hypertension as the main underlying risk factor. The pain is often described as sharp or tearing and can radiate to the back. Depending upon the location of the dissection in the arch, the left subclavian artery and not the right subclavian artery can be involved, leading to asymmetric pulses. Because there is blood in the wall of the aorta, the mediastinum can be widened on chest x-ray. Histologic examination of the aorta often reveals cystic medial degeneration. Neither marked hemosiderin deposition nor marked lipofuscin deposition normally occur in the aorta. While either Takayasu or giant cell arteritis can involve the aorta and would be associated with a granulomatous inflammation, neither is usually associated with a dissection, and both would be rare compared to an aortic dissection.
Question 182
A 63-year-old male with a known history of well-controlled hypertension that has been treated for 20 years dies in a motor vehicle accident after another driver runs a red light and strikes his vehicle. At the autopsy, which of the following pathologic findings is most likely to be identified by the pathologist?
A. Coarctation of the aorta
B. A nodule in the adrenal medulla
C. Retinal hemorrhages and papilledema
D. A pale eosinophilic acellular thickening of arterioles
E. A layered cellular proliferation of the wall of arterioles
Answer for Question 182
Answer: D (A pale eosinophilic acellular thickening of arterioles)
Explanation: The histologic change most frequently associated with essential hypertension is hyaline arteriolosclerosis, which can be described as a pale eosinophilic acellular thickening of the arterioles, due to accumulation of plasma proteins within the wall. Retinal hemorrhage and papilledema, and a layered cellular proliferation of the wall of arterioles (i.e., hyperplastic arteriolosclerosis) are associated with malignant hypertension, which the clinical scenario does not fit, as malignant hypertension follows a rapid course, whereas a 20 year history is best consistent with essential hypertension. While coarctation of the aorta and a pheochromocytoma (i.e., the nodule in the adrenal medulla) cause hypertension, secondary hypertension is much less common than essential hypertension; also, conditions causing secondary hypertension are often diagnosed because the hypertension does not respond to medical treatment.
Question 183
A 52-year-old male presents to the emergency room with a history of chest pain that began 2 hours ago. The pain has been unrelenting, and is associated with shortness of breath and nausea. Laboratory testing reveals an elevated troponin I and EKG reveals ST elevation in leads V3-V6. The pathologic process that was the cause of his symptoms originated in which of the following types of blood vessels?
A. Elastic
B. Muscular
C. Small arteries
D. Arterioles
E. Capillaries
Answer for Question 183
Answer: B (Muscular)
Explanation: The clinical scenario is consistent with an acute myocardial infarct. The most common cause of a myocardial infarct is atherosclerosis of the coronary arteries. The coronary arteries are a form of muscular artery.
Question 184
A 43-year-old male presents to the hospital with complaints of shortness of breath that has developed increasingly over the past year. Physical examination reveals bilateral crackles at the base of both lungs, but no murmurs or rubs. A chest x-ray reveals a bilateral pleural effusion at the lung bases. Laboratory testing reveals an elevated concentration of B-type natriuretic peptide. A CT scan of his trunk and head reveals a 3.5 cm mass at the left cerebral convexity. Surgical resection of the mass reveals it to be composed of an admixture of arteries and veins. Of the following, what was the mechanism for his presenting symptoms?
A. Cardiac metastases
B. Constrictive pericarditis
C. Focal bypass of capillaries
D. Childhood infection resulting in cardiac damage
E. Hypertensive due to increased intracranial pressure
Answer for Question 184
Answer: C (Focal bypass of capillaries)
Explanation: The clinical scenario is consistent with congestive heart failure, with relatively slow onset of dyspnea, bilateral pleural effusions, and an elevated BNP. The mass in the head is an arteriovenous malformation. In an arteriovenous malformation, there is an abnormal connection between arteries and veins, bypassing the capillaries. Blood flowing through the mass therefore does not serve to oxygenate tissue. The heart is doing extra work to pump this un-used blood, and it is possible for heart failure to develop (i.e., high output cardiac failure). The mass is benign, and not even a neoplasm, and so cardiac metastases would not occur. As there is no murmur, chronic rheumatic valvulitis is not very likely. With increased intracranial pressure, there should likely be symptoms such as headache, nausea, vomiting, and as the mass is a congenital malformation, it would not (without hemorrhaging) elicit increased intracranial pressure as the body has had enough time to adapt to its presence.