Because Pathology Need Not Be the Root of All Suffering
The image is a microscopic section of the heart with an acute myocardial infarction. The cardiac myocytes have coagulative necrosis, with preservation of architecture but with loss of nuclear basophilia. Associated with the coagulative necrosis is a extensive neutrophilic infiltrate (see black arrows in image below).
The timing of the infarct would be around 2-3+ days.
Question 116
A 65-year-old male with a past medical history of hypertension, hyperlipidemia, and a 30 pack-year smoking history sustains an episode of chest pain while golfing with friends. He tells his friends that it feels like someone is standing on his chest and he clenches his fist in front of his chest when he does so. In addition to the pain, he is nauseous and sweating. They try to convince him to call an ambulance, but he refuses. The pain stops about 4 hours after it began. Three days later, his wife finds him dead in bed when she awakes. He had no complaints the night before. Of the following, which is most likely to be found at autopsy?
A. A ruptured ventricular aneurysm
B. A ruptured ventricular free wall
C. A ruptured interventricular septum
D. A ruptured papillary muscle
E. A ruptured coronary artery
Answer: B (a ruptured ventricular free wall).
Explanation: the symptoms are consistent with an acute coronary syndrome (i.e., pressure sensation in the chest associated with sweating and nausea). .He has several risk factors for coronary artery atherosclerosis, including his age, sex, and history of hypertension, hyperlipidemia, and smoking history. At three days, rupture of the myocardium can occur. The most common location is the free wall, which would lead to cardiac tamponade and a relatively quick death. Rupture of the interventricular septum and papillary muscle are much less common, and, while both are emergencies, the survival time would be expected to be longer and the patient would most likely be symptomatic. A ventricular aneurysm develops at >2 weeks after the myocardial infarct, and, because it is composed of scar tissue, does not commonly rupture. While a ruptured coronary artery could cause a hemopericardium and death, rupture of the coronary artery is not normally associated with an acute myocardial infarct.
Question 117
A 61-year-old male comes to the emergency room complaining of abdominal pain. He says that over the past 3 months, he has had abdominal pain which occurs 1-2 hours after eating, and then dissipates. Because of this pain, he has not wanted to eat, and has lost 20 lbs in that time frame. He has a 40 pack-year smoking history and hypertension. Of the following, what is the most likely diagnosis?
A. Acute mesenteric ischemia
B. Chronic mesenteric ischemia
C. Abdominal aortic aneurysm
D. Atypical acute myocardial infarct
E. Vasculitis
Answer: B (Chronic mesenteric ischemia)
Explanation: the history of abdominal pain occurring after eating a meal is characteristic of mesenteric ischemia. Because the disease process has been going on for some time, the best diagnosis would be chronic mesenteric ischemia. The pain occurs because atherosclerotic narrowing of the celiac artery or superior mesenteric artery or both blocks blood flow, and, when increased blood flow is needed to facilitate digestion, it does not develop and ischemia occurs. An abdominal aortic aneurysm can cause abdominal pain; however, not so consistently associated with meals. An atypical acute myocardial infarct should be considered when an older male (or female) with risk factors for atherosclerosis presents with abdominal pain, but the clinical presentation would be acute, nor chronic. Vasculitis can involve the celiac or mesenteric vessels; however, it would be much more rare than atherosclerosis.
Question 118
A 41-year-old male who has been diagnosed with hypertension for 2 years presents to his physician complaining of weakness, which he says comes and goes. Physical examination reveals a blood pressure of 152/81 mmHg, but is normal otherwise, including normal heart and lung sounds. Laboratory testing reveals an elevated concentration of sodium and a decreased concentration of potassium in the blood. A CT scan of the abdomen reveals a nodule in the right adrenal gland Additional laboratory testing would most likely reveal an elevated concentration of which of the following?
A. Aldosterone
B. ACTH
C. Epinephrine
D. Renin
E. Beta natriuretic peptide (BNP)
Answer: A (aldosterone)
Explanation: patients with an aldosterone-secreting adrenal adenoma (or, with adrenal cortical hyperplasia) can develop secondary hypertension. While patients can have only hypertension, they can also have hypernatremia and hypokalemia, which are associated with episodic weakness. In these individuals, laboratory testing would reveal an elevated concentration of aldosterone. Reninomas occur in the kidney and can be associated with hypertension. Pheochromocytomas occur as a nodule in the adrenal medulla and secrete catecholamines, but are not associated with hypernatremia or hypokalemia, and the hypertension and related symptoms are episodic. While Cushing syndrome is a cause of secondary hypertension, and with a pituitary adenoma, patients could have an increased concentration of ACTH, the patient has no other features of Cushing syndrome (e.g., thin skin, osteopenia, obesity, round facies).
QUESTION 113
A 67-year-old male with a past medical history of hypertension, hyperlipidemia, and a 30 pack-year smoking history is brought to the emergency room by ambulance, following an episode of chest pain occurring while golfing with friends, which started 6 hours ago. He describes the chest pain as though someone were standing on his chest and he clenches his fist in front of his chest when he does so. In addition to the pain, he is short of breath, nauseous, and sweating. He says that the pain extends to his left and right arm and jaw. His vital signs are BP of 164/96, heart rate of 104 bpm, and respiratory rate of 23 breaths per minute. Laboratory testing reveals an elevated troponin I upon admission. Of the following, which finding is most likely to be identified via physical examination?
A. A pleural rub
B. A pericardial friction rub
C. A systolic murmur
D. A diastolic murmur
E. Asymmetric pulses
Answer: C (a systolic murmur)
Explanation: the symptoms are consistent with an acute coronary syndrome (i.e., pressure sensation in the chest associated with sweating, nausea, and shortness of breath, and with the pain extending to the left arm, right arm, and jaw). The elevated troponin I indicates damage to the cardiac myocytes, which would be consistent with an acute myocardial infarct. With injury to the myocardium, papillary muscle dysfunction can occur, resulting in mitral insufficiency, which would be a systolic murmur. While a pericardial friction rub can occur in association with pericarditis due to an acute myocardial infarct, normally this requires at least around 1 day before it develops and would not be present at 6 hours.
QUESTION 114
A 51-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. The blood pressure in his right and left arm are 151/91 and 149/90 respectively. Physical examination reveals no murmur. A chest x-ray reveals a widened mediastinum. He is told he needs emergent surgery; however, he refuses and leaves against medical advice. Given that he survives without surgery, of the following, which is most likely to develop as a result of his presenting condition?
A. Coarctation of the aorta
B. False aneurysm
C. A dilated left ventricle of the heart
D. Berry aneurysm
E. True aneurysm
Answer: B (False aneurysm)
Explanation: the clinical scenario is consistent with an aortic dissection, which most commonly occur in the background of hypertension. The absence of a murmur indicates that the dissection did not extend to the heart, as if it had done so, it would most likely have caused aortic insufficiency. Given that he survived, the aortic dissection was contained, but would have, on image, appeared as a bulge in the wall of the vessel–therefore, it would be a false aneurysm. As the intima and most of the media are on the lumen side of the hemorrhage, a true aneurysm would not develop. An aortic dissection does not normally cause coarctation of the aorta, and, with no aortic insufficiency, if would not cause a dilated left ventricle of the heart. A berry aneurysm occurs in the brain, and hypertension will contribute to its development, but berry aneurysms are not associated otherwise with aortic dissection.
QUESTION 115
A 63-year-old male comes to the emergency room complaining of abdominal pain. He says that over the past 2 months, he has had abdominal pain which occurs 1-2 hours after eating, and then dissipates. Because of this pain, he has not wanted to eat, and has lost 15 lbs in that time frame. He has a 30 pack-year smoking history and hypertension. Of the following, what other disease process is most likely to be identified?
A. Metastatic lung carcinoma
B. Berry aneurysm
C. Pheochromocytoma
D. Peripheral vascular disease
E. Early onset Alzheimer’s disease
Answer: D (peripheral vascular disease)
Explanation: the history of abdominal pain occurring after eating a meal is characteristic of mesenteric ischemia. Because the disease process has been going on for some time, the best diagnosis would be chronic mesenteric ischemia. Chronic mesenteric ischemia is most commonly due to atherosclerosis of the celiac artery, superior mesenteric artery or both. As atherosclerosis is a systemic disorder, in patients with one form of atherosclerosis, another form can often be found; thus, in a person with chronic mesenteric ischemia, of the choices, peripheral vascular disease, which is also most commonly due to atherosclerosis, would be the one most likely to be identified.
QUESTION 109
A 64-year-old female is brought to the emergency room by her family. She developed a severe substernal chest discomfort 4 hours ago that was not relieved with antacids. In addition to the pain, she is nauseous and sweating. She says that the pain extends into her left and right arm. Her vital signs are BP of 161/92, heart rate of 102 bpm, and respiratory rate of 21 breaths per minute. Laboratory testing reveals a normal troponin I upon admission, and a repeat troponin I at 3 hours later is also normal. Of the following, what is the most likely diagnosis?
A. Stable angina
B. Unstable angina
C. Variant angina
D. non-ST elevation myocardial infarct
E. ST elevation myocardial infarct
Answer: B (unstable angina)
Explanation: given the acute presentation and with no past history of similar symptoms, stable angina would not be the most likely diagnosis. While the symptoms have been on-going for 4 hours, the laboratory testing reveals no elevation of troponin I (and with the laboratory testing repeated 3 hours later) so there is no evidence of cardiac myocyte injury, as troponin I should have risen by this time, and thus, a non-ST or ST elevation myocardial infarct are not likely. Unstable angina is one form of acute coronary syndrome.
QUESTION 110
A 67-year-old female with a past medical history of hyperlipidemia, diabetes mellitus type II and a 40 pack-year smoking history is brought to the emergency room by her family. She developed a severe substernal chest discomfort 6 hours ago that was not relieved with antacids, and was described as being like someone standing on her chest. In addition to the pain, she is nauseous, sweating, and short of breath. She says that the pain extends to her jaw. Her vital signs are BP of 155/93, heart rate of 101 bpm, and respiratory rate of 20 breaths per minute. Laboratory testing reveals an elevated troponin I upon admission. Of the following, what is the most likely diagnosis?
A. Stable angina
B. Unstable angina
C. Acute myocardial infarct
D. Aortic dissection
E. Angiosarcoma of the heart
Answer: C (acute myocardial infarct)
Explanation: the symptoms are consistent with an acute coronary syndrome, with a pressure-like pain in the chest, which is associated with nausea, sweating, and shortness of breath, and with risk factors for coronary artery atherosclerosis, including her age, and history of hyperlipidemia, diabetes mellitus type II, and smoking history. The elevated troponin I indicates injury to cardiac myocytes, which rules out stable angina and unstable angina. The most likely diagnosis is an acute myocardial infarct (a form of acute coronary syndrome). While an aortic dissection can cause an elevated troponin I, given the lack of a past history of hypertension, and the nature of the chest pain, an acute myocardial infarct is more likely than an aortic dissection. An angiosarcoma of the heart would be very rare.
QUESTION 111
A 65-year-old female with a past medical history of hypertension and a 40 pack-year smoking history is brought to the emergency room by ambulance. She had developed a severe substernal chest discomfort 2 hours ago that was not relieved with antacids, and was described as being like someone standing on her chest. In addition to the pain, she is sweating and short of breath. She says that the pain extends to both her left and right arm. Her vital signs are BP of 162/90, heart rate of 103 bpm, and respiratory rate of 21 breaths per minute. Laboratory testing reveals an elevated troponin I upon admission. She sustains a cardiac arrest while in the emergency room. Of the following, what would an autopsy most likely identify in the myocardium?
A. Rupture of the free wall
B. Rupture of the interventricular septum
C. A large soft yellow discoloration
D. A large firm white discoloration
E. Grossly normal cardiac muscle
Answer: E (Grossly normal cardiac muscle)
Explanation: the symptoms are consistent with an acute coronary syndrome (i.e., pressure sensation in the chest associated with sweating and shortness of breath, and with the pain extending to the left and right arm). The elevated troponin I indicates damage to the cardiac myocytes, which would be consistent with an acute myocardial infarct. Her cause of death was a cardiac dysrhythmia. Ruptures occur around 1-3 days. A large soft yellow discoloration would be an acute infarct, with the yellow representing coagulative necrosis and neutrophilic infiltrate; however, to see a well-developed acute myocardial infarct, the time since the pain began would be around 1 day at least. A large firm white discoloration would be a remote myocardial infarct, and would indicate an age of 2 months or more.
QUESTION 112
A 63-year-old female with a past medical history of diabetes mellitus type II, hyperlipidemia, and a 30 pack-year smoking history is brought to the emergency room by ambulance. She developed a severe substernal chest discomfort 4 hours ago while playing cards with friends. She described the pain as being like someone was standing on her chest. In addition to the pain, she is short of breath and sweating. She says that the pain extends to her left arm. Her vital signs are BP of 149/90, heart rate of 102 bpm, and respiratory rate of 21 breaths per minute. Laboratory testing reveals an elevated troponin I upon admission. Of the following, which is most likely to be present in a coronary artery?
A. An atheroma, with a thin fibrous cap, that produces 75% stenosis
B. An atheroma, with a thick fibrous cap, that produces 75% stenosis
C. Marked focal neutrophilic infiltrate of the wall associated with fibrinoid necrosis
D. Focal granulomatous inflammation
E. Hemorrhage into an atheroma with rupture and resultant thrombosis of the lumen
Answer: E (hemorrhage into an atheroma with rupture and resultant thrombosis of the lumen)
Explanation: the symptoms are consistent with an acute coronary syndrome (i.e., pressure sensation in the chest associated with sweating and shortness of breath, and with the pain extending to the left arm). The elevated troponin I indicates damage to the cardiac myocytes, which would be consistent with an acute myocardial infarct. An acute coronary syndrome is caused by an acute change within an atheromatous plaque, such as hemorrhage, thrombosis, or both. E. describes an acute change. A and B do not describe an acute change. Both A and B would be associated with stable angina. A. describes a vulnerable plaque, which would be predisposed to rupture, but, which, as described, is not consistent with an acute change. Both C and D, forms of vasculitis, could cause an acute myocardial infarct; however, compared to an acute plaque change occurring in the background of coronary artery atherosclerosis, vasculitis of the coronary arteries is a rare cause of an acute myocardial infarct.