Questions 246
A 62-year-old male is diagnosed with metastatic colonic adenocarcinoma, and, the following day, commits suicide with his handgun. The pathologist performing the autopsy identifies that the kidneys appear granular, not smooth. Histologic examination of the kidney reveals the finding illustrated in the image below. Of the following conditions, which is most likely described in this man’s past medical history.
A. Long-standing hypertension
B. Recent onset severe hypertension
C. Plasma cell neoplasm
D. Notation of a flank bruit
E. Ehlers-Danlos type IV
Answer for Question 246
Answer: A (Long-standing hypertension)
Explanation: At the arrows is hyaline arteriolosclerosis (i.e., an eosinophilic, acellular expansion of the vessel wall), which is associated with benign hypertension which would be consistent with a history of long-standing hypertension. Individuals with recent onset of severe hypertension, if they manifested changes in the arterioles, would have fibrinoid necrosis, or, hyperplastic arteriolosclerosis. While amyloidosis of the vessels can occur association with a plasma cell neoplasm, and the histologic appearance would be similar, this would be rare compared with vascular changes due to hypertension (or, diabetes mellitus, which also causes the development of hyaline arteriolosclerosis). A flank bruit can indicate stenosis of the renal artery, which occurs most commonly due to fibromuscular dysplasia or atherosclerosis, and which could lead to hypertension, but would be less common than hypertension as a cause, and the opposite kidney would be the gross and histologically affected one.
Question 247
A forensic pathologist is examining sections of a coronary artery from a man who died in a motor vehicle accident from blunt force injuries of the head and identifies the lesion illustrated in the image below. Of the following, which played the most significant role in developing the feature indicated by the star (i.e., just the region of the pale white-tan band)?
A. Smooth muscle cells
B. LDL receptor
C. Scavenger receptor
D. EBV receptor
E. Nicotinic acid receptor
Answer for Question 247
Answer: C (Scavenger receptor)
Explanation: The white star indicates the atheromatous core of the plaque, where there is accumulated intracellular and extracellular oxidized LDL. The oxidized LDL is taken up mostly by macrophages, using the scavenger receptor, not the LDL receptor. While smooth muscle cells can uptake lipid and form foam cells in the plaque, their contribution is less. The black arrow indicates the fibrous cap of the atheroma. The yellow area indicates the lumen of the vessel. There are aggregates of red blood cells in the lumen, but there is no thrombus.
Question 248
A pathologist is examining the heart from a 43-year-old male patient who died as the result of a self-inflicted gunshot wound. The only pathologic finding is illustrated below. Of the following, what was the most likely etiology?
A. Infection with cytomegalovirus
B. Age
C. Past rheumatic fever affecting the aortic valve
D. Systemic hypertension
E. Coronary artery disease
Answer for Question 248
Answer: D (Systemic hypertension)
Explanation: The enlarged cardiac myocyte nuclei indicate cardiac hypertrophy (compare the size of the nuclei at the two arrows), which would be caused by systemic hypertension. There is no good histologic evidence of recent or remote ischemic injury, such as fibrosis or coagulative necrosis (as would be seen with coronary artery disease). Chronic rheumatic aortic valvulitis can lead to aortic stenosis, but, it would be rare compared to systemic hypertension.
Question 249
A 52-year-old male is playing racquetball with a friend when he suddenly develops a sharp pain in his chest that radiates to his back. He informs his friend of his pain, but says that he thinks he pulled a muscle and he wants to continue playing; however, his friend takes him to the emergency room instead. If the image below illustrates the underlying cause of his clinical symptoms. Of the following, what would physical examination most likely reveal?
A. A fixed split S2
B. An S4
C. A crescendo-decrescendo systolic murmur
D. A decrescendo diastolic murmur
E. A mid-systolic click
F. An opening snap
Answer for Question 249
Answer: D (A decrescendo diastolic murmur).
Explanation: The man has an aortic dissection. The intimal tear is at the black arrow, and is located just above the aortic valve. An aortic dissection can involve the aortic valve annulus, leading to aortic insufficiency, which would be a decrescendo diastolic murmur.
Question 250
A forensic pathologist is examining the body of an individual who died suddenly and unexpectedly and identifies the pathologic finding illustrated in the image. Given that the right ventricle is not normally present at the apex of the heart and given that both sections in the image are from the same individual and are representative of the pathology, of the following, what was the most likely cause of death?
A. Metastatic carcinoma
B. Acute myocardial infarct
C. Pulmonary thromboembolus
D. Dilated cardiomyopathy
E. Hypertrophic cardiomyopathy
F. Arrhythmogenic right ventricular dysplasia
Answer for Question 250
Answer: C (Pulmonary thromboembolus).
Explanation: In the section at the left side of the image, the right ventricle is present (black arrow)–this is the apical section. No right ventricle should be present in this section; therefore, the right ventricle is markedly dilated. When the pulmonary artery is obstructed by a thromboembolus, it would put great strain on the heart and acute dilation would result. The left ventricle is not dilated; the interventricular septum is not hypertrophied out of proportion to the free wall; there is no fatty replacement of the right ventricle (see the right side image). There is no evidence of an acute myocardial infarct or metastatic neoplasm.
