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A 40-year-old African-American man is diagnosed with nephrotic syndrome due to collapsing glomerulopathy, a renal disease in which proteinuria is severe. Although he does not have heart failure, he does have pulmonary edema. Which of the following is likely involved in the mechanism of his pulmonary edema?
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d. Decreased oncotic pressure
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e. Pulmonary vein obstruction
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The most correct answer is d, decreased oncotic pressure.
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Though each of the options can be involved in the development of pulmonary edema, nephrotic syndrome can result in a reduction of plasma oncotic pressure, which normally serves as a force that moves fluid from the interstitium into the vascular system, counteracting the hydrostatic force of blood pressure. Lymphatic obstruction (answer a) can cause pulmonary edema but is unlikely in this patient. Liquid aspiration (answer b) and shock (answer c) can cause pulmonary edema through microvascular/alveolar injury, but both are unlikely in this patient. Pulmonary vein obstruction (answer e) can cause pulmonary edema due to an increase in hydrostatic pressure but is unlikely in this patient.
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A forensic pathologist performs an autopsy on an unidentified woman with an unknown medical history. She appears to be approximately 35-40 years old. The cut surface of the lung shows atheromata in pulmonary arteries. Which of the following was most likely present prior to the woman's death?
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a. Pulmonary hypertension
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b. Idiopathic pulmonary hemosiderosis
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c. Wegener's granulomatosis
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d. Goodpasture's syndrome
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e. Deep vein thrombosis in the lower extremity
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The most correct answer is a, pulmonary hypertension.
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In pulmonary hypertension, large arteries develop atheromata, mimicking systemic arteries in the setting of hypertension-related atherosclerosis. The presence of atherosclerosis in pulmonary arteries is nearly pathognomonic of pulmonary hypertension. Idiopathic pulmonary hemosiderosis (answer b), Wegener's granulomatosis (answer c), and Goodpasture syndrome (answer d) are all hemorrhagic lung diseases and would likely not be distinguishable on gross examination, especially in the absence of clinical information. Lower extremity deep vein thrombosis (answer e) is a risk factor for pulmonary thromboembolism, not pulmonary arterial atheromata.
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Three months after undergoing irradiation therapy for breast cancer, a 50-year-old woman develops fever and dyspnea. Chest radiograph shows infiltrates corresponding to the irradiation field. The clinician is considering a diagnosis of acute radiation pneumonitis but cannot exclude the possibility of infection. Consequently, a lung biopsy is performed, and a diagnosis of acute radiation pneumonitis is made by the pathologist. Which of the following was most likely present in the lung biopsy sample and useful to the pathologist in establishing the diagnosis?
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b. Perivascular lymphocytic inflammatory infiltrate
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c. Bronchiolitis obliterans
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d. Pulmonary hemorrhage and intra-alveolar siderophages
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e. Hyaline membranes and type 2 alveolar epithelial hyperplasia
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The most correct answer is e, hyaline membranes and type 2 alveolar epithelial hyperplasia.
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The morphology of acute radiation pneumonitis is diffuse alveolar damage often with type II pneumocyte hyperplasia and atypia; hyaline membranes are the hallmark of diffuse alveolar damage (Chap. 23). Interstitial fibrosis (answer a) typifies chronic radiation pneumonitis and is unlikely this soon following irradiation. Perivascular lymphocytic inflammatory infiltration (answer b) and bronchiolitis obliterans (answer c) are typical of acute and chronic (respectively) rejection of a pulmonary allograft. Pulmonary hemorrhage and intra-alveolar siderophages (answer d) are nonspecific findings and can be seen in any disorder with ongoing hemorrhage; such findings are not typical of acute radiation pneumonitis, and, even if present, would not help establish the diagnosis.