A 65-year-old woman is brought to the hospital due to progressive dyspnea and dry cough for 2 weeks. The patient was diagnosed with right breast cancer and completed radiation therapy 6 weeks ago. Temperature is 37.3 C (99.1 F), blood pressure is 115/70 mm Hg, pulse is 92/min, and respirations are 20/min. Oxygen saturation is 94% on room air. Examination reveals inspiratory crackles over the right lung anteriorly; the lungs are otherwise clear to auscultation. Chest radiograph shows ground-glass opacities in the right lung where radiation was delivered. Laboratory studies reveal no significant changes. Acute radiation-induced lung injury is suspected. Histopathologic examination would most likely reveal formation of which of the following?

Question

A 65-year-old woman is brought to the hospital due to progressive dyspnea and dry cough for 2 weeks.  The patient was diagnosed with right breast cancer and completed radiation therapy 6 weeks ago.  Temperature is 37.3 C (99.1 F), blood pressure is 115/70 mm Hg, pulse is 92/min, and respirations are 20/min.  Oxygen saturation is 94% on room air.  Examination reveals inspiratory crackles over the right lung anteriorly; the lungs are otherwise clear to auscultation.  Chest radiograph shows ground-glass opacities in the right lung where radiation was delivered.  Laboratory studies reveal no significant changes.  Acute radiation-induced lung injury is suspected.  Histopathologic examination would most likely reveal formation of which of the following?

Quizplus · Accepted Answer

Eductional Objective: Radiation-induced lung injury typically occurs following thoracic irradiation (eg, breast cancer), which damages pneumocytes and vascular endothelial cells and initiates an inflammatory response (eg, IL-1, TNFa, TGF-B).  This immune response can have both acute (eg, exudative alveolitis, hyaline membrane formation) and delayed (eg, dense fibrosis) effects that typically manifest with cough and dyspnea.

A 65-Year-Old Woman Is Brought to the Hospital Due to Progressive