A 44-year-old man arrives to the emergency department with a persistent cough and gradual weight loss. Over the last three months, he has shed 5 kg (11 lb). The patient just moved to the United States from Southeast Asia. The temperature is 37.4 degrees Celsius (99.3 degrees Fahrenheit), the blood pressure is 113/70 mm Hg, the pulse rate is 78 beats per minute, and the respirations rate is 18 / minute. An x-ray of the chest indicates an apical left lung infiltration. Gram stain and cultures on sputum are negative. A lung biopsy specimen culture, on the other hand, develops acid-fast bacilli. The lung specimen was microscopically examined. Which of the following processes is most likely to contribute to formation of the finding indicated by the arrow?

Question

A 44-year-old man arrives to the emergency department with a persistent cough and gradual weight loss. Over the last three months, he has shed 5 kg (11 lb). The patient just moved to the United States from Southeast Asia. The temperature is 37.4 degrees Celsius (99.3 degrees Fahrenheit), the blood pressure is 113/70 mm Hg, the pulse rate is 78 beats per minute, and the respirations rate is 18 / minute. An x-ray of the chest indicates an apical left lung infiltration. Gram stain and cultures on sputum are negative. A lung biopsy specimen culture, on the other hand, develops acid-fast bacilli. The lung specimen was microscopically examined.  Which of the following processes is most likely to contribute to formation of the finding indicated by the arrow?

Quizplus · Accepted Answer

Eductional Objective: Mycobacterium tuberculosis triggers CD4 T lymphocytes to release interferon-gamma, which leads to macrophage activation (improves intracellular killing ability) and differentiation into epithelioid histiocytes.  These cells, along with horseshoe-shaped, multinucleated Langhans giant cells (fused, activated macrophages) are a key component of granuloma formation.

A 44-Year-Old Man Arrives to the Emergency Department with a Persistent