Final answer:
Benign pulmonary nodules are smooth, well-defined, and typically smaller than 3 cm, distinguishing them from malignant ones. They may indicate conditions like sarcoidosis or tuberculosis, with radiographs showing features like cavitation and Ghon complexes.
Step-by-step explanation:
Benign pulmonary nodules are non-cancerous growths that can appear in the lungs. They are usually detected incidentally during chest imaging, such as radiographs (X-rays) or CT scans. Benign nodules have features that distinguish them from malignant lung nodules. These features include a smooth, well-defined edge, a size typically less than 3 cm in diameter, and a lack of change in size over time when monitored.
In the context of pulmonary diseases, inflammation of the conjunctiva with nodules may indicate conditions such as sarcoidosis or tuberculosis, and the formation of tubercles in the lungs can burst, leading to a chronic, bloody cough. Features possibly seen in a radiograph include bilateral pulmonary infiltrate, and in the case of tuberculosis, cavitation and healed tubercles known as Ghon complexes. Bronchus-associated lymphoid tissue (BALT) may be involved in the body's innate immune response to inhaled pathogens, providing a barrier defense.