Solitary Pulmonary Nodule

Solitary Pulmonary Nodule
A solitary pulmonary nodule is defined as a discrete lesion < 3 cm in diameter that is completely surrounded by lung parenchyma (ie, does not touch the hilum, mediastinum, or pleura) and is without associated atelectasis , consolidation or pleural effusion.
Solitary pulmonary nodules are most often detected incidentally when a chest x-ray is taken for other reasons. Non-pulmonary soft-tissue densities caused by nipple shadows, warts, cutaneous nodules, and bone abnormalities are often confused for a nodule on chest x-ray.
Etiology
Although cancer is usually the primary concern, solitary pulmonary nodules have many causes that vary by age and risk factors, but typically include Granulomas, infection or cysts.
Evaluation
The primary goal of evaluation is to detect cancer and active infection.
Features may suggest malignant or active infection causes includes
• Current or past cigarette smoking
• History of cancer or an autoimmune disorder
• Occupational risk factors for cancer (eg, exposure to asbestos, vinyl chloride, radon)
• Travel to, or living in, areas with endemic mycosis or a high prevalence of TB
• Risk factors for opportunistic infections (eg, HIV, immune deficiency)
• Older age
• Large nodule diameter