In general, a “pulmonary nodule” is a small, roundish growth on the lung that measures three centimeters in diameter or less. If the growth is larger than that, it is called a “pulmonary mass.” While pulmonary nodules may grow to become a pulmonary mass, some nodules may not grow at all. There are many causes of pulmonary nodules. These include infection, such as fungal or bacterial infections, noncancerous processes, such as sarcoidosis, or cancerous processes, such as lung cancer, lymphoma, or metastatic cancer from other organs. The likelihood that a pulmonary nodule represents lung cancer depends upon three major factors, your age, your smoking history, and your environmental exposure history. Generally, less than 10 percent of pulmonary nodules turn out to be lung cancer.
Symptoms of Pulmonary Nodules
Because pulmonary nodules are small, they rarely cause any symptoms. Some patients might experience symptoms of a respiratory infection, such as a symptoms associated with chest colds or mild flu. Most pulmonary nodules are discovered by accident, when a patient gets a chest X-ray or a CT scan performed for another purpose.
Evaluating a Pulmonary Nodule
The immediate goal of evaluating a pulmonary nodule is determining the cancerous potential of the nodule. This is first done with a thorough evaluation of the personal and medical history, the environmental exposure history, and the chest CT scan. If a nodule is determined to have significant cancer potential and is one centimeter in diameter or greater, diagnostic procedures are used to determine the cause of the pulmonary nodule. There are many approaches to evaluating and diagnosing pulmonary nodules that do not require surgery, such as PET scans, bronchoscopy, endobronchial ultrasound, CT-guided needle biopsy, and fluoroscopically guided biopsy. When the pulmonary nodule cannot be diagnosed using these noninvasive approaches, surgical approaches are considered, such as video-assisted thorocoscopic surgery, a mini-thoracotomy, or a thoracotomy. Once the cause of the pulmonary nodule has been determined, an appropriate treatment plan tailored to the disease can be assembled.
Following a Pulmonary Nodule
The majority of pulmonary nodules are extremely small, less than one centimeter in diameter. Unfortunately, these pulmonary nodules are too small to be diagnosed safely and accurately using any of the currently available procedures or tests. Because these very small pulmonary nodules can represent early lung cancer, they need to be followed closely using CT scans with a well developed algorithm for evaluating whether the pulmonary nodule has grown over time. If the size of these pulmonary nodules remains unchanged for two years, the likelihood of these pulmonary nodules representing lung cancer is very small.