A lung nodule is an abnormality in the lung often found on a chest X-ray or CT scan of the chest. Once a patient is diagnosed with a lung nodule, the goal is to determine the probability of the nodule being a malignancy. Based on this probability, we recommend different strategies to manage the lung nodule.
The lung nodule could be a benign lesion such as pneumonia, granuloma or hamartoma. The nodule could also be the primary cancer from the lungs or cancer that has travelled to the lung from other sites such as metastatic cancer. In order to best determine the probability that a nodule is a malignancy, we use information about the patient and the nodule’s characteristics. Some patient factors that increase concern for malignancy are whether the patient currently smokes or has a significant history of smoking in the past, a personal history of cancer, is older and has no signs of infection such as fever, chills and cough. Some imaging factors that increase the risk of malignancy include a large nodule, whether the nodule’s size increases over time, a spiculated nodule and lack of calcification.
Based on these factors, we estimate a low, moderate or high probability of the nodule being a malignancy. Based on the probability, we manage the lung nodules with treatments that provide the best way to get the necessary information with the least amount of intervention to the patient. All of this is performed with the understanding that the only way to be 100% accurate in our diagnosis is to remove the nodule, but that most nodules will likely be benign and do not require removal of the nodule.
For patients with a low probability of the nodule being a malignancy, we typically recommend for the patient to repeat the CT scan within a period of time. Generally, stability of the nodule over time signifies that the nodule is less likely to be a malignancy.
For patients with a moderate probability of the nodule being a malignancy, we typically recommend a PET-CT with or without a biopsy. Based on the location, the biopsy can be performed either through the chest, also known as a CT guide biopsy, or through the airway, also known as an electromagnetic navigational bronchoscopy.
- PET-CT – This study is performed in radiology. It provides information about the lung nodule and its possible spread to lymph nodes and other parts of the body except for the brain.
- CT guided biopsy or transthoracic needle biopsy – This study is performed in radiology. It is an outpatient procedure in which a needle is used to take sample of the nodule to allow the pathologist to diagnose the nodule.
- Electromagnetic navigational bronchoscopy or transbronchial needle biopsy – This study is performed in the operating room.
For patients with a high probability of the nodule being a malignancy, we typically manage patients for treatment of early stage lung cancer. After the appropriate pre-operative testing, typically we perform a wedge resection at the time of surgery to confirm that the nodule is cancer, and then perform a standard lung cancer operation, or pulmonary lobectomy with mediastinal lymph node dissection.