However, your doctor may suspect a lung nodule is cancerous if it grows quickly or has ridged edges. Even if your doctor believes the nodule is benign or noncancerous, he or she may order follow-up chest scans for some time to monitor the nodule and identify any changes in size, shape or appearance.
Nodules between 6 mm and 10 mm need to be carefully assessed. Nodules greater than 10 mm in diameter should be biopsied or removed due to the 80 percent probability that they are malignant. Nodules greater than 3 cm are referred to as lung masses.
If your nodule is large or is growing, you might need more tests to see if it's cancer. This might include imaging tests, such as CT and positron emission tomography (PET) scans. Another test might be a procedure called a biopsy. This involves removing a piece of the nodule for testing in a lab.
Most lung nodules are benign (not cancerous). Rarely, pulmonary nodules are a sign of lung cancer. Lung nodules show up on imaging scans like X-rays or CT scans. Your healthcare provider may refer to the growth as a spot on the lung, coin lesion or shadow.
Positron emission tomography (PET) scan: The PET scan will light up the nodule if it is rapidly growing or active. The brighter the nodule appears on the PET scan, the more likely that it is cancer. The PET scan also looks at the rest of the body and can identify if the cancer has spread.
The Mechanics of Pulmonary Nodules
There is very little growth or change, if there's any at all. Cancerous pulmonary nodules, however, are known to grow relatively quickly—usually doubling in size every four months but sometimes as fast as every 25 days.
PET/CT-guided percutaneous bone biopsy, compared with CT-guided bone biopsy, is an effective and safe alternative that yields a high diagnostic performance in the evaluation of hypermetabolic bone lesions to diagnose bone tumors and tumor-like lesions.
The short answer is no. A CT scan usually isn't enough to tell whether a lung nodule is a benign tumor or a cancerous lump. A biopsy is the only way to confirm a lung cancer diagnosis. But the nodule's characteristics as seen on a CT scan may offer clues.
The most common causes of lung nodules are inflamed tissue due to an infection or inflammation (called granulomas) or benign lung tumors (such as hamartomas). Less common, malignant lung nodules are typically caused by lung cancer or other cancers that have spread to the lungs (metastatic cancer).
Location. Location of nodules in the lung is another important predictor as nodules on the upper lobes are more likely to be malignant. Although etiology of this predilection is unclear, higher concentration of inhaled carcinogens could be a possibility.
Treatment for a cancerous nodule
A doctor may request a thoracotomy to remove a cancerous nodule. This surgical procedure involves removing the nodule through an incision in the chest wall. Additional treatments for cancerous lung nodules may include chemotherapy, radiation therapy, and other surgical interventions.
However, your doctor may suspect a lung nodule is cancerous if it grows quickly or has ridged edges. Even if your doctor believes the nodule is benign or noncancerous, he or she may order follow-up chest scans for some time to monitor the nodule and identify any changes in size, shape or appearance.
In the vast majority of cases, lung nodules turn out to be small benign scars, indicating the site of a previous small area of infection. These nodules may be permanent or may even spontaneously disappear by the time of the next scan. Most are of absolutely no consequence.
Biopsies are usually not recommended when nodules are small because it is very difficult to biopsy them safely. Doing a biopsy when a nodule is small can cause harm such as trouble breathing, bleeding, or infection. Biopsies are often done for nodules that are 9 mm or larger.
Most patients with lung nodules will schedule periodic follow-up appointments at 3-, 6-, or 12-month intervals to see if the lung nodule grows or changes over time. This ensures your care team can catch any signs of lung cancer early—or provide peace of mind that you don't have cancer.
If there is a higher chance that the nodule is cancer (or if the nodule can't be reached with a needle or bronchoscope), surgery might be done to remove the nodule and some surrounding lung tissue. Sometimes larger parts of the lung might be removed as well.
Benign lung nodules usually cause no symptoms. If the nodule is malignant, the patient may develop a new cough or possibly cough up blood. Most of the time, the patient is unaware of the presence of a nodule until a chest X-ray or CT scan is performed.
Lung nodules are quite common and are found on one in 500 chest X-rays and one in 100 CT scans of the chest. Lung nodules are being recognized more frequently with the wider application of CT screening for lung cancer. Roughly half of people who smoke over the age of 50 will have nodules on a CT scan of their chest.
Lung nodules are quite common, but most are benign.
In clinical work, imaging technologies are generally used to identify lung metastasis; however, it is difficult to distinguish malignant from benign pulmonary nodules in some patients. Thus, some benign lung nodules are misdiagnosed as lung metastases, resulting in incorrect clinical staging and treatment.
Keep in mind, however, that an ultrasound alone cannot make the diagnosis of cancer. This test will usually help determine that the nodule has a low chance of being cancerous (has characteristics of a benign nodule), or that it has some characteristics of a cancerous nodule, and therefore a biopsy is indicated.
4.3.
Regularly shaped pulmonary nodules were slightly more frequent in never smokers (93.4%) compared to current smokers (90.2%). The same was observed for pulmonary nodules with smooth margin (never smokers (93.8%) compared to current smokers (90.4%)).
Though most cancers are picked up on PET CT, there are a few which do not. The most important of these would be cancer of stomach (signet cell type). In such cases performing this test would be waste. However, there are cancers which are very sensitively detected which include lymphoma, GIST, etc.
FDG-positive lesions often mean cancer, but not always. A variety of lesions have increased FDG radiotracer including infection, inflammation, autoimmune processes, sarcoidosis, and benign tumors. If such conditions are not identified accurately and in a timely manner, misdiagnosis can lead to inadequate therapies.
The NCCN guidelines give detailed recommendations for the use of PET/CT across all stages of NSCLC; these guidelines note that PET/CT may be best performed prior to biopsy.