Solitary Pulmonary Nodule
Symptoms of Solitary Pulmonary Nodules
Most persons with a SPN do not experience symptoms. Generally, a SPN is detected as an incidental finding.
Approximately 20%-30% of all cases of lung cancer appear as SPNs on chest X-rays. Therefore, the goal of investigating an SPN is to differentiate a benign growth from a malignant growth as soon and as accurately as possible.
SPNs should be considered potentially cancerous until proven otherwise.
People should always communicate openly and honestly with their health care provider about their history and risk factors.
The following features are important when assessing whether the SPN is benign or malignant.
- Age: Risk of malignancy increases with age.
- Risk of 3% at age 35-39 years
- Risk of 15% at age 40-49 years
- Risk of 43% at age 50-59 years
- Risk of greater than 50% in persons older than age 60
Smoking history: A history of smoking increases the chances of the SPN being malignant.
- Prior history of cancer: People with a history of cancer in other areas of the body have a greater chance that the SPN is malignant.
- Occupational risk factors for lung cancer: Exposure to asbestos, radon, nickel, chromium, vinyl chloride, and polycyclic hydrocarbons increases the chance that the SPN is malignant.
- Travel history: People who have traveled to areas with endemic mycosis (such as histoplasmosis, coccidioidomycosis, or blastomycosis) or a high prevalence of tuberculosis have a higher chance of the SPN being benign.
- People who have a history of tuberculosis or pulmonary mycosis have a greater chance of the SPN being benign.
SPN Exams and Tests
Blood tests cannot lead to a diagnosis. However, the following tests may indicate whether the SPN is benign or malignant:
Anemia (low levels of hemoglobin) or an elevated erythrocyte sedimentation rate (speed at which red blood cells settle in anticoagulated blood) may indicate an underlying cancer or an infectious disease.
- Elevated levels of liver enzymes, alkaline phosphatase, or serum calcium may indicate that the SPN is cancerous and spreading or that cancer is spreading from other parts of the body to the lung.
- Persons who have histoplasmosis or coccidioidomycosis may have high levels of immunoglobulin G and immunoglobulin M antibodies specific to these fungi.