How to Assess a Lung Lesion for the Physician Assistant Exam
A common scenario you deal with clinically and for the Physician Assistant Exam (PANCE) is inadvertently finding a lung lesion on a chest radiograph. You’re looking for something, and bam! There it is. What do you do about it? You assess the lesion on the radiograph:
Check the other lung findings to make sure that you’re just dealing with a pulmonary nodule.
Other lung findings should be normal. Examples of abnormal findings include the presence of atelectasis or a recurrent pneumonia that won’t go away despite repeated treatment with antibiotics. The presence of adenopathy, especially hilar adenopathy, should be inspected on the chest radiograph.
Know the size of the lung lesion.
The number 3 is the key. If the lung lesion is < 3 cm, you likely have a lung nodule. If it’s > 3 cm, you’re likely dealing with a lung mass. The larger the lung lesion, the more likely that you’re dealing with a malignancy.
Look at the edges of the lesion.
A lung malignancy has irregular or spiculated borders. Benign lesions tend to have smooth edges.
See whether the lesion contains calcium.
More often than not, calcification suggests a benign lesion. In fact, calcification has many benign causes, including old, healed infections or reaction to a foreign body. Granulomas are a perfect example of a nonmalignant calcified lung lesion. However, if the calcification is irregular or eccentric, there’s a higher chance that you’re dealing with a malignancy.
If all else fails and you need a better assessment of the solitary nodule, obtain a CT scan.
This step may or may not be necessary.
After you’ve looked at the characteristics of the lesion, look at the characteristics of the person.
Is he or she old or young? A smoker? An older person who smokes has a higher chance of malignancy. You can watch people who are at lower risk with serial imaging, but for those who are at higher risk, you may need to get a biopsy to find out what you’re dealing with.
You’re evaluating a 55-year-old man who presents to the ER with hemoptysis. He hasn’t been feeling well for a while. He says he has intermittent episodes of dizziness and diarrhea that comes on for no reason. He feels flushed. This has been occurring for a few weeks. You obtain a chest radiograph, and it shows a tumor located on the right mainstem bronchus. What does this lung mass likely represent?
(A) Small-cell lung cancer
(D) Carcinoid tumor
(E) Pulmonary embolus
The correct answer is Choice (D). Carcinoid tumor is a neuroendocrine tumor that, although not aggressive, is treated like a lung mass. Some patients can have the symptoms mentioned in the question, including dizziness, diarrhea, and flushing, because the tumor secretes serotonin. A CT scan is used for staging, because the most common place of spread is to the liver. The treatment is surgery.