Apical Pleural Thickening on Chest X-ray

Apical pleural thickening on chest X-ray means that there is a white area of thickening at the very top of the lungs on the chest X-ray.  This is a common benign finding which is most commonly seen from scar tissue.  This can be on both sides of the lung or a single side.  The cause is usually unknown.  The finding increases as we age, but can be see on across the spectrum of ages.

What does apical pleural thickening look like?

It is so common that some radiologists may not even mention it.  It is usually thin and white in appearance on the order of 5 millimeters or smaller in thickness and wider than it is tall.  It may have an undulating border.  Sometimes you see multiple small patchy areas along the very top of the lungs.  It is sometimes asymmetric in appearance.  One side will look different from the other.

What should be done about apical pleural thickening?

Nothing needs to be done about this finding.  No further testing is needed in most cases.   At times, this finding may be thicker than usual, or appear more mass like.  Some people can have more extensive white areas at the top of the lungs which raise the possibility of infections and cancer.

What are some other conditions that can look like apical pleural thickening?

Infections like pneumonia and tuberculosis can also happen at the top of the lungs.  They are often more extensive and rarely confused for apical pleural thickening or scarring.   Often these patients will be symptomatic with cough, fever and systemic symptoms.  CT of the chest can be done in cases which are uncertain.

Cancer can also occur at the top of the lungs and rarely mimic apical pleural thickening.  This possibility is raised when one side is much thicker or mass like than the other.  In some cases, it is still scarring.  CT will help in cases which are uncertain.  Even after CT, there may be some uncertainty to the diagnosis.  PET scan which looks at the metabolic activity will be helpful.  Cancer will be much more metabolically active than scar tissue.

Sometimes fluid in the lungs can track up to the very top of the lungs when the patient is on their back.  This can also occur after trauma when blood tracks to the very top of the chest.  Scarring from prior treatment with radiation can also give the appearance of apical pleural thickening.

Apical pleural thickening is a common benign finding found on many X-rays.  It is more common as we age.  It does not need follow up.  In rare cases, there may be an unusual appearance which may need more testing with CT.  Old X-rays are very helpful to show the area at the top of the lungs has not changed.