Widened mediastinum on chest X-ray means the central part of the chest between the lungs look wider then usual. This has many causes some of which are benign and represent normal anatomy, while others are life threatening.
What Is The Mediastinum?
The mediastinum is the space between your lungs in the chest. The mediastinum has blood vessels, lymph nodes, fatty tissue, nerves and other structures. The mediastinum is between the lungs on a chest x ray as a white area. Read more here: mediastinum definition.
What does widened mediastinum mean?
Sometimes the mediastinum is described as widened by the radiologist. This is usually subjective and based on the radiologists experience. Measurements can be made but these are not reliable.
What causes a widened mediastinum?
Many of the causes are benign such as variants of normal anatomy involving blood vessels in the chest. There can be more then usual fat accumulation in the mediastinum causing widening. Technical factors such as positioning and supine positioning can cause a widened mediastinum. Other more concerning causes can include bleeding in the chest after trauma, tumors, enlarged lymph nodes and aneurysms.
Widened mediastinum finding on chest x-ray
The radiologist sees this finding as a widening of the space between your lungs. This is a subjective finding which the radiologist often bases on his experience of looking at thousands of prior chest x rays. Sometimes there are clues to the cause of this appearance, but in most cases, a chest CT is needed to look further.
Should I be worried about widened mediastinum?
Bleeding from aortic injury
Your history is often helpful. Say for instance you had a bad car accident, then bleeding becomes a concern from injury to the aorta.
Cancer and widened mediastinum
In other cases, a lumpy and bumpy contour of the widened mediastinum suggests that big lymph nodes and cancer may be a cause. Masses may also develop from structures like the thymus, thyroid, nerves and lung causing a widened mediastinum.
Widened mediastinum and aneurysm
Another dangerous condition can be an aneurysm of the aorta, which passes through the mediastinum.
Widened mediastinum and normal variants
Most cases of widened mediastinum on chest X-ray are from benign or non life threatening causes. If you are a heavy set person, then the appearance may simply be because of fat accumulation. Blood vessels anatomic variants can cause a widened appearance. Sometimes the appearance is from the technique that was done to take the chest X-ray. In all cases, further evaluation is CT is warranted to exclude more serious causes.
Your history is important to determine the cause of widened mediastinum
This is a finding in which the history and physical exam findings are especially important. For example, a widened mediastinum after a car accident may indicate potentially lethal bleeding. Night sweats, fatigue, and weight loss may indicate cancer. A well feeling patient without complaints may indicate the finding is due to fat accumulation or even the technique taken for the x ray. It is therefore important to have your doctor closely evaluate you when this finding is described in a chest x ray.