Misty Mesentery

Misty mesentery is an imaging finding where the mesentery of the small bowel becomes hazy in appearance.  Misty mesentery does not tell us a diagnosis but simply is a descriptive term found on imaging.  There are multiple diagnostic possibilities for this finding.  Associated clinical and imaging findings will help sort out the possibilities.

What is misty mesentery?

Misty mesentery is an imaging finding that is found most commonly on CT scans. The mesentery attaches the intestine to the abdominal wall.  The fat within the mesentery becomes hazy or ground glass instead of black like normal fat.

Symptoms of misty mesentery

The symptoms depend on the underlying cause.  The finding may be asymptomatic or associated with a life threatening condition depending on the cause.

What does misty mesentery look like on a scan?

Misty mesentery looks like haziness in the fat of the mesentery.  The fat is normally black.  MRI of the abdomen will also show this finding.  X-ray does not show us a misty mesentery.

What else can look like misty mesentery in radiology?

One of the more common conditions is called mesenteric panniculitis.   This is a chronic inflammation of the small bowel mesentery of unknown cause.  There are many associations like prior surgery, infections and cancer.  This causes a misty mesentery with multiple small clustered lymph nodes.  The condition is often self limited and has no or mild symptoms.

We can see misty mesentery as a result of edema/fluid from portal hypertension.  This is most common in cirrhotic patients.

An occluded or thrombosed superior mesenteric vein in the abdomen can result in edema or misty mesentery.

Cancers like lymphoma can cause a misty mesentery.  Often we will see enlarged lymph nodes with lymphoma.   There will often be a history of cancer or additional findings on the scan to help with this diagnosis.

Inflammatory conditions in the abdomen like appendicitis, diverticulitis and pancreatitis will sometimes be associated with a misty mesentery.  Often we can make a specific diagnosis of these conditions on CT.  The misty mesentery is an associated finding.

What causes misty mesentery?

This is usually caused by infiltration of the mesentery by fluid, inflammation, blood, or abnormal cells.

Is misty mesentery dangerous?

It depends on the cause and any associated findings.  It is often a benign incidental finding we see when we image patients for other reasons.  If we see some other findings on the scan in addition to misty mesentery like big lymph nodes or inflammation somewhere else, then we become more concerned.

Does misty mesentery mean you have cancer?

Usually not.  Misty mesentery by itself is often a benign finding.  We become concerned when we see additional findings on the scan that indicate cancer.  This can be enlarged lymph nodes or a mass somewhere else.  Mesenteric panniculitis causes a misty mesentery and has been associated with cancer.

Misty mesentery treatment

The treatment will depend on the cause.  Misty mesentery by itself is often a benign or asymptomatic finding.  It often goes away on its own.

Associated findings on the scan like cancer, inflammation somewhere else in the abdomen, or a thrombosed vessel will have to be treated.

Misty mesentery: summary

Misty mesentery is an imaging finding most common on CT scans which means the small bowel mesentery is hazy or misty.  This does not tell us a specific diagnosis.  We can sometimes see additional findings on the scan which help us explain the cause of the misty mesentery.