Mesenteric Panniculitis

Mesenteric panniculitis is most commonly seen on CT scans of the abdomen as inflammation of the mesentery.  We can see findings of mesenteric panniculitis both as an incidental finding and one that causes symptoms in patients.  The appearance on CT is often referred to as a misty mesentery.

What is mesenteric panniculitis of the abdomen?

Mesenteric panniculitis is a chronic inflammation of the fat of the small bowel mesentery of unknown cause.  The mesentery is the tissue that encloses and attaches the intestines to the abdominal wall.  The inflammation can destroy the fat tissue and eventually progress to scarring.

Symptoms of mesenteric panniculitis

Most patients have mild symptoms.  This can include abdominal pain, bloating, nausea/vomiting, fever and rarely obstruction of the bowel.  Some patients are asymptomatic.

What is idiopathic sclerosing mesenteritis?

This is another term for mesenteric panniculitis where the predominance of disease is that of scarring in the mesentery. Mesenteric lipodystrophy also refers to inflammation in the mesentery but with predominant fat necrosis or cell death.  Some believe that these terms represent the same disease at different stages.

Mesenteric panniculitis in radiology

We often see a hazy appearance of the fat on CT in mesenteric panniculitis. There are small less than 1 cm lymph nodes which appear clustered.  The surrounding bowel may be pushed by this process.  We can also see mesenteric panniculitis on MRI of the abdomen.  We can not see mesenteric panniculitis on X-ray.

What else can look like mesenteric panniculitis on imaging? (misty mesentery)

Misty mesentery means the normal fat of the mesentery is replaced by haziness.  This can mean mesenteric panniculitis but can have other causes.

We can not always tell if the abnormality in the mesentery is that of chronic inflammation or cancer on CT.  PET CT testing may help differentiate cancer from mesenteric panniculitis.   Biopsy may be needed in some cases.

Other causes of misty mesentery can be other inflammatory conditions of the abdomen like pancreatitis, appendicitis, diverticulitis to name a few.  Often we can make a specific diagnosis on CT of the these conditions.

What causes mesenteric panniculitis?

No one is sure what causes mesenteric pannicultis.   Some believe it may be an autoimmune condition where the immune system reacts for an unknown reason since there is no clear underlying cause.

Mesenteric pannicultits has been associated with prior abdominal surgery or trauma.

There are associations with prior infections like tuberculosis and syphilis.

Mesenteric pannicultits has occurred in patients who have been previously treated for cancer.   It has also been seen in patients with known cancer or cancer which is present but has not been diagnosed. Some of the cancers which have been associated with mesenteric pannicultis have been: Colon, kidney, lymphoma and prostate cancer.

There is an association with systemic inflammatory and autoimmune conditions.

Is mesenteric panniculitis dangerous?

It’s not life threatening and does not cause serious problems in most patients.  Most patients have mild symptoms. Rare intestinal blockages can be seen.

Mesenteric panniculitis treatment

Many cases can simply be observed when there are mild symptoms.  Often the mesenteric inflammation goes away on its own.  Steroids and immunosuppressants are used for more severe cases.

Mesenteric panniculitis: summary

Mesenteric pannicultis is a chronic inflammation of the mesentery in your abdomen of unknown cause.  It often has no or mild symptoms and goes away on its own.

We can see mesenteric panniculitis on imaging studies like CT.  This will look like a misty or hazy mesentery often associated with small lymph nodes.   There are some associated conditions like infections and cancer.