Sclerosing mesenteritis: a rare abdominal condition

The mesentery is a fold of tissue, rich in fat, blood vessels and lymph nodes, that attaches the small intestine to the back of the abdomen. In sclerosing mesenteritis this tissue becomes inflamed, and over time can develop fat necrosis and fibrous scarring. A case report in Cureus calls it a rare benign idiopathic inflammatory disorder, and a second published case series calls it exceedingly rare, resulting in chronic, progressive inflammatory changes.

The name varies with the dominant finding under the microscope. Fat necrosis with foamy immune cells is sometimes called mesenteric lipodystrophy, chronic inflammation is called mesenteric panniculitis and scarring is called retractile mesenteritis, though the Cureus authors note these may not be true stages because they can be present at the same time.

The Cureus report cites a figure of 0.6% of more than 7,000 consecutive patients who had abdominal CT scans, which suggests it is found not so rarely when people are scanned, but that figure comes from a single series and should be read cautiously. It describes a male predominance of about two to one and a typical age in the sixties.

Because most information comes from case reports and small series from hospitals, the true frequency and the full range of the condition are uncertain. No UK national guideline or patient charity guide was found for this page.

The reported symptoms are non-specific. The Cureus authors list chronic abdominal pain as the main complaint, with bloating, nausea, vomiting, diarrhoea, constipation, loss of appetite and weight loss. They note that anorexia and weight loss point more towards a neoplastic cause, which is one reason doctors look carefully for other diseases. On examination there may be abdominal tenderness, and sometimes a mass.

The case series in the same journal says patients may also present with complications such as bowel obstruction, obstructive uropathy or reduced blood flow to the bowel (mesenteric ischaemia). Because the symptoms resemble those of common conditions, diagnosis can be delayed; one of the reports describes a patient whose symptoms were first attributed to irritable bowel syndrome.

• Long-standing or recurrent abdominal pain, often in the middle of the abdomen.

• Bloating, nausea or vomiting.

• Diarrhoea, constipation or alternating bowel habit.

• Reduced appetite and weight loss, which always warrant medical review.

• No symptoms at all in some people.

According to the Cureus report, CT is the most convenient diagnostic tool, and the most sensitive imaging is a dual-phase CT showing a fat ring or halo sign and a tumour pseudocapsule. A hazy, misty-looking mesentery is a consistent CT finding but is not specific, as it can also be seen with neoplastic infiltration and portal hypertension. MRI findings are similar, and FDG PET may help to exclude cancer because sclerosing mesenteritis does not usually take up the tracer.

Blood tests are usually normal, although inflammatory markers such as C-reactive protein may be raised. The second case series says a definitive diagnosis is made on histological evaluation, meaning a biopsy examined under the microscope, and warns that scans meant to look for neuroendocrine tumours can give false-positive results in inflammatory conditions.

Some reports have suggested that sclerosing mesenteritis may be a paraneoplastic syndrome, but the Cureus authors describe the data as conflicting: some studies found no difference in cancer rates, while others found more cancer, with lymphoma, melanoma, colon and prostate cancers the most often mentioned. They advise a thorough history and physical examination, including a detailed skin examination, and that suspicious lesions are investigated with PET and biopsy.

This does not mean the condition is cancer. It means a doctor will usually want to make sure that nothing else is going on, and will keep up with routine cancer screening.

There is no agreed standard. The Cureus authors say asymptomatic people can be managed without medication, treatment for those with symptoms is usually individualised, and spontaneous resolution frequently occurs without treatment. Corticosteroids helped some people; colchicine, tamoxifen, azathioprine, methotrexate and infliximab have also been tried, but the authors stress that the evidence comes from case series, so the best medical approach remains unclear.

Surgery is sometimes difficult because of the extent of disease and involvement of blood vessels, but is required for complications such as perforation, or vascular or intestinal obstruction. The second case series concludes that early diagnosis matters to prevent serious complications in an otherwise benign disease.

See a GP for abdominal pain that keeps returning, or for unexplained weight loss or a change in bowel habit. Call NHS 111 or seek urgent care for severe or worsening abdominal pain, repeated vomiting, a swollen tummy with inability to pass wind or stool, or blood in vomit or poo. Anyone told after a scan that they have a misty mesentery should ask their doctor what follow-up is advised.