Mesenteric panniculitis in Merseyside: a case series and a review of the literature

Abstract

Mesenteric panniculitis (also known as mesenteric manifestation of Weber–Christian disease, isolated lipodystrophy and mesenteric lipogranuloma), a benign inflammatory or fibrotic change in the mesentery of the bowel, is a rare diagnosis, particularly in the UK. Some 213 cases have been reported in the world-wide literature, just six from the UK. We present four cases of mesenteric panniculitis in Merseyside and review the literature surrounding this poorly understood phenomenon. Four patients who attended surgical out-patients with vague abdominal symptoms, and in two cases a palpable mass, were sent for abdominal computed tomography (CT) scan. One patient was admitted as an emergency with abdominal pain. In each patient there were clear signs of mesenteric panniculitis, first described in 1924. The ’classical’ signs of mesenteric panniculitis seen on CT have been argued by some to be pathognemonic of the disease. In two cases, the patients underwent laparoscopic biopsies to confirm the diagnosis. We discuss the literature relating to mesenteric panniculitis, theories about its aetiology, confirmation of the diagnosis and consider the possibility that it is not actually as rare as we think. We suggest that it is rather under diagnosed due to the relative ignorance of the condition amongst both surgeons and radiologists the UK compared to the US, where mesenteric panniculitis is far more widely reported.

First described by Jura in 1924, mesenteric panniculitis is a relatively common, but rarely reported, benign condition affecting the mesentery of the bowel; characterised by the presence of fat necrosis, chronic inflammation and fibrosis.¹ Mesenteric panniculitis is known by several other names including: mesenteric lipodystrophy; retractile mesenteritis; mesenteric manifestation of Weber–Christian disease.

We shall discuss the histological subcategories which have been proposed by Mata and colleagues. Mesenteric panniculitis is of particular interest to surgeons as it has been shown to be the cause of chronic abdominal pain when other diagnoses have been excluded. There have been 213 case reports in the world-wide literature with a preponderance of cases in the US, France and Japan. We present four cases of mesenteric panniculitis in Merseyside, UK and discuss the diagnosis with reference to the published cases so far.

Case histories

Patient A

A 65-year-old woman who attended surgical out-patients with a long history of non-specific, right upper quadrant and peri-umbilical pain. Clinically, she was obese with mild tenderness in the right upper quadrant and a palpable fullness peri-umbilically, thought to be intraperitoneal. Her blood results showed her to be mildly icteric with a bilirubin of 28 μmol/l. An ultrasound scan demonstrated an unremarkable biliary tree. A computed tomography (CT) scan of her abdomen revealed the classical findings of mesenteric panniculitis (Fig. 1).

Figure 1.

Abdominal CT scan of patient A showing a heterogeneous mass at the root of the mesentery.

Patient B

A 62-year-old man who was also seen in surgical out-patients with a 1-month history of nausea and anorexia accompanied by an abdominal pain and palpable localised central mass. Blood tests were unremarkable other than a raised erythrocyte sedimentation rate (21 mm) and a subsequent CT scan revealed findings consistent with mesenteric panniculitis (Figs 2 and 3). Biopsies were taken laparoscopically which confirmed the diagnosis histologically.

Figure 2.

Saggital section from the abdominal CT scan of patient B. The pseudotumour stripe is clearly visible.

Figure 3.

A further image from the abdominal CT scan of patient B; here, the classical displacement without invasion of the mesenteric vessels is illustrated.

Patient C

A 68-year-old woman who presented as an urgent referral with malaise, anaemia and abdominal pain. Abdominal examination was unremarkable and blood tests revealed a mild hypochromic anaemia (11.2 g/dl) but nothing else of note. Initially, she was managed as a possible colonic cancer and, following a negative colonoscopy, underwent a CT scan of her abdomen. Once again, this demonstrated radiographic evidence of mesenteric panniculitis.

Patient D

A 63-year-old man with a background of a hiatus hernia and Barrett’s oesophagus was admitted as an emergency with epigastric and central abdominal pain. Blood tests were unremarkable except for a C-reactive protein level of 55 mg/l. Plain chest and abdominal radiography were normal and the patient was discharged home with an increase in his proton pump inhibitor. One week later, he re-presented with similar symptoms and underwent a CT abdomen which revealed a 10 × 4 cm area of mesenteric panniculitis at the root of the small bowel mesentery. Laparoscopic biopsy was performed and the histology correlated with the diagnosis. A repeat CT scan 4 months later was reported as showing an appreciable decrease in the size of the area of mesenteric panniculitis.

Discussion and literature review

Mesenteric panniculitis has been estimated to affect 1% of the population based on findings at over 700 post-mortem examinations.² There is a slight male preponderance with a 1.8:1 ratio reported in some series.³ The aetiology is unknown but causative factors which have been postulated include infection, trauma and ischaemia.⁴ Mesenteric panniculitis has also been seen in conjunction with: vasculitis (Weber–Christian disease), granulomatous disease, malignancy and pancreatitis.⁵ One case reported mesenteric panniculitis caused by abdominal tuberculosis infection.⁴ There have been two cases of mesenteric panniculitis occurring as the initial presentation of systemic lupus erythematosus.⁶ Van der Hulst and colleagues⁷ have reported a case attributed to the use of a pneumatic jackhammer. However, no definitive common factor has been identified and there is no increased prevalence among patients with an intra-abdominal malignancy.⁸ As far as we are aware, there have been no published cases of mesenteric panniculitis occurring concomitantly with inflammatory bowel disease. A history of previous abdominal surgery is also shown to be of no significance.⁹

Patients usually present with vague abdominal fullness and pain in the upper or central abdomen.⁹ There may also be nausea, altered bowel habit and lethargy. Rectal bleeding is an unusual presentation for mesenteric panniculitis.¹⁰ Mesenteric panniculitis is most often an incidental finding during an investigation for gallbladder disease, as in patient A. The most common physical finding is a poorly defined mass or masses in the right upper quadrant.⁹

Laboratory investigations are usually grossly normal. One study found that 60% of patients had a raised erythrocyte sedimentation rate.⁹ Other studies mention the common finding of a non-specific anaemia in conjunction with a raised erythrocyte sedimentation rate, as seen in patient C.¹¹

Imaging is perhaps the most useful non-invasive investigation for mesenteric panniculitis with at least one study suggesting that CT changes are so classical that the diagnosis can me made from this imaging modality alone.¹⁰ The plain abdominal X-ray has very little diagnostic value in mesenteric panniculitis; similarly, barium and other contrast studies were unhelpful.^9,10 Ultrasound investigations have revealed three distinct changes thought to be due to mesenteric panniculitis.³ Unfortunately, these are by no means unique to mesenteric panniculitis and so can not be relied upon to confirm the diagnosis. Equally, Doppler studies reveal only mesenteric vessels within a mass and high resistance flow in terminal jejunal or ileal vessels.¹²

The CT changes seen in mesenteric panniculitis depend in large part upon the stage of the disease and whether the disease process is inflammatory mesenteric panniculitis or fibrotic mesenteric panniculitis.¹³ In general, CT changes consistent with mesenteric panniculitis include encapsulated, heterogeneous masses localised to the root of the mesentery or adjacent intestinal loops.¹³ The intestinal wall is thickened occasionally. Daskalogiannaki et al.⁸ reviewed 7620 abdominal CT scans in which 49 (0.6%) had changes consistent with mesenteric panniculitis. Almost all patients had a left-sided orientation of disease with scattered, well-defined soft tissue nodules of < 5mm. Of patients, 59.2% had a ‘pseudotumoural stripe’ of tissue surrounding the mass lesion.⁹ The ‘pseudotumoural stripe’ has previously been suggested to be pathognemonic of mesenteric panniculitis, especially when seen in conjunction with mesenteric vessels which are surrounded or displaced by fat but not invaded.^10,14

Definitive diagnosis is still made by histopathological evaluation of tissue either resected at laparotomy or sampled via laparoscopic of CT-guided biopsy. Macroscopically, the mesentery is enlarged and may be diffuse, nodular or multi-nodular – mimicking a malignant neoplastic change or a lymphoma. Microscopically, mesenteric panniculitis is distinguished by the presence of multiple anomalous fatty cells with foamy cytoplasm and infiltration by monocytes, lymphocytes, lipid-laden macrophages and giant cells.¹⁰ There is usually an element of fat necrosis which may calcify, although such calcification is rarely seen on the CT images.¹⁵ Mesenteric panniculitis is known by many other names; Mata and colleagues¹³ suggested that these can be subdivided based upon their histological descriptions (Table 1).

Table 1.

Histological classification of mesenteric panniculitis

Inflammatory or fatty change  Mesenteric lipodystrophy1  Mesenteric manifestation of Weber–Christian disease16  Isolated lipodystrophy17  Mesenteric lipogranuloma18  Pseudotumoural intra-abdominal panniculitis5

Fibrotic change  Sclerosing mesenteritis1  Chronic fibrous mesenteritis5  Retractile mesenteritis19

After Mata et al.¹³

Mesenteric panniculitis is reported to be a self-limiting condition, initially said to regress spontaneously after 3 months as in patient D.⁹ However, case series have emerged which show that follow-up CT scans between 3–5 months mostly show no change in the size of the mass lesion.⁸ Steroid therapy and immunosuppressant treatments have been postulated to show some clinical improvement but there has been no randomised controlled trial to date.

A search of the case report literature using the terms ‘mesenteric panniculitis’, ‘retractile mesenteritis’, and ‘mesenteric manifestation of Weber–Christian disease’ revealed 218 publications between 1965 and 2008. Of these, 12 (5.5%) gave no geographical location within the accessible data and five (2.3%) were not case reports at all. Of the remaining 201 published case reports, 41 (20.4%) were from the US. In comparison, six (3.0%) were from the UK. These findings indicate that mesenteric panniculitis is diagnosed 1.3 times more often in the US than in the UK.

Conclusions

Although a benign entity, mesenteric panniculitis is of growing interest to surgeons because of its presentation as a chronic abdominal pain in the presence of other symptoms suggestive of a lower gastrointestinal malignancy of gallstone disease. Despite being a rarely reported condition, it can be diagnosed from a CT scan of the abdomen and may become a more common diagnosis as radiologists become adept at recognising the changes seen on CT. It is possible that a CT scan of the abdomen is sufficient to confirm the diagnosis thus removing the need for more invasive investigations and biopsies for our patients. There is little data on the place of magnetic resonance imaging in the diagnosis of mesenteric panniculitis.

We suggest that, although the disease process is not understood, it is a primary pathology, unrelated to other conditions which have been shown to be within the range of expected incidence for the age group studied. We further suggest that the two published case reports involving children may point to a pathological process occurring commonly in paediatric patients who often present with unexplained abdominal pain and for whom mesenteric adenitis does not fit the symptoms. The lack of CT scans in this age group means that such a hypothesis cannot be readily tested.

Geographical variation amongst reported cases of mesenteric panniculitis may be due to the availability and usage rates of CT investigation.

Of significance is the fact that none of the 10 consultant surgeons and only one of the 12 consultant radiologists working in our institution had any knowledge of mesenteric panniculitis. This would seem to suggest that, although it is common, it may be under reported in the UK.

Hopefully recognition of the existence of this condition should lead to increased awareness among surgeons when considering their differential diagnoses of abdominal pain.

Although thought to be a self-limiting disease, striving to recognise mesenteric panniculitis among more patients with ‘abdominal pain of unknown cause’ will fuel a search for treatments and aid patients in understanding and consequently managing their symptoms.