# Extensive Sclerosing Mesenteritis of the Rectosigmoid Colon Associated with Erosive Colitis

Authors: C. Nobili; L. Degrate; R. Caprotti; C. Franciosi; B. E. Leone; F. Romano; M. Dinelli; Fr. Uggeri
Journal: Gastroenterology Research and Practice
 (2009)

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## Abstract

Sclerosing mesenteritis is a rare, idiopatic, usually benign, inflammatory process of the mesenteric adipose tissue. The most common site of involvement is the small bowel mesentery. We present a case of sclerosing mesenteritis of the rectosigmoid colon as a cause of severe abdominal pain, abdominal obstruction, and ischemic colic mucosal lesions. Contrast enema, colonoscopy, angiography, and CT were the imaging modalities used. A 20 cm diameter, fibrotic mass causing extensive compression of rectosigmoid colon was found at laparotomy. Histological examination showed extended fibrosis, inflammatory cells infiltration, lipophages, and granulomas within the mesenteric adipose tissue associated with erosive colitis. Clinical presentation and treatment are discussed.


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## Body

## 1. Introduction

Sclerosing mesenteritis  (SM) is a rare, usually
benign disorder that affects the mesenteric fat tissue. This disease usually
arises from the mesentery of the small bowel and rarely involves the mesocolon
[1, 2]. SM can express microscopically as predominantly fat tissue
lesions  (termed mesenteric panniculitis) or as predominantly fibrotic lesions
(termed retractile mesenteritis). Clinical presentations and imaging patterns
are nonspecific, so only the histopathologic analysis of SM masses provides a
sound diagnosis. About the prognosis, SM can show both a favorable course and
a so much extended fibrotic process that can produce medical or surgical
urgencies. It is likely that a malignancy is associated to SM lesions, so,
although medical therapies have been proposed, only surgical complete removal
can solve complications, if present, can prevent unfavorable progress,  and can
avoid the risk of hidden metachronous cancers. We report the case of a male
patient with sclerosing mesenteritis complicated by intestinal obstruction. The
diagnosis could be performed only by anatomopathologic findings and SM was treated
by surgical resection. Discussion is focused on aetiology, histology, natural
history and treatment.


## 2. Case Report

A 59-year-old man complained of
two-month history intermittent lower abdominal pain and constipation. About one
year before, due to dyspeptic symptoms, an esophagogastroduodenoscopy was
carried out showing jatal hernia. His past medical history included only acute
myocardial infarction 13 years before. Laboratory tests were not contributory;
tumor markers carcinoembryonicantigen, alpha-fetoprotein, and
carbohydraticantigen 19.9 were negative. Barium enema demonstrated rugged
mucosa and serrated contour with narrowing of the sigmoid colon by a probable
extrinsic encasement. Then, a colonoscopy revealed reduction until 14 mm of
calibre of the sigmoid colon, with rigid walls and aphtosis of the rectum.
Histological examination of the endoscopic biopsies diagnosed ischemic colitis.
Angiography of the celiac artery and of the mesenteric arteries showed no
abnormalities.Patient’s symptoms got worse over the next
month, mucous diarrhoea appeared and the patient presented to Emergency Room.
On examination, he was afebrile. Physical examination of the abdomen revealed
slight abdominal distension and, in the lower abdomen, a firm mass without tenderness,
measuring approximately 10 cm in diameter, with mild pain on pressure,
corresponding to the sigmoid colon. Rectal examination did not reveal anything
abnormal. A computed tomography (CT) scan showed rare sigmoid divertucula and
thickened walls (about 1.5 cm) of the rectosigmoid colon, determining mild
luminal narrowing, without signs of perivisceral inflammation; liver was
normal; there was not lymphadenopathy either ascites. During the third day of
hospitalization, the patient developed obstructive symptoms with abdominal
cramping and vomiting. A laparotomy identified a fibrous, partially necrotic,
hyperaemic, 20 cm diameter mass in the mesocolon determining stenosis of the
sigmoid colon and rectum, adherent to the parietal peritoneum. The mass was resected
in toto with rectosigmoid colon; transanal anastomosis according to Knight-Griffen
and temporary protective ileostomy were performed. Postoperative course was
uneventful. Histological examination of surgical specimen revealed lipid-laden
foamy cells and chronic granulomatous inflammation of mesocolon, associated
with erosive colitis (Figures1 and 2); these findings were consistent
with idiopathic sclerosing mesocolitis; aspecific reactive lymphadenopathy of
pericolic nodes (Figure 3).Figure 1
Idiopathic retractile sclerosing mesocolitis: inflammation of intestinal wall associated with erosion of mucosa (emathoxilyn-eosin 100x original magnification).Figure 2
Idiopathic retractile sclerosing mesocolitis: lipid-laden foamy cells and chronic granulomatous inflammation of mesocolon (emathoxilyn-eosin 100x original magnification).Figure 3
Idiopathic retractile sclerosing mesocolitis: aspecific reactive lymphadenopathy of pericolic nodes and lipophagic inflammation of mesocolon (emathoxilyn-eosin 100x original magnification).Three months later, Gastrographin enema
excluded intestinal fistula, so patient underwent ileostomy surgical closure.
At two years follow-up patient is asymptomatic.


## 3. Discussion

Sclerosing mesenteritis (SM) is an uncommon
nonneoplastic inflammatory process in the mesenteric fat that rises as a
pseudotumor, usually involving the small bowel mesentery, the mesenteric fat
and, less commonly, the mesentery of the large bowel. Young adults are mainly
affected, more often men than women; about 2-3:1 [3–6], and the
incidence increases above age 50 [3], although also rare cases of
children have been reported [7].Several names are  proposed for this
disease, as SM, retractile mesenteritis, mesenteric nodular panniculitis,
mesenteric Weber-Christian disease of the mesentery, and mesenteric
lipodystrophy, but they represent histological variants of a single pathologic
entity that differs only in its proportion of fibrosis, lipid-laden
macrophages, adiponecrosis, and nonspecific inflammatory infiltration.
Microscopic diagnostic findings are chronic inflammatory process of the
mesentery, characterized by fibrosis, myofibroblasts, and inflammatory cells
infiltration, degeneration of the fatty tissue or fat necrosis; aggregations of
lipid-laden foamy macrophages are also present and they can be distributed in
bands of variable width or in scattered areas [3, 8, 9]. Two patterns of
expression are known: mesenteric panniculitis (if, at histology, the lesion is
characterized more by inflammation and fat necrosis than by fibrosis) and retractile
mesenteritis (when the lesion is characterized by predominant fibrosis)   [1, 10].
Our patient showed predominant inflammation and fat changes rather than
fibrosis. The lesions are usually single mass; multiple masses or diffuse
thickening of the mesentery are less common [5, 9]. The present case
involved the large bowel mesentery with a single mass.There is lack of consensus about the etiology
of SM. Several causes have been hypothesized, as ischemia, infections, previous
trauma, autoimmune disorders, previous abdominal surgery, coexisting
malignancies moslty urogenital or gastrointestinal lymphomas [1, 2, 10].Establishing the diagnosis of SM is both a
clinical and histologic challenge. Clinical presentations are nonspecific and
in common with numerous other diseases. Patients with SM may present with
intestinal obstruction or ischemia, abdominal pain or distension, abdominal
mass, weight loss, fatigue, fever of unknown origin, protein-losing enteropathy
with diarrea, and minimal change nephropathy [11–14]. SM may be
totally asymptomatic, incidentally discovered on CT performed for other
reasons. Some Authors described concomitant SM and bile ducts fibrosis
simulating Klatskin’s tumor [15], SM involving the pancreas mimicking
pancreatic malignancy [6], and SM and inflammatory pseudotumor
simulating gastric lymphoma or linitis plastica [16]. The duration of
symptoms can range from days to 10 years (average 12 months) [9].Differential diagnosis take into account
mesenteric lipomas and liposarcoma, but radiographic tools (contrast studies
and CT or MRI [17]), even if very
useful in the detecting of the mass, can give only a suspicion of this
pathologic entity, because they provide nonspecific appearances, so the
diagnosis can only be obtained by histology. A pseudoascess resulting from a
diverticular diseases could be ruled out because of the absence of complicated
sigmoid diverticula and the absence of septic findings.SM has three modes of progression: partial or
complete resolution of the inflammatory process, a nonprogressive course, or an
aggressive course, characterized by a progressive fibrosis. That can cause
shortening of the mesentery and compression of mesenteric vessels and then
thrombosis with secondary variceal bleeding, ischemia or life-threatening
intestinal obstruction or ureteric obstruction with peritonitic or uremic
status. In our case colonoscopy found ischemic mucosal lesions, probably due to
the compression of terminal colic vessels by the fibrotic process. SM usually
has a bening course with a favorable outcome [4, 9] and spontaneous
resolution has been reported [6], but there are not identified
prognostic factors to predict the kind of progression. It has been suggested
that colonic forms have a more aggressive course and require surgical treatment
more often than other forms [5].There is not any specific treatment for SM. Many
medical modalities—including corticosteroids, colchicines,
immunosuppressive drugs, and progesterone—have been used with varying degrees of success
[8, 11, 18–22]. We think that complete laparotomic surgical resection
is mandatory in presence of complications as obstructions and vascular
involvement, but surgery has to be attempted also in order to allow a definite
diagnosis by the histology and to avoid the risk of coexisting malignancy, that
is hard to rule out in case of endoscopic or laparoscopic biopsies.



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*Source: 176793-2009-04-12.xml*