INTRODUCTION — Sclerosing mesenteritis is a rare, non-neoplastic inflammatory and fibrotic disease that affects the mesentery. Sclerosing mesenteritis can affect the integrity of the gastrointestinal lumen and mesenteric vessels by a mass effect. Sclerosing mesenteritis can result in a variety of gastrointestinal and systemic manifestations, including abdominal pain, nausea and vomiting, diarrhea, weight loss, and fever [1-5]. This topic will review the epidemiology, etiology, clinical manifestations, diagnosis, and management of sclerosing mesenteritis.
TERMINOLOGY — Sclerosing mesenteritis is often used as an umbrella term for a spectrum of idiopathic primary inflammatory and fibrotic processes that affect the mesentery [6,7]. Several terms have been used to describe this process based on the degree of inflammation and fibrosis; these include mesenteric lipodystrophy (with a predominance of fat necrosis) and sclerosing mesenteritis or mesenteric fibrosis (with a predominance of fibrosis) (table 1). Patients usually have a range of pathologic findings, with varying components of inflammation, fibrosis, and fat necrosis, although usually one feature predominates at a given time. Histologic progression has only rarely been documented [8]. It is quite likely that these features represent different points in the natural history of the underlying process, with adipocyte necrosis (mesenteric lipodystrophy) evolving into a chronic inflammatory state (mesenteric panniculitis), and finally to fibrosis (sclerosing mesenteritis).
EPIDEMIOLOGY — Sclerosing mesenteritis appears to be rare, and a significant proportion of patients are asymptomatic. In one autopsy series, the prevalence of sclerosing mesenteritis was one percent [9]. In a prospective evaluation of over 7000 consecutive abdominal computed tomography examinations, the frequency of sclerosing mesenteritis was 0.6 percent [10]. In another study of 613 consecutive unselected patients undergoing multidetector computed tomography, the frequency of mesenteric panniculitis was 7.8 percent [11]. Although sclerosing mesenteritis has been reported in persons as young as three years of age, it is diagnosed most commonly in the fifth to seventh decades of life, with a median age of 65 years [12,13]. The low prevalence in childhood and adolescence may be attributable to a smaller amount of mesenteric fat [14,15]. While most studies have found that the prevalence of sclerosing mesenteritis is higher in men, this has not been consistently demonstrated [7,10,12,13].
ETIOLOGY AND PATHOGENESIS — The pathogenesis of sclerosing mesenteritis remain unclear, although several mechanisms have been postulated.
●Abdominal surgery or abdominal trauma – It is hypothesized that sclerosing mesenteritis results in genetically predisposed individuals who have abnormal responses to healing and repair of connective tissue in response to trauma [5,7,16]. In a systematic review of the published literature, previous abdominal surgery or abdominal trauma was described in almost 30 percent of patients [13]. In one series of 92 patients with sclerosing mesenteritis, 38 patients (41 percent) had prior abdominal surgery, including cholecystectomy, appendectomy, hysterectomy, and colectomy [12]. Other studies, however, have not found an association with prior abdominal surgery or trauma [17,18]. Sclerosing mesenteritis has been reported in association with both acute abdominal injury and chronic repetitive trauma (eg, pneumatic jackhammer) and inflammation (eg, occult ileal perforation) [19,20]. The use of powdered surgical gloves has also been implicated in the development of abdominal fibrosis as a precursor to sclerosing mesenteritis [12].
●Autoimmunity – Sclerosing mesenteritis has been reported in association with a number of immune-mediated conditions, including Riedel thyroiditis, primary sclerosing cholangitis, retroperitoneal fibrosis, and orbital pseudotumor [13,21]. In addition, it has rarely been found as part of the initial presentation with autoimmune hemolytic anemia, minimal change nephropathy, systemic lupus erythematosus, relapsing polychondritis, multifocal fibrosclerosis, limited systemic sclerosis, and celiac-associated T-cell lymphoma [12,22-28]. A possible autoimmune etiology is also supported by a clinical response to immunomodulatory medications including glucocorticoids, azathioprine, and cyclophosphamide [29-33]. (See 'Approach to management' below.)
One series and case reports have described an association with elevated serum IgG4 and/or autoimmune pancreatitis in some patients, suggesting a possible role for IgG4-related immunopathologic processes in the development of sclerosing mesenteritis [12,15]. However, in one of the author’s experience, underlying IgG4 disease, whether measured by serum levels or tissue staining, appears to be rare [34].
●Paraneoplastic syndrome – Among patients with sclerosing mesenteritis, an underlying malignancy has been reported from 1 to 75 percent [1,2,7,10,13,35]. Non-Hodgkin lymphoma is the most commonly associated malignancy, however, others include breast cancer, carcinoid, melanoma, squamous carcinoma and adenocarcinoma of the lung, renal carcinoma, multiple myeloma, hepatocellular carcinoma, prostate adenocarcinoma, ovarian carcinoma, endometrial carcinoma, cervical carcinoma, angiosarcoma, and gastrointestinal adenocarcinomas [2,10,35,36]. While it has been hypothesized that sclerosing mesenteritis represents a nonspecific response to an underlying malignancy and is a paraneoplastic syndrome, other studies have not demonstrated an association [18,37].
●Ischemia and infection – A process mimicking sclerosing mesenteritis has been replicated in laboratory animals by a variety of methods, such as interference with the mesenteric vascular supply and injection of bacteria and bacterial toxins into the mesentery. A possible infectious etiology is consistent with case reports of sclerosing mesenteritis in patients with a history of typhoid fever, dysentery, tuberculosis, syphilis, malaria, influenza, and rheumatic fever [38].
CLINICAL PRESENTATION
Clinical features — Approximately 10 to 15 percent of patients with sclerosing mesenteritis are asymptomatic or have minimal symptoms [10,39].
The most common presenting features are abdominal pain (30 to 70 percent), systemic symptoms including fever, malaise and weight loss (20 to 23 percent), and altered bowel habits with either constipation or diarrhea (20 percent) [1,7,12]. Based on the severity, the duration of the symptoms varies from days to years prior to the diagnosis [1].
An abdominal mass can be palpated in 35 to 50 percent of patients. Masses tend to be deep seated and poorly defined [3,4,7,12,13]. Other findings include abdominal tenderness in approximately one-third of cases and distension in approximately 10 to 15 percent. Signs of peritoneal inflammation and ascites (usually chylous) are rare.
Patients may also have signs and symptoms attributable to associated conditions, such as underlying malignancy (eg, pleural effusion, fever, edema due to protein-losing enteropathy, hemolytic anemia, jaundice due to biliary obstruction) [22,23,40-45]. (See 'Etiology and pathogenesis' above.)
Complications — Patients with sclerosing mesenteritis can present with symptoms associated with complications. These complications include:
●Bowel obstruction (24 percent) (see "Etiologies, clinical manifestations, and diagnosis of mechanical small bowel obstruction in adults", section on 'Clinical presentations' and "Large bowel obstruction", section on 'Clinical presentations').
●Obstructive uropathy/renal failure (24 percent).
●Chylous ascites (14 percent) (see "Evaluation of adults with ascites", section on 'Clinical manifestations').
●Chronic mesenteric ischemia (3 percent) [12] (see "Chronic mesenteric ischemia", section on 'Clinical presentations').
Laboratory findings — The erythrocyte sedimentation rate and C-reactive protein level may be elevated in approximately 80 percent of patients [46]. Other nonspecific abnormalities include anemia (16 percent) and hypoalbuminemia (5 percent) [13]. (See 'Monitoring response to treatment' below.)
Incidental imaging findings — Abdominal radiographs, barium enema, and ultrasound are not diagnostic for sclerosing mesenteritis. Plain radiographs can demonstrate signs of mechanical obstruction of the small bowel, colon, or both. Barium enema of the gastrointestinal tract may demonstrate fixation, angulation, thumbprinting, separation, tethering of the bowel, and concentric bowel strictures with tapered, serrated edges [47]. An abdominal ultrasound may reveal a focal mass lesion [48].
Abdominal computed tomography is the imaging modality of choice but has low specificity for sclerosing mesenteritis. (See 'Diagnostic imaging' below.)
DIAGNOSIS
General approach — Sclerosing mesenteritis is rare and is usually discovered incidentally on abdominal imaging for evaluation of nonspecific abdominal or systemic symptoms (eg, abdominal pain, altered bowel habits, fever, or weight loss) [10,39]. In a patient with these abdominal or systemic symptoms, a presumptive diagnosis of sclerosing mesenteritis can be based on abdominal computed tomogram findings of a fat ring or halo sign and pseudocapsule. However, a definitive diagnosis of sclerosing mesenteritis requires histologic evaluation to rule out other etiologies. A laparoscopy or laparotomy is usually necessary to obtain tissue. A significant proportion of image-guided percutaneous biopsies are nondiagnostic because fine-needle aspiration specimens often lack sufficient architectural representation to exclude malignancy [49]. (See 'Differential Diagnosis' below.)
Pathologic confirmation should be obtained in all cases of suspected sclerosing mesenteritis with a mass lesion or pathologic appearing lymphadenopathy. However, the role of biopsy in patients with only mesenteric inflammation (misty mesentery) is controversial. We do not pursue a biopsy for a definitive diagnosis in such cases as the risks of biopsy outweigh the benefits. (See 'Diagnostic imaging' below.)
Diagnostic imaging — Contrast-enhanced abdominal computed tomography (CT) scan is the most sensitive imaging modality for detecting sclerosing mesenteritis. The CT appearance of sclerosing mesenteritis varies depending upon the extent and severity of inflammation and fibrosis [10,12]. However, many of the radiologic features are nonspecific. (See 'Differential Diagnosis' below.)
●Soft tissue mass – Sclerosing mesenteritis usually presents as a soft tissue mass in the root of the small bowel mesentery. [12]. Mass lesions may be homogeneous (more fibrotic lesions) or heterogeneous (more inflammatory). In one large series, focal lesions ranged from 1 to 40 cm in size, with a mean of 10 cm [7] Focal infiltration may also occur in the region of the pancreas, simulating a primary pancreatic malignancy.
●Fat ring and tumor pseudocapsule – Fat ring (or halo) sign and tumor pseudocapsule are generally considered to be specific for mesenteric panniculitis [21,50-55], although these findings may also be seen in cases of malignancy masquerading as mesenteric panniculitis [56]. The fat ring or halo sign describes the preservation of the densitometric values of fat nearest the mesenteric vessels (image 1) [21,50-55]. A tumor pseudocapsule, seen in up to 60 percent of patients, refers to the finding of a hyperattenuated stripe partly surrounding the inflammation.
●Vascular abnormalities – Vascular displacement, encasement, or thrombosis may be seen [21,50-55]. Multidetector CT with three-dimensional volume rendering can provide information about the relationship between mesenteric mass lesions and surrounding vasculature [57].
●Calcifications – Calcifications are present within approximately 20 percent of lesions and probably result from fat necrosis. Cystic components may be present, possibly from focal necrosis due to vascular obstruction. Lymphadenopathy (mesenteric or retroperitoneal) is present in 20 to 40 percent of patients [50,58].
●Misty mesentery – Misty mesentery has been used to describe the finding of increased attenuation of mesenteric fat with small lymph nodes but without evidence of a discrete mass [59,60]. The increased attenuation is due to infiltration by inflammatory cells, fluid (edema, blood, lymph), tumor, or fibrosis. Thus, it is not specific for sclerosing mesenteritis, because hemorrhage, edema, or malignancy (particularly lymphoma) can present in an identical fashion.
Magnetic resonance imaging has not been extensively studied in patients with sclerosing mesenteritis, although the findings appear to be similar to those on CT [61-64]. Positron emission tomography scan cannot reliably differentiate sclerosing mesenteritis from involvement of the mesentery with tumor in patients with cancer and therefore does not have a role in the evaluation of patients with sclerosing mesenteritis [65,66].
Pathology — Although gross findings are variable, three general patterns of mesenteric thickening have been observed [2,7]:
●Type I (42 percent of cases) – diffuse mesenteric thickening
●Type II (32 percent of cases) – a single discrete mass
●Type III (26 percent of cases) – multiple discrete mass lesions
The pattern of mesenteric thickening has not been associated with response to therapy or prognosis, so its clinical application is limited.
The most consistent histologic findings of sclerosing mesenteritis are fibrosis and chronic inflammation [7]. Granulomas are generally not part of the histologic spectrum but may be present in patients with a history of trauma or foreign bodies.
Flow cytometry is used if lymphoma cannot be excluded on histologic evaluation. Immunohistochemical staining for CD117/c-kit, beta catenin, and smooth muscle actin has been proposed for distinguishing sclerosing mesenteritis from gastrointestinal stromal tumors (GIST) and mesenteric fibromatosis [67]. Unlike GIST and mesenteric fibromatosis, sclerosing mesenteritis does not stain for CD117/c-kit and beta catenin, respectively, but retains staining for smooth muscle actin. (See "Clinical presentation, diagnosis, and prognosis of gastrointestinal stromal tumors".)
DIFFERENTIAL DIAGNOSIS — The differential diagnosis of sclerosing mesenteritis is broad and includes other processes that can affect the mesentery (table 2) [1-4,6,7,21,51,68-73]. The most common mimics are lymphoma, mesenteric carcinomatosis, carcinoid tumor, mesenteric fibromatosis, and mesenteric edema. Mesenteric edema can be caused by a number of conditions, including hypoalbuminemia, cirrhosis, congestive heart failure, and trauma.
The following features can help narrow the differential diagnosis:
●Non-Hodgkin lymphoma (NHL) may present as a nodal mass in the mesentery. However, features supportive of NHL include the presence of retroperitoneal lymphadenopathy, splenomegaly and lack of tumoral calcification. In addition, the fat ring that can be seen in sclerosing mesenteritis is absent in NHL. (See "Clinical presentation and diagnosis of primary gastrointestinal lymphomas" and 'Diagnostic imaging' above.)
●Neuroendocrine tumors may be associated with a misty mesentery and poorly defined mesenteric mass lesions, which arise in the setting of a desmoplastic tumor reaction. However, the presence of focal bowel lesions and liver lesions supports the diagnosis of carcinoid. (See "Diagnosis of carcinoid syndrome and tumor localization", section on 'Computed tomography'.)
●Peritoneal carcinomatosis is usually associated with ascites and multiple enhancing mesenteric, peritoneal, and/or omental nodules [56]. (See "Malignancy-related ascites", section on 'Imaging tests'.)
●Mesenteric fibromatosis (desmoid tumors) are tumor-like fibromatoses that are most commonly found in patients with familial adenomatous polyposis (FAP). These lesions can be distinguished from sclerosing mesenteritis on the basis of a paucity of inflammation and a tendency to involve the bowel muscularis propria. In addition, desmoid tumors tend to be multifocal and commonly recur following resection. Desmoids also lack the dense sclerosis more commonly found in sclerosing mesenteritis. (See "Desmoid tumors: Epidemiology, molecular pathogenesis, clinical presentation, diagnosis, and local therapy", section on 'Clinical presentation and diagnosis'.)
The differential diagnosis of abdominal pain is discussed in detail separately. (See "Causes of abdominal pain in adults".)
NATURAL HISTORY — The natural history of sclerosing mesenteritis is not well understood in part because of the rarity of this condition, the disparate nomenclature used in the literature, and lack of adequate follow-up. Although there are case reports of fatalities and patients with aggressive disease phenotypes, the breadth of clinical experience suggests a benign, stable, or slowly progressive course in approximately 80 percent of patients [11]. Cases of spontaneous regression have been reported, with times to resolution of the abdominal mass ranging from a few weeks to over a decade [1,74].
Approximately 20 percent of patients with sclerosing mesenteritis develop complications [7,13]. Fulminant cases of sclerosing mesenteritis have been reported and are largely due to complications of intestinal obstruction [75]. Other complications include mesenteric vascular occlusion (both arterial and venous), chylous ascites, and adverse effects from medications used to treat sclerosing mesenteritis. (See 'Complications' above and 'Nonobstructive symptoms' below.)
APPROACH TO MANAGEMENT — There is no uniformly recognized standard therapy for sclerosing mesenteritis. Our approach to management is based on the type and severity of symptoms (algorithm 1).
Whom to treat — The primary goal of therapy is the relief of symptoms. Therapy has not been shown to clearly improve prognosis or prevent progression or the development of complications. Patients who present with asymptomatic disease are likely to remain asymptomatic during follow-up and do not require treatment. In fact, only 1.1 to 6.1 percent of patients in imaging series are estimated to require treatment directed at sclerosing mesenteritis [5,10,21].
Therapy should be offered to patients with symptoms of sclerosing mesenteritis or its complications (eg, small bowel obstruction, chylous ascites and chronic mesenteric ischemia). (See 'Natural history' above and 'Clinical features' above and 'Obstructive symptoms' below.)
Pretreatment considerations — We typically perform the following studies prior to initiating therapy:
●Complete blood count
●Erythrocyte sedimentation rate and C-reactive protein
●Blood glucose
●Urinalysis
●Blood urea nitrogen and serum creatinine
●Liver tests including aminotransferases, alkaline phosphatase, and bilirubin
In patients who will be starting azathioprine, it is prudent to screen patients for mutations in the thiopurine methyltransferase (TPMT) gene that causes TPMT deficiency. One in 300 individuals are homozygous for a mutant allele and have very low or absent enzyme levels. These patients should not receive azathioprine because they cannot metabolize the drug and may develop life-threatening bone marrow suppression. (See "Thiopurines: Pretreatment testing and approach to therapeutic drug monitoring for adults with inflammatory bowel disease".)
Specific interactions with other medications may be determined using the drug interactions program (Lexicomp drug interactions) included with UpToDate. This tool can be accessed from the Drug Interactions link in the top right corner of your browser window in UpToDate online, or through the individual drug information monographs in the section "Drug Interactions."
Obstructive symptoms — Patients with bowel obstruction are managed conservatively with nonoperative management when feasible. Surgical bypass may be indicated to alleviate symptoms in those whose symptoms are dominated by focal intestinal obstruction [1-4,76]. In the vast majority of cases, complete surgical resection is impossible because of associated vascular compromise and disease extent. (See "Management of small bowel obstruction in adults" and "Large bowel obstruction".)
Patients with symptoms of chronic mesenteric ischemia due to obstructed mesenteric arteries or veins require revascularization. However, endovascular revascularization is possible only in a minority of patients due to the length or distal arterial location of the stenosis. Open surgical techniques for mesenteric revascularization are rarely feasible due to the disease extent. Radiation therapy has had equivocal success [8,77]. (See "Chronic mesenteric ischemia", section on 'Management'.)
Surgery does not cure sclerosing mesenteritis. In one study, 10 percent of patients who underwent surgery required no additional treatment [12]. Recurrent disease can manifest by radiologic findings in patients with clinical symptoms. In patients with persistent or recurrent symptoms following surgery, we suggest medical management similar to patients with nonobstructive symptoms. (See 'Initial treatment' below.)
Nonobstructive symptoms
Initial treatment — We use glucocorticoids (prednisone 40 mg daily) and tamoxifen (10 mg twice daily) as initial medical therapy in patients with symptomatic sclerosing mesenteritis. In patients with symptomatic improvement at three months, prednisone is tapered gradually over three months. Tamoxifen is continued indefinitely in patients with sustained symptomatic improvement [5] (algorithm 1). A number of immunosuppressive agents have been used in an attempt to stabilize the disease. However, there are limited data from case series to support their use in controlling symptoms of sclerosing mesenteritis, and these agents have not been directly compared. Alternative treatment approaches may be required for patients who cannot tolerate tamoxifen due to side effects or have contraindications to tamoxifen. (See 'Alternative approaches and refractory disease' below.)
●Glucocorticoids – Glucocorticoids alone, and in combination with azathioprine or tamoxifen, has been associated with symptomatic improvement [12,29,31-33]. Patients with the greatest inflammatory component, as demonstrated by the acuity of presentation with fever, weight loss, malaise, elevated erythrocyte sedimentation rate, and prominent inflammation on biopsy, appear to be the most responsive. Due to frequent steroid-related side effects, long-term treatment with glucocorticoids is not recommended. (See 'Duration of therapy in responders' below.)
●Hormonal therapy – Tamoxifen is a selective estrogen receptor modulator. A proposed mechanism of benefit from tamoxifen is the inhibition of fibroblast TGF-beta1 production [78]. A response to hormonal therapy with tamoxifen and rarely progesterone has been described in case reports [79,80]. In one series of 92 patients with sclerosing mesenteritis, in which 20 patients were treated with combination therapy with tamoxifen plus glucocorticoids, symptomatic improvement was reported in 12 patients (60 percent) within 12 to 16 weeks [12]. Among eight patients without improvement, persistent symptoms and progressive symptoms were reported in six (30 percent) and two (10 percent), respectively. Tamoxifen is associated with an increased risk of uterine cancer. Other side effects associated with the use of tamoxifen include hot flashes, vaginal discharge, menstrual irregularities, sexual dysfunction, and venous thromboembolism. (See "Managing the side effects of tamoxifen and aromatase inhibitors".)
Monitoring response to treatment — Response to therapy is assessed by symptom improvement. Erythrocyte sedimentation rate and C-reactive protein level are neither sensitive nor specific, and treatment decisions are generally based on symptoms alone [46]. Radiologic improvement occurs in the minority of patients and often does not correlate with symptomatic response to treatment. We therefore do not perform follow-up abdominal CT scans unless clinically warranted.
There are limited data on the predictors of treatment response in patients with sclerosing mesenteritis. In a systematic review of 192 reported cases of sclerosing mesenteritis, symptom duration of greater than one month, the presence of an underlying autoimmune disorder, or low serum protein were associated with a poor response to medical treatment that predominantly consisted of glucocorticoids [13]. By contrast, patients with abdominal tenderness or leukocytosis at presentation were more likely to have a good response to treatment.
Duration of therapy in responders — In patients with symptomatic response to initial treatment with prednisone (40 mg daily for three months) and tamoxifen, we gradually taper prednisone over three months. We continue tamoxifen indefinitely in patients who respond and are tolerating treatment.
Alternative approaches and refractory disease — In patients whose symptoms do not respond to tamoxifen, who cannot tolerate tamoxifen due to side effects, or who have contraindications to tamoxifen, we use azathioprine or pentoxifylline (algorithm 1). Given the side-effect profile of cyclophosphamide, we reserve its use for patients that are refractory to azathioprine and pentoxifylline. We use thalidomide in patients with sclerosing mesenteritis who do not respond to other treatment options. Data to support these agents are limited to small case series and studies comparing them are lacking.
●Azathioprine – We use azathioprine (2 to 2.5 mg/kg/d) in patients who are refractory to tamoxifen. However, it may be used as an alternative to tamoxifen (algorithm 1). The major limitation of azathioprine is the slow response to treatment. Combination treatment with glucocorticoids followed by azathioprine offers the advantage of relatively rapid improvement while avoiding the long-term consequences of glucocorticoid treatment. Side effects include bone marrow suppression, infections, nausea, pancreatitis, and an increased risk of lymphoma and skin cancers.
In an observational study that included 92 patients with sclerosing mesenteritis, treatment included medical therapy alone in 24 patients, surgery alone in 12, surgery followed by medical therapy in 8, and 48 patients (52 percent) received no treatment [12]. Medical treatment consisted of treatment with one or more of the pharmacologic agents for a treatment duration that ranged from 4 to 36 months. Agents used included tamoxifen, prednisone, budesonide, colchicine, azathioprine, methotrexate, and thalidomide. Symptomatic improvement was noted in 12 of 20 patients (60 percent) treated with tamoxifen in combination with prednisone. Of the 12 patients treated with non-tamoxifen-based regimens, one of two patients treated with prednisone, azathioprine, and colchicine responded to treatment. Two patients treated with other regimens (prednisone, azathioprine, and thalidomide; and prednisone and colchicine) had persistent/progressive disease.
●Pentoxifylline – Pentoxifylline has weak anti-inflammatory and possibly antifibrotic properties. It can be used as an alternative to azathioprine and in patients refractory to azathioprine. In one of the author’s experience of 13 patients with sclerosing mesenteritis treated with pentoxifylline for a varying duration, six (46 percent) had at least partial symptom improvement [34].
●Cyclophosphamide – Cyclophosphamide is an alkylating agent that reduces proliferation of both B and T cells. Cyclophosphamide has several serious potential side effects.
A response to oral cyclophosphamide was described in two patients, including one who had not responded to glucocorticoids [30]. Prior to the initiation of therapy, both had a progressive downhill course characterized by prominent systemic symptoms. Initiation of cyclophosphamide (2 mg/kg) resulted in clinical remission for up to 30 months. One of the two patients had complete resolution of the mass at surgical exploration. (See "General toxicity of cyclophosphamide in rheumatic diseases".)
●Thalidomide – Thalidomide has anti-inflammatory, immunomodulatory, and antiangiogenic properties. In an open-label pilot study of five patients with symptomatic mesenteric panniculitis, treatment with thalidomide (200 mg/day for 12 weeks) was safe and well tolerated [46]. Although there was no radiologic improvement in post-treatment CT scans, four of five patients experienced an improvement or resolution in symptoms.
●Colchicine – The use of colchicine in sclerosing mesenteritis is controversial. A case report described successful transition to colchicine (1 mg daily) for maintenance therapy in a patient who had responded clinically to glucocorticoids [81]. In one case series, colchicine with prednisone was reported to be as effective as prednisone plus tamoxifen, although the number of patients treated was small [82]. However, in the authors' experience, most patients either do not respond to colchicine or do not tolerate it due to gastrointestinal side effects.
SUMMARY AND RECOMMENDATIONS
●Sclerosing mesenteritis is a rare, non-neoplastic inflammatory and fibrotic disease that affects the mesentery. Sclerosing mesenteritis can affect the integrity of the gastrointestinal lumen and mesenteric vessels by a mass effect. Sclerosing mesenteritis encompasses a spectrum of idiopathic primary inflammatory and fibrotic processes that affect the mesentery. (See 'Introduction' above and 'Terminology' above.)
●The clinical presentation ranges from an asymptomatic incidental finding on abdominal imaging to abdominal and systemic symptoms (eg, abdominal pain, altered bowel habits, fever, weight loss) to complications such as intestinal obstruction. Laboratory markers of inflammation (erythrocyte sedimentation rate and C-reactive protein) may be elevated. (See 'Clinical presentation' above.)
●Sclerosing mesenteritis is usually discovered incidentally on abdominal imaging for evaluation of nonspecific abdominal or systemic symptoms. A presumptive diagnosis of sclerosing mesenteritis can be based on abdominal computerized tomogram findings of a fat ring or halo sign and pseudocapsule (image 1). However, a definitive diagnosis of sclerosing mesenteritis requires histologic evaluation to rule out other etiologies. (See 'Diagnosis' above.)
●Approximately 20 percent of patients with sclerosing mesenteritis develop complications. Fulminant cases of sclerosing mesenteritis have been reported and are largely due to complications of intestinal obstruction. Other complications include mesenteric vascular occlusion (both arterial and venous), chylous ascites, and adverse effects from medications used to treat sclerosing mesenteritis. (See 'Natural history' above.)
●Management is based on the presence of symptoms due to sclerosing mesenteritis or its complications (algorithm 1). Patients with asymptomatic disease do not require treatment. The primary goal of therapy is the relief of symptoms. In patients who are symptomatic, we suggest a trial of medical therapy (Grade 2C). We use glucocorticoids in combination with tamoxifen as first-line therapy. In patients who fail to respond to tamoxifen, we use azathioprine or pentoxifylline. Given the side-effect profile of cyclophosphamide, we reserve its use for patients that are refractory to azathioprine and pentoxifylline. The role of surgery in sclerosing mesenteritis is limited to selected patients with obstructive complications. (See 'Approach to management' above.)
