Is mesenteric panniculitis truely a paraneoplastic phenomenon? A matched pair analysis

A review of 17 cases of mesenteric panniculitis in Zhengzhou Ninth People's Hospital in China

PURPOSE

Mesenteric panniculitis (MP) represents the uncommon, benign and chronic inflammatory disorder affecting the mesenteric adipose tissues. Its etiology, diagnosis and treatment remain unnoticed. Our report focused on shedding more lights on this condition.

PATIENTS AND METHODS

Seventeen MP patients were identified by searching the electronic medical record system in the Zhengzhou Ninth People's Hospital using the search terms "Mesenteric panniculitis" from October 2015 to March 2023. All cases were diagnosed with MP through computed tomography (CT). Their clinical features and treatments were analyzed.

RESULTS

There were altogether 17 cases enrolled for this analysis. The male to female ratio was 8:9, and the median age at diagnosis was 64 (range: 37-96) years. There were 15 patients (88.2%) showing abdominal pain to varying degrees. The proportions of symptoms of nausea, vomiting and fever were 23.5%, 23.5% and 41.2%, respectively. Neoplastic disease was present in 3 patients (17.6%). Meanwhile, 9 patients (52.9%) had gallstones, 3 (17.6%) had cholecystitis and 1 (5.9%) had gallbladder polyps. Six patients (35.3%) received antibiotics treatment only and 1 (5.9%) received oral antibiotics and prednisone. One patient (5.9%) received antibiotics followed by prednisone treatment, because the symptoms were significantly relieved after antibiotic treatment, while the disease recurred soon after, and the symptoms improved again after prednisone treatment. The abdominal pain in 9 patients (52.9%) was relieved spontaneously. Two patients (11.8%) died, including one due to respiratory failure caused by pneumonia and the other one because of pancreatic cancer with lung and liver metastases.

CONCLUSION

MP is a poorly understood chronic inflammatory disease. Patients often have abdominal pain as the main symptom, accompanied by comorbidities in the gallbladder, and the prognosis is usually good after correct diagnosis and treatment, Therefore, the present report aims to promote the awareness among clinicians of patients with non-classic abdominal symptoms, so as to avoid misdiagnosis or missed diagnosis.

Sclerosing mesenteritis following immune checkpoint inhibitor therapy

PURPOSE

Sclerosing mesenteritis (SM), a fibroinflammatory process of the mesentery, can rarely occur after immune checkpoint inhibitor (ICI) therapy; however, its clinical significance and optimal management are unclear. We aimed to assess the characteristics and disease course of patients who developed SM following ICI therapy at a single tertiary cancer center.

METHODS

We retrospectively identified 12 eligible adult cancer patients between 05/2011 and 05/2022. Patients' clinical data were evaluated and summarized.

RESULTS

The median patient age was 71.5 years. The most common cancer types were gastrointestinal, hematologic, and skin. Eight patients (67%) received anti-PD-1/L1 monotherapy, 2 (17%) received anti-CTLA-4 monotherapy, and 2 (17%) received combination therapy. SM occurred after a median duration of 8.6 months from the first ICI dose. Most patients (75%) were asymptomatic on diagnosis. Three patients (25%) reported abdominal pain, nausea, and fever and received inpatient care and corticosteroid treatment with symptom resolution. No patients experienced SM recurrence after the completion of corticosteroids. Seven patients (58%) experienced resolution of SM on imaging. Seven patients (58%) resumed ICI therapy after the diagnosis of SM.

CONCLUSIONS

SM represents an immune-related adverse event that may occur after initiation of ICI therapy. The clinical significance and optimal management of SM following ICI therapy remains uncertain. While most cases were asymptomatic and did not require active management or ICI termination, medical intervention was needed in select symptomatic cases. Further large-scale studies are needed to clarify the association of SM with ICI therapy.

Acute Epigastric Pain: Unexpected Urologic Findings on Computed Tomography

Mesenteric panniculitis is a relatively common condition encountered on cross-sectional imaging and is mostly asymptomatic. We present one such case where an underlying malignancy was brought to forefront due to associated mesenteric panniculitis presenting as acute abdomen.

Mesenteric panniculitis is associated with cardiovascular risk-factors: A case-control study

BACKGROUND

This study evaluated the prevalence of cardiovascular risk-factors in patients with mesenteric panniculitis.

AIMS

To determine whether cardiovascular risk-factors and mesenteric panniculitis are associated.

METHODS

Retrospective, matched case-control study of patients referred to Meir Medical Center, Israel, 2014-2019, who underwent computerized tomography scan, were diagnosed mesenteric panniculitis by radiologic criteria. They were compared to two, matched case-control groups: hospitalized patients without mesenteric panniculitis and the general population based on Israeli Ministry of Health surveys. Patients with active malignancy, IBD or significant intra-abdominal morbidity were excluded.

RESULTS

Of 376 patients with mesenteric panniculitis diagnosed by computerized tomography, 187 were included. Compared to hospital patients, they had higher incidence of dyslipidemia (77.5%/56.7%), hypertension (52.4%/40.6%), obesity (body mass index>30) (60.4%/30.5%) and nonalcoholic fatty liver disease (42.2%/16.6%). Similar differences were observed compared to the general population. In multivariable logistic regression, dyslipidemia, obesity, and nonalcoholic fatty liver disease were independent predictors for mesenteric panniculitis.

CONCLUSIONS

Patients with mesenteric panniculitis have more cardiovascular risk-factors compared to a case-control group and to the general population. This suggests that mesenteric panniculitis is clinically significant and may be part of the metabolic morbidity burden. This association should be further explored.

Sclerosing Mesenteritis: A Rare Cause of Abdominal Pain

Sclerosing mesenteritis (SM) is a rare inflammatory fibrotic disease of the small intestine mesenteric fat often discovered incidentally on a CT scan. Clinical manifestations depend on the mass effect on the viscera and vessels. The most common symptoms are abdominal pain, bloating, and nausea. SM occurs predominantly in Caucasian men, during the fifth to seventh decades of life. We present a 69-year-old woman with SM whose symptoms were thought to be from irritable bowel syndrome.

A 69-year-old female with a history of fibromyalgia presented with recurrent bouts of abdominal pain across her mid-abdomen lasting 30 minutes to an hour associated with nausea, alternating constipation and diarrhea with occasional mucus, and bloating. She used bismuth subsalicylate and ondansetron with temporary relief. Upper endoscopy and colonoscopy were unrevealing. Initially, she was felt to have irritable bowel. Later she presented with nausea and right upper quadrant pain and underwent cholecystectomy. When her pain recurred, the patient had a CT abdomen and pelvis which showed multiple sub-centimeter mesenteric lymph nodes with surrounding haziness and stranding in the root of the mesentery consistent with SM. The patient had a pannus biopsy showing fat necrosis that confirmed the diagnosis. She continued to have waxing and waning symptoms over several years and in the interim was diagnosed with melanoma limited to the skin. The patient had a particularly severe episode of abdominal pain prompting a repeat CT scan with a subsequent biopsy of an enlarged left para-aortic lymph node that revealed lymphoma.

Our patient’s diagnosis of SM was delayed as her symptoms were mistaken for irritable bowel syndrome. Worsening symptoms should alert clinicians to an alternate diagnosis such as SM. There are characteristic radiographic findings on CT scans and biopsy of the lesions. SM’s association with neoplastic diseases such as lymphoma, melanoma, colorectal, and prostate cancer is controversial, however, practitioners should be aware of this possibility and consider biopsy for any suspicious lesions.

CT features associated with underlying malignancy in patients with diagnosed mesenteric panniculitis: Mesenteric panniculitis: CT features associated with underlying malignancy

PURPOSE

The purpose of this study was to identify abdominal computed tomography (CT) features associated with underlying malignancy in patients with mesenteric panniculitis (MP).

MATERIALS AND METHODS

This single-institution retrospective longitudinal cohort study included patients with MP and a minimum 1-year abdominopelvic CT follow-up or 2-year clinical follow-up after initial abdominopelvic CT examination. Two radiologists, blinded to patients' medical records, conjointly reviewed CT-based features of MP. Electronic medical records were reviewed for newly diagnosed malignancies with the following specific details: type (lymphoproliferative disease or solid malignancy), location (possible mesenteric drainage or distant), stage, time to diagnosis. An expert panel of three radiologists and one hemato-oncologist, who were blinded to the initial CT-based MP features, assessed the probability of association between MP and malignancy based on the malignancy characteristics.

RESULTS

From 2006 to 2016, 444 patients with MP were included. There were 272 men and 172 women, with a median age of 64 years (age range: 25-89); the median overall follow-up was 36 months (IQR: 22, 60; range: 12-170). A total of 34 (8%) patients had a diagnosis of a new malignancy; 5 (1%) were considered possibly related to the MP, all being low-grade B-cell non-Hodgkin lymphomas. CT features associated with the presence of an underlying malignancy were the presence of an MP soft-tissue nodule with a short axis >10 mm (P < 0.0001) or lymphadenopathy in another abdominopelvic region (P < 0.0001). Associating these two features resulted in high diagnostic performance (sensitivity 100%; [95% CI: 57-100]; specificity 99% [95% CI: 98-100]). All related malignancies were identified.

CONCLUSION

Further workup to rule out an underlying malignancy is only necessary in the presence of an MP soft-tissue nodule >10 mm or associated abdominopelvic lymphadenopathy.

Colchicine as an Alternative First-Line Treatment of Sclerosing Mesenteritis: A Retrospective Study

BACKGROUND

Sclerosing mesenteritis is a rare condition characterized by chronic inflammation and fibrotic changes of the mesentery.

AIMS

To determine the long-term management and outcomes of patients with sclerosing mesenteritis.

METHODS

Patients with biopsy-proven sclerosing mesenteritis at the Mayo Clinic between January 2006 and December 2016 were identified. Clinical data were collected retrospectively.

RESULTS

One hundred and three patients were identified, median age 68.0 years (range 35.0-85.3). Most patients were symptomatic (87.4%) at presentation. Patients received no treatment (52.4%), medical therapy (42.7%) or surgery (4.9%) on initial diagnosis. The most common initial regimens were prednisone plus tamoxifen (41.9%), prednisone alone (23.3%), and prednisone plus colchicine (11.6%) with 55.6%, 57.2%, and 60% of patients improving, respectively, p = 0.85 for a difference in response rates. At least half of the patients responded to prednisone plus tamoxifen, prednisone plus colchicine, or prednisone alone at 6.0, 7.2, and 8.4 months, respectively. At a median follow-up of 45.6 months (95% CI 24.1-69.7), 65.4% of patients were receiving medical therapy. Of those receiving tamoxifen-based, steroid-based, or steroid-sparing regimens, 100%, 87.5%, and 77.8% had improved by their last follow-up appointment respectively, p = 0.15.

CONCLUSION

Prednisone plus colchicine has a similar efficacy to prednisone plus tamoxifen for the initial and long-term treatment of sclerosing mesenteritis. The majority of patients were initiated on medical therapy over the long term with most reporting symptomatic improvement within a year. Death from SM was rare.

Recognizing the Ultrasound Patterns of Mesenteric Panniculitis

ABSTRACT

Mesenteric panniculitis (MP) is a rare, benign, and nonspecific chronic fibrosing inflammation of the mesenteric adipose tissue. Abdominal pain is the most frequent presentation.The objective was to recognize ultrasound (US) features in MP. A retrospective 9-year review of computed tomography- (CT) or US-diagnosed cases of MP recorded in the radiology department was performed. The inclusion criteria included an US recorded in PACS imaging data base within 10 days before CT, to compare and evaluate the correlation of MP diagnosis.The prevalence of MP on CT was 2.8%. The 120 selected patients had an abdominal US 10 days before CT. Male-to-female ratio was 4:1. Fifty-three percent of MP was suggested by US. The US finding was increased volume with fatty mass in the mesentery root (98%). The fatty mesenteric mass had oval shape or convex anterior border in 94%, central abdominal location in 91%, and focal mesenteric increased echogenicity in 95%. Lateral bowel loop displacement was observed in 59%. Detection of lymph nodes was less frequent (55%).In conclusion, MP is an entity to be considered in the differential diagnosis of abdominal pain. Knowledge and recognition of the US findings of MP and central abdominal compression may improve detection during the abdominal US examination.

Mesenteric panniculitis does not confer an increased risk for cancers: A systematic review and meta-analysis

BACKGROUND

Mesenteric panniculitis (MP) is a non-specific, localized inflammation at the mesentery of small intestines which often gets detected on computed tomography. An association with malignant neoplasms remains unclear. We performed a systematic review and meta-analysis to examine the association of malignancy with MP.

METHODS

MEDLINE, EMBASE, Web of Science, and Cochrane databases were searched for articles published from inception to 2020 that evaluated the association of malignant neoplasms with MP in comparison with control groups. Using random-effects method, a summary odds ratio (OR) estimate with 95% confidence intervals for malignant neoplasms in MP was estimated.

RESULTS

Four case-control studies reporting data on 415 MP patients against 1132 matched-controls met inclusion criteria and were analyzed. The pooled OR for finding a malignant neoplasm in patients with MP was 0.907 (95% CI: 0.688-1.196; P = .489). The heterogeneity was mild and non-significant. Also, there was no heightened risk of any specific type of malignancy with MP. Three more case-series with unmatched-control groups (MP: 282, unmatched-controls: 17,691) were included in a separate analysis where the pooled OR of finding a malignant neoplasm was 2.963 (95% CI: 1.434-6.121; P = .003). There was substantial heterogeneity in this group.

CONCLUSION

This meta-analysis of matched controlled studies proves absence of any significant association of malignant neoplasms with MP. Our study also demonstrates that the putative association of malignancy with MP is mainly driven by uncontrolled studies or case-series.

[Incidental and "leave me alone" findings of the GI tract-part 2 : Intestinal wall and mesentery]

Due to the widespread use of computed tomography (CT) and magnetic resonance imaging (MRI) asymptomatic incidental findings of the gastrointestinal (GI) tract are increasingly being recognized. Incidental findings are frequently not part of the primary inquiry from referring physicians but it is obligatory to make a diagnosis and to stipulate the need for further clarification. A multitude of incidental findings in the intestinal lumen, in the intestinal wall and in the adjacent mesentery or subperitoneal space are shown in CT and MRI of the GI tract. The last part of the two-part review addresses the gastrointestinal incidental findings in the intestinal wall and the adjacent sections. Extramural incidental findings occur as mesenteric inflammation, tumors and cysts. Many of the findings can be classified as benign and as "leave me alone lesions" do not necessitate any further clarification but in contrast others need a definitive clarification. The most important incidental findings in the GI tract are systematically classified, illustrated and evaluated with respect to the clinical relevance, depending on the localization (e.g. stomach, small and large intestines).

Sclerosing Mesenteritis, a Rare Cause of Mesenteric Mass in a Young Adult: A Case Report

Sclerosing mesenteritis (SM) is a rare fibroinflammatory disorder that involves mesenteric adipose tissue, more frequently localized in the small intestine, with an insidious clinical presentation having symptoms related to mass effect, usually resulting in bowel obstruction, mesenteric ischemia, as well as rapid weight loss. We report a case of a 23-year-old male presenting with palpable abdominal mass, mesogastric pain, and a history of rapid weight loss, who underwent exploratory laparoscopy. A hemorrhagic and gelatinous nodular tumor mass of the mesentery was identified and the surgical procedure was converted to a laparotomic approach. Histologically, the mass was composed of a proliferation of bland-looking spindle cells with slightly eosinophilic cytoplasm and elongated normochromatic nuclei with mild nuclear atypia, haphazardly set in a collagenized stroma; fat necrosis and inflammatory cells (lymphocytes, plasma-cells, and histiocytes) were also evident. The diagnosis of sclerosing mesenteritis was made. Our case emphasizes that histology remains pre-eminent for a correct diagnosis of SM, as pre-operative radiological-based diagnosis is non-specific.

Association between mesenteric panniculitis and non-neoplastic disorders

PURPOSE

To assess the relationship between MP and coexisting non-neoplastic disorders.

METHODS

Consecutive abdominal computed tomography (CT) scans of 4674 patients were evaluated retrospectively for CT features of MP between January 2017 and January 2018. Clinical findings of patients were analyzed. Four control patients were selected from our cohort for each MP patient such that they matched for age, gender and CT protocol. Statistical analysis was performed using a t, Mann-Whitney U, χ², or Fisher's test.

RESULTS

976 patients were excluded from the study due to the exclusion criteria and finally, 102/3698 patients were diagnosed with MP (mean age = 57.2 ± 12.5 years, 52% male). On CT, a hyperattenuated fatty mass (120/120), subcentimeter lymph nodes (117/120), congregation of mesenteric vessels (82/120) within the mass, a fat halo sign (28/120) and a pseudocapsule (88/120) were seen at the mesentery.The intra-observer agreement was almost perfect for the fatty mass and lymph nodes and moderate or substantial for other CT features (p < 0.001). The most prominent disorders were metabolic syndrome (MetS) and urogenital diseases in MP (45%, 37%, respectively) and control groups (31%, 26%, respectively). Between groups, no significant differences were found in the history of abdominal surgery, gastrointestinal and autoimmune diseases (p-value range 0.064-0.663); however, significant differences were found in the rates of vascular, urogenital diseases and MetS (p-value range 0.012-0.036).

CONCLUSION

MetS and urolithiasis were significantly more common in patients with MP than in those without MP. Therefore, there may be a clinically relevant association between these disorders. MetS may be a risk factor for MP and urolithiasis, and treatment of metabolic disorders should be undertaken to prevent these diseases.

Mesenteric panniculitis mimicking early recurrence at end-of-treatment evaluation in malignant lymphoma: Differentiation by active surveillance with F-18 FDG PET/CT imaging

Mesenteric panniculitis is a relatively rare fibro-inflammatory condition of the mesentery. In acute phase, it demonstrates avid uptake on Fluorine-18 FDG PET/CT (PET/CT). Thorough assessment is needed to differentiate from viable or recurrent disease in patients with malignant lymphoma because it mimics active lymphomatous disease on PET/CT. In this article, 3 illustrative cases of malignant lymphoma are presented. PET/CT demonstrated new FDG-avid mesenteric lesions at the end-of-treatment evaluation while the original disease showed significant response. Early recurrence was initially suspected, but together with clinical course and findings, active surveillance was opted. Sequential follow-up PET/CTs showed various patterns of metabolic activity over time; it can persist for months or more, or metabolic activity can fluctuate over time. Eventually benignity was confirmed in these cases. These cases underscore the importance of interpretation with clinical context and awareness of chronological metabolic changes of mesenteric panniculitis to determine proper management.

Wuda granule, a traditional Chinese herbal medicine, ameliorates postoperative ileus by anti-inflammatory action

BACKGROUND

Postoperative ileus (POI) is a temporary disturbance in gastrointestinal motility following surgery, and intestinal inflammatory response plays a critical role in the pathogenesis of POI. Wuda granule (WDG), a gastrointestinal prokinetic Chinese herbal medicine, is prescribed to promote recovery of gastrointestinal function after abdominal surgery. However, it has remained unclear whether WDG shows anti-inflammatory effects in POI. In the present study, we investigated the effects of WDG in a rat POI model and attempted to clarify the detailed mechanisms of action.

METHOD

Experimental POI was induced in adult male SD rats by intestinal manipulation (IM). WDG were orally administered after surgery at the same points (6 h, 12 h, 18 h, 24 h). Histological changes of mesenterium, levels of cytokines, and CD68 and iNOS expression were determined in rats treated or not with WDG. We also investigated the transcriptome profile of rats treated with WDG in a POI model.

RESULTS

Experimental POI in rats was characterized by a marked intestinal and systemic inflammatory response. WDG significantly inhibited the infiltration of neutrophils and macrophages, reduced the levels of IL-6, and CRP, and inhibited protein expressions of CD68 and iNOS in mesentery. Comparison analysis showed that there are 1432 differentially expressed genes (DEGs) between the POI and CON sample, whereas 331 DEGs between the WDG -treated sample and the POI group. And 16 DEGs were shared by the POI vs CON and WDG vs POI groups, among which 6 hub genes associated with immune system processes were identified and verified.

CONCLUSIONS

WDG treatment ameliorates the impaired gastrointestinal motility in the rat model of POI through inhibiting the inflammatory response of mesentery.

A diagnostic dilemma: Pedunculated mesenteric lipodystrophy mimicking Meckel’s diverticulum. A case report and literature review

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Mesenteric lipodystrophy is a rare fibroinflammatory disease of unknown origin.

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The detection of mesenteric lipodystrophy is challenging and requires early clinical suspicion.

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Clinical and imaging findings can mimick other pathological conditions affecting the mesenteric fat tissue.

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Contrast enhanced CT is the most accurate imaging technique for diagnosing mesenteric lipodystrophy.

Introduction

Mesenteric lipodystrophy is a rare fibroinflammatory disease of unknown origin with clinical and radiological non specific findings.

Presentation of the case

The case of a 42-years-old man affected by a pedunculated mesenteric lipodystrophy mimicking Meckel’s diverticulum is reported. Clinical, imaging and histological findings are discussed.

Discussion

Mesenteric lipodystrophy affects the mesenteric fat of the abdomen with a typical diffuse thickening of the mesentery, nodular thickening of the mesenteric root and presence of mass-like lesions. Ultrasound (US) and Multiphasic Computed Tomography (CT) represent the main imaging tools used for diagnosis. Clinical and imaging findings can mimick other pathological conditions affecting the mesenteric fat tissue. Contrast enhanced CT is the most accurate imaging technique for diagnosing mesenteric lipodystrophy due to the high panoramicity and accuracy with multiplanar imaging. Multiphasic technique helps to characterize the lesion and to recognize vascular anatomy. Oral administration of iodinated contrast medium may help to assess the relationship with bowel loops. All these diagnostic elements are crucial for the surgical timing and approach.

Conclusions

Due to the heterogeneous mesenteric involvement, the nonspecific CT findings and the high number of diseases for differential diagnosis, the detection of mesenteric lipodystrophy is challenging and requires early clinical suspicion. An histological examination is always necessary.

Clinical and radiological features of mesenteric panniculitis: a critical overview

The mesenteric panniculitis is a rare form of inflammation that mainly involves the mesenteric adipose tissue. The etiology remains unknown and the disease has been associated with various conditions such as cancer, abdominal trauma, previous surgery, autoimmune diseases and obesity. Mesenteric panniculitis can be divided into two main groups: the mesenteric panniculitis with only the inflammation and degeneration of the mesenteric fat, and the retractile panniculitis, mainly fibrotic, with retraction of the surrounding structures. From a radiological point of view, there are two main signs: the fat ring sign, which is the presence of normal fat around vessels and lymph nodes, and the pseudocapsula around the lesion. In this paper, we present the imaging and clinical features of mesenteric panniculits with particular reference to the differential diagnosis and the possible etiological associations. (www.actabiomedica.it)

The Complex Relationship between Mesenteric Panniculitis and Malignancy - A Holistic Approach is Still Needed to Understand the Diagnostic Uncertainties

Mesenteric panniculitis is an idiopathic, localized inflammation involving the adipose tissue of the small bowel mesentery. The association of mesenteric panniculitis with malignancy, predominantly lymphomas, has been widely reported in the medical literature. In this review article, we will discuss the clinical guidelines in the diagnosis and management of mesenteric panniculitis and the clinical association between mesenteric panniculitis and malignancies.

[Misty mesentery : Mesenteric panniculitis and associated processes]

BACKGROUND

Sclerosing mesenteritis (SM) and mesenteric panniculitis are rare processes of the mesentery which pose a major clinical and imaging challenge. This review article attempts to introduce a systematic nomenclature to address typical symptoms, imaging and major differential diagnoses.

RESULTS

SM with its subtypes-mesenteric lipodystrophy, panniculitis and retractile mesenteritis-is a chronic process with a very diverse and heterogeneous clinical appearance. The typical radiological characteristics ("misty mesentery", increased lymph nodes, pseudocapsule and "fat halo") are also not very specific. A link between SM and malignant diseases is not proven, but there is controversial discussion. Therefore, if there are doubts about the diagnosis, further examinations and a biopsy are desired.

CONCLUSION

When diagnosing SM, "red flags", i. e. characteristics that are atypical for SM in imaging, should be considered. In case of ambiguous imaging, differential diagnostics should also consider malignant diseases and exclude them.

Sclerosing Mesenteritis

Sclerosing mesenteritis is a rare non-neoplastic disorder characterized by fat necrosis, chronic inflammation, and fibrosis typically of the small bowel mesentery. Our understanding of this disorder is limited by its rarity as well as inconsistent terminology used across the literature. While prior abdominal surgery or trauma, autoimmunity, infection, ischemia, and malignancy have been suggested to be involved in the pathogenesis of the disorder, it remains poorly understood. The clinical course of sclerosing mesenteritis is generally benign with a large proportion of patients diagnosed incidentally on imaging obtained for other indications. In a subset of patients, symptoms may arise from a mass effect on the bowel, lymphatics, or vasculature resulting in bowel obstruction, chylous ascites, or mesenteric ischemia. Symptomatic patients should be treated with a combination of corticosteroid and tamoxifen as first-line therapy based on retrospective case series and experience in other fibrosing disorders. Surgical intervention may be required in those with persistent obstruction despite conservative treatment, though complete resection of the mass is often not feasible given intimate involvement with the mesenteric vasculature. A careful use of terminology and communication between the radiologist, pathologist, and clinicians in the care of these patients will be essential to future efforts at understanding this disease.

IS MESENTERIC PANNICULITIS A SIGN FOR AUTOIMMUNE DIABETES IN ADULTS?

OBJECTIVE

Mesenteric panniculitis (MP) and sclerosing mesenteritis is an umbrella term used to describe a rare, chronic, and frequently benign fibrosing inflammatory disease that affects the adipose tissue of the mesentery. The diagnosis is usually based on imaging (computed tomography [CT] or magnetic resonance imaging) findings and is confirmed by biopsy. We report the unusual case of a patient with MP with typical CT findings and diabetes mellitus (DM).

METHODS

A 48-year-old male presented for symptomatic new onset DM. An abdominal CT scan revealed a well-defined mesenteric mass compatible with MP. The combination of insulin degludec and sitagliptin/metformin resulted in a decrease of HbA1c; however, this was followed by a subsequent gradual increase in HbA1c and positive glutamic acid decarboxylase auto-antibodies.

RESULTS

The patient developed auto-immune DM that was confirmed by the presence of auto-antibodies.

CONCLUSION

Panniculitis has been infrequently reported in patients with type 2 DM. This is the first report of a patient with MP correlated with auto-immune DM. The possible pathophysiologic mechanisms are discussed.

Sclerosing mesenteritis: a comprehensive clinical review

Sclerosing mesenteritis is a rare disease entity initially described in 1924 with a prevalence reported to be less than 1%. Sclerosing mesenteritis is a comprehensive term used to describe three almost similar clinical entities including mesenteric panniculitis, retractile mesenteritis, and mesenteric lipodystrophy which only differ by their histology. The etiology of sclerosing mesenteritis is uncertain, but the disease has been associated with trauma, autoimmune disease, surgery, and malignancy. The typical presenting symptom is the abdominal pain, but sclerosing mesenteritis has a broad constellation of presenting symptoms which often makes consideration of the diagnosis unlikely. Treatment for this little-understood disease ranges from surgical intervention for patients presenting with obstructive symptoms to immunosuppressive medical therapy for patients presenting with pain. The purpose of this article is to provide an overview of the literature relevant to the diagnosis, etiology, and management of this condition in hopes of making physicians aware of this unique condition.

Benign Sclerosing and Fibrosing Conditions of the Abdomen and Their Potential Mimics

The process of abnormal reparative or reactive processes in the abdominal cavity, can lead to sclerosis and fibrous deposition. The relatively recent discovery of an IgG4 subgroup of immune mediated sclerosing disease 1,2 has thrown some light on the pathophysiology of these conditions. Firstly, our pictorial review aims to describe imaging findings to enhance the general radiologist's recognition and interpretation of this varied group of benign sclerotic and fibrotic abdominal processes. Secondly, along with the imaging findings, we bring into discussion the potential mimics of these pathologic processes to minimise interpretational errors. Moreover, some of the mimics of these processes are in the spectrum of malignant disease. Most importantly, to ensure a correct diagnosis thorough clinical and histopathological assessment are required to support the imaging findings presented in this review.

Mesenteric Panniculitis Presenting as Fever of Unknown Etiology in a Patient with History of Abdominal Surgery

Mesenteric panniculitis is characterized by nonspecific fibrous inflammation of the small bowel mesentery, appendix, and mesoappendix. Clinical course is usually benign and outcome is favorable. We report a case of mesenteric panniculitis presenting as fever of unknown etiology in a patient with history of abdominal surgery.

An Autopsy Case of Mesenteric Panniculitis with Massive Pleural Effusions

BACKGROUND Mesenteric panniculitis (MP) is an idiopathic chronic inflammatory condition of the mesentery. The main symptoms include abdominal pain, abdominal distention, weight loss, fever, nausea, and vomiting. The patients also present with chylous ascites in 14% of the cases and chylous pleural effusion (CPE) in very rare occasions. Despite the previous view of excellent prognosis of MP, two recent papers reported several fatal cases. However, there are still only a few autopsy case reports that describe the macroscopic and histological details of MP cases. CASE REPORT The patient was an 81-year-old Japanese woman. She complained of edema of her lower legs and face, general fatigue, and dyspnea. She was overweight and had type 2 diabetes (T2D). Computerized tomography (CT) demonstrated massive bilateral pleural effusions, with mild pericardial effusion and mild ascites. There was no pulmonary, cardiac or hepatic condition to explain the effusions. However, MP was suspected based on her CT. She gradually deteriorated into respiratory failure. The autopsy revealed CPEs (left 1,300 mL, right 1,400 mL) and MP in the mesentery of the small intestine. Neither neoplasia nor inflammatory conditions other than MP were detected. CONCLUSIONS In rare occasions, patients with MP present with CPE or chylothorax. We thought that a possible mechanism of the CPEs was a diaphragmatic defect. We suspected that being overweight and T2D had an etiological relationship with MP in our patient's case. Adipose tissue of the mesentery is the main focus of MP. We believed that MP would be the best umbrella term of the many synonyms.

Duplex Doppler Sonographic Assessment of the Superior Mesenteric Artery in Patients With Mesenteric Panniculitis

OBJECTIVES

We aimed to determine how the hemodynamic parameters of the superior mesenteric artery are affected in mesenteric panniculitis.

METHODS

Twenty-one patients with a diagnosis of mesenteric panniculitis on computed tomography were evaluated with duplex Doppler sonography. The control group consisted 20 asymptomatic volunteers. The peak systolic velocity, end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI), blood flow volume, and body mass index were measured in the group of patients with mesenteric panniculitis, and the findings were compared with those of the control group.

RESULTS

The mean blood flow volume and EDV were significantly higher in the patient group: The mean superior mesenteric artery blood flow volume ± SD was 917.86 ± 228.97 mL/min in the patient group versus 389.73 ± 92.72 mL/min in the control group (P < .001). The mean EDV was 31.56 ± 8.44 m/s in the patient group versus 19.27 ± 4.19 m/s in the control group (P < .001). The mean RI and PI were significantly lower in the patient group: The mean RI was 0.81 ± 0.04 in the patient group versus 0.85 ± 0.03 in the control group (P = .001). The mean PI was 2.69 ± 0.68 in the patient group versus 3.81 ± 1.13 in the control group (P = .001). the mean superior mesenteric artery diameter was 7.30 ± 0.67 mm in the patient group versus and 6.46 ± 0.66 mm in the control group (P < .001). The mean BMI was 27.95 ± 3.80 kg/m² in the patient group versus 23.16 ± 3.47 kg/m² in the control group (P < .001).

CONCLUSIONS

In patients with mesenteric panniculitis, the Doppler spectrum of the superior mesenteric artery shows detectable changes, which are characterized by decreased vascular resistance and increased blood flow.

Association between misty mesentery with baseline or new diagnosis of cancer: a matched cohort study

We compared the prevalence of a baseline diagnosis of cancer in patients with and without misty mesentery (MM) and determined its association with the development of a new cancer. This was a retrospective, HIPAA-compliant, IRB-approved case-control study of 148 cases and 4:1 age- and gender-matched controls. Statistical tests included chi-square, t-test, hazard models, and C-statistic. Patients with MM were less likely to have cancer at baseline (RR=0.74, p=0.003), but more likely to develop a new malignancy on follow-up (RR=2.13, p=0.003; survival analysis HR 1.74, p=0.05). MM may confer an increased probability of later developing cancer, particularly genitourinary tumors.

Is there an association between mesenteric panniculitis and lymphoma? A case control analysis

AIM

To determine the prevalence and association of mesenteric panniculitis (MP) in a group of patients with non-Hodgkin's lymphoma (NHL) compared to control group.

MATERIALS AND METHODS

We retrospectively evaluated computed tomography (CT) and combined positron-emission tomography (PET) with CT examinations of a total of 166 patients who were diagnosed with NHL over a period of 5 years (2008-2013). The control group consisted of 332 subjects who were matched for gender and age at the time period the examinations were performed on the study group. A combination of radiological signs and absence of 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG)-uptake was used to establish the diagnosis of MP and distinguish it from the involvement of mesentery by lymphoma.

RESULTS

MP was identified in three patients (prevalence 1.8%) from the study group as compared to seven subjects out of 332 (2.1%) in the control group (p=0.556). During the course of follow-up no changes in the imaging features of MP were seen in either group. Additionally, 27 (16.2%) patients from the study group were found to have changes in the mesentery, which were attributed to the involvement of the mesentery in the primary disease.

CONCLUSION

The prevalence of MP among patients with NHL was found to be 1.8%, which corresponds to the range of its prevalence in the general population. This is contrary to the proposition that MP is associated with NHL.

Sclerosing mesenteritis and mesenteric panniculitis - clinical experience and radiological features

BACKGROUND

Sclerosing mesenteritis (SM) is sometimes used as an umbrella-term for idiopathic inflammatory conditions in the mesentery. Mesenteric panniculitis (MP) is a radiological finding and its relation to clinical SM is not fully understood. The aims of this study were to determine whether any correlation could be found between the radiological findings and the clinical disease course.

METHODS

Patients observed due to idiopathic inflammation of the mesentery were identified. If SM could be verified histologically or MP radiologically, the patients were included in this descriptive retro perspective study.

RESULTS

Typical radiological changes were observed in 27 patients. A majority (23/27) of these patients had mild to moderate symptoms. This group with typical radiology was labelled MP. Four patients were included due to histologically verified disease but had uncharacteristic radiology involving multiple compartments of the abdomen. All four had marked systemic inflammation, fever and fluctuating radiologic findings. Three had severe disease with multiple hospitalisations and complications but responded promptly to corticosteroids. This group was denoted SM.

CONCLUSIONS

We have identified two subgroups of patients; firstly, MP with stable and characteristic radiologic changes and secondly SM with atypical radiology and a more aggressive clinical course. We propose that the term SM should be reserved for this latter condition.

Mesenteric panniculitis: review of consecutive abdominal MDCT examinations with a matched-pair analysis

Background The relationship between mesenteric panniculitis (MP), a benign condition involving adipose mesenteric tissue, and malignancy is still being questioned. Purpose To investigate the prevalence of MP and study its relationship with malignancy. To investigate the 5-year outcome of MP patients for the development of malignancy. Material and Methods Retrospective search for MP reviewing 3054 consecutive multidetector row computed tomography (MDCT) scans. Two radiologists in consensus selected the final MP population. For each MP, two subsequent MDCT scans of patients matched by gender and age. Five-year follow-up data regarding cancer occurrence after index MDCT scans were obtained for the MP and control groups. Comparisons between groups were performed using univariate conditional logistic regression. Results A total of 160 patients had at least three of the five MDCT features defining MP. Sixty-four were excluded owing to disease causing mesenteric infiltration or contiguous neoplastic involvement. The final population included 96 MP and 192 control patients. The prevalence of MP was 3.14%. Most cases of MP were discrete (66.7%), 2.1% were marked. In total, 60.4% and 59.4% of MP and control patients, respectively, had cancer ( P = 0.86). There was no significant association between MP score and presence of cancer ( P = 0.06) nor any relationship between the course of associated cancer and MP evolution. In total, 80/96 MP patients and 50/78 control patients without associated cancer had a 5-year follow-up at least. No significant difference between both groups for new tumor occurrence during follow-up was found ( P = 0.15). Conclusion Our results do not suggest that patients with incidentally found MP should be followed up for early detection of a cancer.

[Mesenteric panniculitis associated with acute pancreatitis: about a case]

Mesenteric panniculitis is a nonspecific inflammation involving the mesentery. Its clinical presentation is variable depending on the stage of the disease. Clinical signs are usually pain but half of the patients remain asymptomatic. Palpable abdominal mass, weight loss, nausea and vomiting. There may be an inflammatory syndrome of variable intensity. Panniculitis is suspected based on scan showing hyperdense mesentery with adhesions to adjacent organs. Histologically there is adipocyte degeneration causing foreign body reaction and appear lymphoplasmacytic inflammatory lesions. We report a new case of mesenteric panniculitis associated with acute pancreatitis.

A systematic investigation of sclerosing mesenteritis through CT and MRI

Sclerosing mesenteritis is primarily diagnosed through histologic and radiologic evaluation; however, only a few works provide a systematic description using MRI. This work presents the case of a 68-year-old male, who was admitted for a routine cholecystectomy. Intraoperativly, a large mass was identified dislocating the abdominal viscera. The microscopic examination revealed vascular congestion of the omentum. The contrast-enhanced CT and MRI scans revealed the presence of a heterogenous, lipomatous mass with lesions visible only in T2W and contrast-enhanced T1W MRI. Based on these findings, the diagnosis of sclerosing mesenteritis was made. According to the available literature, depending on the stage of sclerosing mesenteritis, different radiologic features are encountered; however, it is possible that features from more than one form of the condition coexist in the same lesion. We therefore suggest that a combination of MRI sequences should be acquired for a more accurate staging of the condition.

The mesentery: structure, function, and role in disease

Systematic study of the mesentery is now possible because of clarification of its structure. Although this area of science is in an early phase, important advances have already been made and opportunities uncovered. For example, distinctive anatomical and functional features have been revealed that justify designation of the mesentery as an organ. Accordingly, the mesentery should be subjected to the same investigatory focus that is applied to other organs and systems. In this Review, we summarise the findings of scientific investigations of the mesentery so far and explore its role in human disease. We aim to provide a platform from which to direct future scientific investigation of the human mesentery in health and disease.

Cohort study of mesenteric panniculitis and its relationship to malignancy

Background

Mesenteric panniculitis (MP) is a rare condition that historically has been associated with the presence of malignancy. Paraneoplastic phenomena in general regress with cure and in most cases with treatment of the cancer. This study was undertaken to determine whether MP regressed with cancer treatment and cure.

Methods

This was a retrospective review of a database of all patients with MP confirmed on CT between 2003 and August 2015 at Christchurch Hospital. Patients were categorized as having malignant or non-malignant disease, and follow-up scans were assessed for remission of MP. Patients with malignancy were further categorized as having malignancy cured or not cured.

Results

A total of 308 patients were identified with possible MP; 135 were excluded as radiological appearances were not typical of MP (43 patients) or there was no follow-up CT (92). Of 173 patients (131 men) included, 75 (43·4 per cent) were diagnosed with malignancy. Follow-up imaging showed that 33 patients (19·1 per cent) had remission of MP, whereas 140 (80·9 per cent) had no remission. There was no difference in the rates of MP remission in the malignancy versus no malignancy groups (P = 1·000), or between groups in which malignancy was cured or not cured (P = 0·572). Nor was there any difference in the rates of MP remission in malignancy cured versus no malignancy groups (P = 0·524).

Conclusion

MP does not behave like a paraneoplastic phenomenon. The association with malignancy is most likely an epiphenomenon of the many CT images acquired for staging of cancer.

[Mesenteric panniculitis]

Mesenteric panniculitis is a condition characterized by chronic nonspecific inflammation of the mesentery. There is little and often confusing information about its characteristics and the approach to take once it has been demonstrated by an imaging test. We propose to describe the epidemiological, clinical, laboratory, radiological and pathological features of the patients with mesenteric panniculitis reported in the literature, as well as possible disorders causal or associated with mesenteric panniculitis, in the opinion of the authors of each study. Finally, we will review the different therapeutic options used and the response to them. To that end a literature search was performed from the main medical databases selecting ítems with information on these aspects. This information was collected on a database stored in SPSS software for further analysis and summary.

The Prevalence of Incidentally Detected Idiopathic Misty Mesentery on Multidetector Computed Tomography: Can Obesity Be the Triggering Cause?

PURPOSE

Misty mesentery appearance is commonly reported in daily practice, usually as a secondary finding of various pathological entities, but sometimes it is encountered as an isolated finding that cannot be attributed to any other disease entity. We aimed to assess the prevalence of cases with incidentally detected idiopathic misty mesentery on computed tomography (CT) and to summarize the pathologies leading to this appearance.

METHODS

Medical records and initial and follow-up CT features of patients with misty mesentery appearance between January 2011 and January 2013 were analysed. The study included cases with no known cause of misty mesentery according to associated CT findings, clinical history, or biochemical manifestations, and excluded patients with diseases known to cause misty mesentery, lymph nodes greater than a short-axis diameter of 5 mm, discrete mesenteric masses, or bowel wall thickening.

RESULTS

There were a total of 561 patients in whom misty mesentery appearance was depicted on abdominopelvic CT scans. A total of 80 cases were found to have isolated incidental idiopathic misty mesentery, giving a prevalence of 7%. The common indication for CT examination was abdominal pain. There was a slight female predominance (51.3%). 67.5% of all patients were classified as obese and 17.5% as overweight.

CONCLUSIONS

The results of the present study show that idiopathic incidental misty mesentery appearance has a significant prevalence. Also, the high body mass index of these patients and the growing evidence of obesity-induced inflammatory changes in adipose tissue are suggestive of an association between obesity and misty mesentery appearance on CT.

Mesenteric panniculitis: systematic review of cross-sectional imaging findings and risk of subsequent malignancy

Objectives

Systematic review to determine any association between imaging features of idiopathic mesenteric panniculitis (MP) and subsequent malignancy.

Methods

Two researchers searched primary literature independently for imaging studies of MP. They extracted data focusing on methodology for unbiased patient accrual and capability to determine a link between MP and subsequent malignancy. They noted imaging features of MP. Data were accrued and meta-analysis intended.

Results

Fourteen of 675 articles were eligible; 1,226 patients. Only three (21 %) accrued patients prospectively. Twelve (86 %) studies described CT features. Follow-up varied widely; 1 month to 8 years. Prevalence of MP was influenced by accrual: 0.2 % for keyword search versus 1.7 % for consecutive series. Accrual bias affected nine (64 %) studies. 458 (38 %) of 1,209 patients had malignancy at accrual but varied widely (8–89 %), preventing meta-analysis. Sixty (6.4 %) of 933 patients developed new malignancy subsequently, also varying widely (0–11 %). Of just four studies that determined the proportion of unselected, consecutive patients with MP developing subsequent malignancy, three were retrospective and the fourth excluded patients with lymphadenopathy, likely excluding patients with MP.

Conclusion

Studies were heterogeneous, with biased accrual. No available study can determine an association between MP and subsequent malignancy with certainty.

Key Points

• Our systematic review of mesenteric panniculitis found that imaging studies were biased.

• Spectrum and recruitment bias was largely due to retrospective study designs.

• No study could confirm a certain link between mesenteric panniculitis and subsequent malignancy.

• Excessive methodological heterogeneity precluded meaningful meta-analysis.

• High-quality research linking mesenteric panniculitis imaging features and subsequent malignancy is needed.

Malignancy and mesenteric panniculitis

AIM

Mesenteric panniculitis (MP) is a chronic inflammatory process of the small bowel mesentery that has been reported in conjunction with malignancy. The objectives of the present study were to identify the frequency and type of cancers that may coexist with MP and whether these can be seen on the initial diagnostic computerised tomography (CT).

METHOD

A prospective database was kept of patients diagnosed with MP in the Canterbury region of New Zealand between 1 January 2003 and 31 December 2014. CT scans were independently reviewed. Clinical records were reviewed and family doctors were contacted for additional information.

RESULTS

There were 302 patients with possible MP identified and 259 in whom it was confirmed on review. Seventy-eight patients had a diagnosis of malignancy, with 54 having a current cancer (59 total cancers), 33 a past cancer and nine both. Of the 59 current cancers the most common primary sites were colorectum (19), lymph nodes (17), kidney (six) and prostate (four). Fifty-four were at sites included on an abdominal CT scan. At all sites [except prostate (0/4)] there were high rates of detection on CT with 44/54 cancers visible including 20/23 gastrointestinal tract, 14/17 lymphomas and 9/9 non-prostate urogenital tract malignancies. Six people were subsequently diagnosed with cancer after the index CT.

CONCLUSION

When MP occurs in association with malignancy, the commonest primary sites are large bowel, the lymph nodes and the urogenital tract. In those with MP on imaging, any cancer except prostate can usually be seen on the index CT. Further extensive investigation in asymptomatic patients is therefore likely to be of low yield.

De-misty-fying the mesentery: an algorithmic approach to neoplastic and non-neoplastic mesenteric abnormalities

Mesenteric abnormalities are often incidentally discovered on cross-sectional imaging performed during daily clinical practice. Findings can range from the vague "misty mesentery" to solid masses, and the possible etiologic causes encompass a wide spectrum of underlying pathologies including infectious, inflammatory, and neoplastic processes. Unfortunately, the clinical and imaging findings are often non-specific and may overlap. This article discusses the various diseases that result in mesenteric abnormalities. It provides a framework to non-invasively differentiate these entities, when possible.

Mesenteric panniculitis: still an ambiguous condition

PURPOSE

To study the possible relationship between mesenteric panniculitis (MP) visible on computed tomography (CT) and the presence of an underlying neoplastic disease.

PATIENTS AND METHODS

A retrospective analysis of 158 patients with CT examinations that revealed the presence of MP was performed. CT images were analyzed by two different radiologists using morphological criteria validated in the radiological literature. The presence, frequency and type of neoplastic lesions associated with MP were assessed.

RESULTS

MP was asymptomatic in 96/158 patients (61%). Fat halo sign and pseudocapsule were visible on CT in 89/158 (56%) and 93/158 (59%) patients, respectively. Underlying neoplastic disease was present in 88/158 patients (56%). The neoplastic diseases most often associated with MP were lymphoma (28%), melanoma (18%), colorectal cancer (15%) and prostate cancer (13%).

CONCLUSION

MP has typical CT appearance and is associated with underlying neoplastic disease in 56% of patients. Such levels of association might suggest that MP may be considered as a paraneoplastic condition. Hence, incidental depiction of MP on CT in a patient without known neoplastic disease should incite radiologists to further scrutinize CT examination for presence of synchronous neoplastic lesions.

Mesenteric panniculitis: prevalence, clinicoradiological presentation and 5-year follow-up

OBJECTIVE

To determine prevalence, clinicoradiological characteristics and outcome of patients with mesenteric panniculitis (MP) in a large hospital-based population.

METHODS

Consecutive abdominal CT examinations of 3820 patients were evaluated for MP. Clinical characteristics, therapy and outcome of patients with MP were evaluated during a 5-year follow-up period. A matched pair analysis was performed to further investigate the relation between MP and malignancy.

RESULTS

94 (2.5%) patients with MP were identified (mean age, 66.6 ± 11.2 years, 70.2% male). MP coexisted with malignancy (especially prostatic carcinoma) in 48.9% of patients, and this was slightly but significantly higher than in age- and sex-matched control patients (n = 188, 46.3%). In 48 patients, MP was presumed to be idiopathic. The most frequent presenting symptom was pain (54.3%). Laboratory findings revealed increased acute-phase reactants in half of the patients with MP. CT findings included increased density of mesenterial fat (mean, -56.8 ± 10.8 HU), fat ring sign, tumoural pseudocapsule and small soft-tissue nodules. Patients with MP (14.6%) developed significantly more malignancies during a 5-year follow-up than did the control group (6.9%). One patient was treated with prednisone without satisfactory response.

CONCLUSION

The prevalence of MP in this study was 2.5%. In most patients, radiologic features included increased mesenteric fat density, fat ring sign and small soft-tissue nodules. MP was associated with a significant higher prevalence of coexisting malignancies and a higher prevalence of future cancer development.

ADVANCES IN KNOWLEDGE

A more accurate prevalence of MP on CT is demonstrated. An underlying malignancy may play a role.