Sclerosing mesenteritis, mesenteric panniculitis and mesenteric lipodystrophy: a single entity?

Mesenteric panniculitis in oncologic patients: PET-CT findings

The aim of this study is to assess the role of PET/CT in differentiating between mesenteric panniculitis (MP) and co-existing MP and mesenteric tumoural involvement. A total of 33 PET/CT examinations, of 19 oncologic patients (16 men and three women with ages ranging from 48 years to 83 years) with findings of MP on the CT part of the study were retrospectively reviewed. The FDG uptake in mesenteric nodules was recorded. The final diagnosis of malignant mesenteric involvement was based on clinical and imaging follow-up. Based on the FDG uptake in mesenteric nodules, patients were categorized as group A: increased mesenteric uptake (n=8) and group B: no mesenteric uptake (n=11). In seven of the eight patients in group A, a co-existing MP and mesenteric tumour involvement was found: one patient had a recurrent cervical carcinoma and the other six patients had lymphoma. In four of these six patients, the positive PET findings disappeared on follow-up PET/CT with complete remission while the CT findings of the MP remained unchanged. In the other two, the PET findings progressed along with clinical deterioration. In the last patient of group A, with rectal carcinoma without evidence of recurrence, the mesenteric FDG uptake was a false positive uptake. In all 11 patients with CT findings of MP and negative PET, no malignant involvement of the mesentery was diagnosed. To conclude, a negative PET has a high diagnostic accuracy in excluding tumoural mesenteric involvement while increased uptake suggests the co-existing of mesenteric deposits, particularly in patients with lymphoma.

Mechanisms of disease: adipocytokines and visceral adipose tissue--emerging role in intestinal and mesenteric diseases

Adipose tissue has long been regarded as a passive type of connective tissue that stores energy as triglycerides and releases energy as free fatty acids, however, this point of view has now changed. The wide variety of products expressed and secreted by adipose tissue, such as adiponectin, leptin, and resistin, mean that the total adipose tissue mass can be defined as a real endocrine organ. The anatomic, metabolic and biochemical characteristics of visceral adipose tissue make it interesting in the context of intestinal and mesenteric diseases. These characteristics include increased lipolysis, venous drainage via the portal vein and local glucocorticoid excess owing to the specific expression of 11-beta-hydroxysteroid-dehydrogenase type 1. In this review, the role of the visceral adipose tissue and its secretory products in intestinal and mesenteric diseases is systematically reviewed, with special focus on 'creeping fat' in Crohn's disease and mesenteric panniculitis.

[Mesenteric panniculitis]

Mesenteric panniculitis also named retractile mesenterite is a rare tumor-like lesion that thickens and shortens the mesentery. It is characterized by the association of inflammation, necrosis or fibrosis involving the adipose tissue of the bowel mesentery. The pathophysiology of this disease remains unclear despite associations with inflammatory diseases or malignancies, especially lymphomas that have been described. When symptomatic, patients may present with abdominal pain, palpable abdominal mass or intestinal obstruction. The disease remains asymptomatic in 30 to 50% of cases. Abdominal CT plays an important role in suggesting the diagnosis and can be useful in distinguishing the several conditions that can mimic mesenteric panniculitis. Nevertheless, pathologic examination of surgical excisional biopsies or sometimes percutaneous biopsies remains necessary to confirm the diagnosis and exclude an underlying infection or malignancy. Medical treatment may consist of therapy with anti inflammatory or immunosuppressive agents and can be proposed in highly symptomatic diseases. Surgical treatment should be exclusively attempted when intestinal obstruction or ischemia occur. Most of the time, it consists in intestinal derivation or segmental resection because complete excision of the lesions is often not possible. Mesenteric panniculitis usually has an uneventful clinical course and resolves spontaneously in a variable delay.

Sclerosing mesenteritis

Sclerosing mesenteritis is a rare benign process involving mesenteric fat that has non-specific histology and imaging characteristics, which are critical to the diagnosis. It has two different pathological variants: mesenteric panniculitis (acute or subacute) and retractile mesenteritis (chronic). This case study illustrates the radiological findings of sclerosing mesenteritis, describes certain signs that suggest the diagnosis and reviews recent published literature.

Mesenteric panniculitis versus pancreatitis: a computed tomography diagnostic dilemma

A case of mesenteric panniculitis is described in a patient with CT features mimicking pancreatitis. Emphasis is on the important CT features for accurate diagnosis.

Reactive nodular fibrous pseudotumors of the gastrointestinal tract: report of 8 cases

Eight cases of reactive nodular fibrous pseudotumor of the gastrointestinal tract are presented. The patients included 6 males and 2 females between the ages of 1 and 68 years (mean age 41.5 years). Three tumors involved the small intestine, and 5 of the investigated lesions were located in the large bowel. Of these, 2 originated in the sigmoid colon, 1 in the cecum, 1 in the appendix, and 1 in the large bowel not otherwise specified. The tumors' size varied from 3 to 10 cm in the greatest diameter (mean 6.2 cm). Histologically they were composed of stellate or spindle shaped cells resembling fibroblasts arranged haphazardly or in intersecting fascicles, embedded in a collagen-rich stroma, with sparse intralesional mononuclear cells frequently arranged in lymphoid aggregates. Immunohistochemically, the lesions were positive for vimentin (7/7), smooth muscle actin (8/8), muscle-specific actin (5/7), cytokeratins AE1/AE3 (6/7), and CAM 5.2 (1/7), and antigen CD68 (1/7). No case (0/8) reacted positively with antibody to CD117 (c-kit). Genetically no substitutions, deletions, or insertions occurred in exon 11 in all analyzed samples. Likewise, no deletions or insertions in part of exon 9 were observed. Ultrastructurally the tumor cells revealed features typical of myofibroblasts. According to the morphologic, immunohistochemical, and ultrastructural features mentioned above, especially to the positivity of low-molecular-weight cytokeratins, we propose this lesion to be related to a proliferation of multipotential subserosal cells rather than ordinary myofibroblasts or fibroblasts.

Sclerosing mesenteritis in small bowel transplantation: possible manifestation of acute vascular rejection

BACKGROUND

Acute rejection of human small bowel allografts is characterized by clinical symptoms combined with characteristic morphologic alterations. The typical geographic distribution of acute rejection in the bowel is involvement of the intestinal parenchyma, which can be transmural, particularly when the rejection is more severe. However, little is known concerning the potential for donor-derived soft tissue adjacent to the bowel to become involved by the host alloimmune response.

METHODS

We describe a male patient who, several weeks after combined small bowel and liver transplantation, demonstrated sclerosing mesenteritis with vasculitis and acute rejection of the bowel.

RESULTS

The vascular lesions in the mesentery demonstrated increased IgG deposition and the patient developed an alloantibody to the donor.

CONCLUSIONS

The changes described herein may represent a novel presentation of acute vascular rejection.

Mesenteric panniculitis: US and CT features

Mesenteric panniculitis is an aseptic inflammation of mesenteric fat. Before the age of ultrasonography (US) and computed tomography (CT), mesenteric panniculitis was rarely diagnosed, but today the disorder is more commonly encountered, often as an incidental imaging finding. Its exact cause remains unknown. This review illustrates the characteristic US and CT features of mesenteric panniculitis and discusses its differential diagnosis.

A fatal case of sclerosing mesenteritis

A 22-year-old patient was admitted because of abdominal pain and vomiting. Computed tomography diagnosed small intestinal malignancy. Ileal resection was performed, and the histological findings were consistent with sclerosing mesenteritis. The patient was treated with enteral nutrition, corticosteroids, azathioprine and methotrexate, but died 2 years later.

Ossification hétérotopique du mésentère : une cause rare d’occlusion post-opératoire

Intraabdominal heterotopic ossification is a very rare lesion, especially in the mesentery. In all reported series, there was a history of traumatic injury of the abdomen. We report two cases of heterotopic mesenteric ossification occurring after laparotomy in adults.

CT findings in sclerosing mesenteritis (panniculitis): spectrum of disease

Sclerosing mesenteritis is a complex inflammatory disorder of the mesentery. Although sclerosing mesenteritis is often associated with other idiopathic inflammatory disorders such as retroperitoneal fibrosis, sclerosing cholangitis, Riedel thyroiditis, and orbital pseudotumor, its exact cause is unknown. The computed tomographic (CT) appearance of sclerosing mesenteritis will vary depending on the predominant tissue component (fat, inflammation, or fibrosis). CT plays an important role in suggesting the diagnosis in the proper clinical setting and can be useful in distinguishing sclerosing mesenteritis from other mesenteric diseases with similar CT features such as carcinomatosis, carcinoid tumor, lymphoma, desmoid tumor, and mesenteric edema. Nevertheless, surgical biopsy and pathologic analysis are usually necessary to make the diagnosis. Treatment may consist of therapy with steroids, colchicine, immunosuppressive agents, or orally administered progesterone. Surgical resection is sometimes attempted for definitive therapy, although the surgical approach is often limited by vascular involvement. CT with three-dimensional volume rendering is optimal for accurate, noninvasive follow-up of sclerosing mesenteritis and of any potential complications.

Primary non-Hodgkin lymphoma of the jejunum associated with mesenteric lipodystrophy: A case report

Mesenteric lipodystrophy is a rare condition characterized by a nonspecific inflammatory process that involves the root of the mesentery in a lipoma-like lesion. We reported a case of sclerosing mesenteritis presenting as recurrent abdominal pain, profound weight loss, dilated cardiomyopathy, malabsorption and a mass on computed tomography scan of the abdomen in a 42 years old man with previous history of lymphoma. Because of the wider differential diagnosis in such cases, the patient underwent an extensive workup culminating in a laparoscopy with biopsy. This case illustrated that mesenteric lipodystrophy should be included in the differential diagnosis of retroperitoneal and mesenteric tumor.

F-18 FDG PET demonstration of sclerosing mesenteritis

Sclerosing mesenteritis is a rare, combined inflammatory and fibrotic process of unknown etiology. Detailed cross-sectional imaging of this entity has been reported with computed tomography. The author presents an additional case of sclerosing mesenteritis demonstrated on fluorine-18 fluorodeoxyglucose positron emission tomography with multidetector computed tomographic correlation.

Reactive nodular fibrous pseudotumor of the gastrointestinal tract and mesentery: a clinicopathologic study of five cases

Although the majority of mesenchymal lesions of the gastrointestinal tract are neoplastic in nature, nonneoplastic reactive processes may involve the gastrointestinal tract and mesentery, causing diagnostic confusion with more aggressive neoplasms, such as fibromatosis or gastrointestinal stromal tumors. In this study, we report a series of fibroinflammatory lesions of the gastrointestinal tract that we think represent a relatively cohesive group of tumors and describe the clinical and pathologic features of this entity, which we have termed "reactive nodular fibrous pseudotumor." The tumors affected five patients (four male and one female patient) who ranged in age from 48 to 71 years (mean 56 years). Two patients presented with acute abdominal pain without a significant past medical history, two had incidental lesions discovered during evaluation for other medical conditions, and one was found to have an abdominal mass. Three patients had a history of abdominal surgery. The tumors were multiple in three patients and solitary in two patients. In four cases, at least one of the tumors involved the small intestine or colon, and the lesion was confined to the peripancreatic soft tissue in one case. The tumors were firm, tan-white, ranged in size from 4.3 to 6.5 cm in greatest dimension, and were grossly well circumscribed. All of the lesions were of low to moderate cellularity and composed of stellate or spindled fibroblasts arranged haphazardly or in intersecting fascicles. Three cases had microscopically infiltrative borders. The stroma was rich in collagen, which was wire-like, keloidal, or hyalinized. Intralesional mononuclear cells were sparse but were more numerous peripherally and frequently arranged in lymphoid aggregates. Immunohistochemical stains demonstrated that all of the tumors stained for vimentin, 80% stained for CD117 or muscle specific actin, 60% stained for smooth muscle actin or desmin, and none of the tumors stained for CD34, S-100 protein, or anaplastic lymphoma kinase-1. Follow-up information was available in all cases: four patients had no residual disease following surgical resection (mean follow-up 16.3 months) and one patient who had an incomplete surgical resection had stable disease at 26 months. In summary, we report a series of distinct intraabdominal fibroinflammatory pseudotumors that we have collectively termed "reactive nodular fibrous pseudotumors." These lesions are uncommon and may infiltrate the bowel wall, thereby mimicking primary bowel neoplasms or intraabdominal fibromatosis. Recognition of these nonneoplastic lesions is important, as they pursue a benign clinical course, but may be confused with other mesenchymal neoplasms that require more aggressive treatment.

A pilot study of thalidomide for patients with symptomatic mesenteric panniculitis

BACKGROUND

Mesenteric panniculitis is a rare condition with no standard therapy.

AIM

To assess the safety and efficacy of thalidomide for the treatment of patients with symptomatic mesenteric panniculitis using a newly established clinical disease activity index (Mesenteric Panniculitis Subjective Assessment Score).

METHODS

In an open-label pilot study, five patients with symptomatic mesenteric panniculitis received oral thalidomide, 200 mg nightly, for 12 weeks. The primary end-point was a reduction in the Mesenteric Panniculitis Subjective Assessment Score by > or = 20% at 12 weeks or complete remission (absence of symptoms).

RESULTS

Four (80%) of the five patients responded. The median Mesenteric Panniculitis Subjective Assessment Score at baseline was 39 and at week 12 was 25 (average decrease of 44%). One patient achieved complete remission by week 4, which was sustained. At 12 weeks, three (75%) patients experienced a global response, five (100%) patients had a > or = 20% (range, 29-98%) decrease in erythrocyte sedimentation rate and three (75%) patients had a > or = 20% (range, 61-93%) decrease in C-reactive protein. Abdomino-pelvic computed tomography scans were unchanged in all five patients. There were no serious adverse events.

CONCLUSIONS

Thalidomide is safe, well tolerated and efficacious in the treatment of some patients with symptomatic mesenteric panniculitis. Further study is indicated.

Beta-catenin immunohistochemistry separates mesenteric fibromatosis from gastrointestinal stromal tumor and sclerosing mesenteritis

Although separating gastrointestinal stromal tumor (GIST) from mesenteric fibromatosis and sclerosing mesenteritis is clinically important, this distinction sometimes poses problems for practicing pathologists. In the STI571 (Gleevec, Imatinib) era, the problem may be further compounded when protocol-driven staining for CD117 (c-kit) is performed on spindle cell proliferations presenting in the bowel wall and mesentery using an antibody known to react with the majority of mesenteric fibromatoses when other antibodies are more specific. Because most mesenteric fibromatoses have mutations in the pathway and hence have abnormal nuclear accumulation of beta-catenin protein, we studied beta-catenin expression among a panel of other immunohistochemical stains to distinguish mesenteric fibromatosis, GIST, and sclerosing mesenteritis. Examples of gastrointestinal stromal tumors (GIST, 11), sclerosing mesenteritis (5), and mesenteric fibromatosis (10) were retrieved from the archives of our institutions. Cases were studied with an immunohistochemical panel consisting of CD117, beta-catenin, CD34, smooth muscle actin, desmin, keratin, and S-100 protein. Cases were scored as "negative," "focally positive," or "diffusely positive." In evaluating beta-catenin, nuclear accumulation was required. GIST all had CD117 (11 of 11, diffuse) and CD34 (11 of 11, diffuse) with variable actin (5 of 11, focal) and negative desmin, keratin, S-100 protein. All GIST lacked beta-catenin (0 of 11). Mesenteric fibromatosis had CD117 (6 of 10, 3 focal, 3 diffuse), typically expressed more weakly than in GIST, actin (5 of 9, focal), and desmin (3 of 8, focal) in keeping with myofibroblastic differentiation but lacked CD34, S-100, and keratin. CD117 staining was not eliminated by use of a non-avidin-biotin technique. Nuclear beta-catenin was detected in 9 of 10 fibromatoses, including one case associated with familial adenomatous polyposis. Two of five sclerosing mesenteritis cases focally expressed CD117. None of the sclerosing mesenteritis cases had nuclear beta-catenin. Sclerosing mesenteritis cases were otherwise fibroblastic and myofibroblastic with focal actin in 5 of 5 and negative desmin, keratin, and S-100 protein but one had CD34 (1 of 5, focal). With increasing protocol-driven interest in evaluating bowel wall and mesenteric spindle cell lesions using CD117 (c-kit) antibodies, it is important for practicing pathologists to be aware that lesions other than GISTs are likely to express this antigen using certain antibodies. beta-Catenin staining identifies lesions that are, instead, mesenteric fibromatoses.

Mesenteric panniculitis associated with abdominal tuberculous lymphadenitis: a case report and review of the literature

Mesenteric panniculitis is a rare disease characterized by chronic non-specific inflammation of the mesenteric adipose tissue. The specific aetiology of the disease is previously unknown. A case diagnosed as mesenteric panniculitis is presented. The cause was biopsy-proved abdominal tuberculous lymphadenitis. To our knowledge, mesenteric panniculitis associated with tuberculosis infection has not been reported previously in the literature. Thus, we would like to present the first case and describe CT features of the disease.

Concomitant sclerosing mesenteritis and bile duct fibrosis simulating Klatskin's tumor

Sclerosing mesenteritis is an uncommon benign condition that should be included in the differential diagnosis of abdominal masses. We present the first reported case of this condition in association with idiopathic bile duct fibrosis simulating Klatskin's tumor. A review of the literature regarding both clinical entities is presented.

Calcifying fibrous pseudotumor of mesentery presenting with acute peritonitis: case report with immunohistochemical study and review of literature

Calcifying fibrous pseudotumor (CFP) is a benign soft tissue lesion composed of thick collagen bundles, scattered fibroblasts, and psammomatous and dystrophic calcifications, located most commonly in the extremities and trunk of children and young adults. The present case in a 36-year-old woman is to the best of our knowledge the first report of a large CFP confined to the mesentery, which, because of torsion, led to acute peritonitis and emergency laparotomy. The typical histologic features were accompanied by a prominent myofibroblastic proliferation along with inflammatory response at the periphery of the lesion. The spindle cells of the lesion were positive for vimentin and focally for CD34 and smooth-muscle actin. Review of the literature and discussion of differential diagnosis in this report focuses on abdominal CFP and other intraabdominal soft tissue lesions, some of which may be precursors of CFP. Int J Surg Pathol 9(3):249-253, 2001

Aggressive multiple myeloma presenting as mesenteric panniculitis

Mesenteric panniculitis is a rare disease of the bowel mesentery, characterized by tumor-like infiltration by chronic inflammatory cells, fat necrosis, and fibrosis. Reported cases cited clinical presentation ranging from abdominal pain to fever of unknown origin, the majority of which were idiopathic and associated with a benign prognosis. We report the case of a 43-yr-old male who presented with malaise, weight loss, microcytic anemia, and a high erythrocyte sedimentation rate. Radiographic and histological investigations revealed typical features of mesenteric panniculitis. Initial treatment with high-dose oral prednisolone led to rapid and complete resolution of symptomatology, radiographic, and laboratory anomalies. Within 6 months, the patient presented again with anemia, renal failure, and hypercalcemia. A diagnosis of IgA kappa chain myeloma was made. Despite chemotherapy and restoration of normocalcemia, he died from refractory pulmonary edema. This is the first report of a hematological malignancy initially presenting with features of mesenteric panniculitis culminating in an aggressive course and a fatal outcome.

Peritoneal sclerosis: one or two nosological entities?

The frequency, pathology, animal models, pathogenesis, clinical manifestations, diagnostic criteria, therapy and prevention of peritoneal sclerosis are reviewed. Many of these aspects have a bimodal configuration which suggests that peritoneal sclerosis, usually considered a single pathology in peritoneal dialysis, is actually two distinct nosological entities: simple sclerosis and sclerosing peritonitis. The former is very frequent, with minor anatomical alterations and low clinical impact; it is reproducible in animals by means of peritoneal dialysis, and is clearly due to the poor biocompatibility of peritoneal dialysis solutions. The latter is rare, with radical anatomical alterations and high mortality requiring valid methods of diagnosis, therapy and prevention; it can only be reproduced in animal models by means other than peritoneal dialysis and seems to be due to factors both related and unrelated to peritoneal dialysis.

Inflammatory pseudotumor causing small bowel obstruction and mimicking lymphoma in a patient with AIDS: clinical improvement after initiation of thalidomide treatment

A patient with AIDS was diagnosed with inflammatory pseudotumor with small bowel involvement. After receiving thalidomide treatment, serum tumor necrosis factor (TNF) and soluble TNF receptor II levels normalized, his constitutional and gastrointestinal symptoms diminished, and the mass lesion shrunk.

CT evaluation of mesenteric panniculitis: prevalence and associated diseases

OBJECTIVE

This study was undertaken to assess the prevalence of mesenteric panniculitis on CT and to describe its appearance and associated diseases.

SUBJECTS AND METHODS

A total of 7620 consecutive abdominal CT examinations were prospectively evaluated for features common to mesenteric panniculitis such as a well-delineated inhomogeneous hyperattenuated fatty mass at the mesenteric root, envelopment of mesenteric vessels, and no evidence of invasion of the adjacent small-bowel loops that may be displaced.

RESULTS

CT findings of mesenteric panniculitis were seen in 49 patients (0.6%). We found a female predominance. Mesenteric panniculitis coexisted with malignancy in 34 patients and with benign disorders in 11 patients. In the remaining four patients, mesenteric panniculitis, verified on histology, was considered to be responsible for the patients' clinical manifestations; no other abnormality was identified. Soft-tissue nodules (n = 39) and a fatty halo surrounding vessels and nodules (n = 42) were observed in most patients. Follow-up abdominal CT examinations in 29 of the 49 patients showed changes in only one patient.

CONCLUSION

CT findings of mesenteric panniculitis may be seen in patients undergoing abdominal CT for various symptoms.

Heterotopic mesenteric ossification ('intraabdominal myositis ossificans'): report of five cases

Intraabdominal heterotopic ossification is a very uncommon disorder. We report five new cases, review the previous literature, and discuss the clinical and pathologic features of these lesions. The clinical features of the current cases and of those previously reported are remarkably similar. All patients were middle-aged to elderly men (range, 43-80 years; mean, 61 years) who had small bowel obstruction associated with heterotopic bone formation in the small bowel mesentery, often after one or more abdominal operations. In one case, an initial diagnosis of extraosseous osteosarcoma was considered. This unusual reactive process shares many of the clinical and pathologic features of myositis ossificans, as classically described in somatic soft tissues. We propose to designate this condition heterotopic mesenteric ossification.

Successful treatment of retractile mesenteritis with oral progesterone

Retractile mesenteritis is a rare inflammatory mesenteric disorder that involves the intestine secondarily. The natural history of this process is diverse, but most patients require some empiric therapeutic measures. Up to now, pharmacological therapy has included corticosteroids, colchicine, and immunosuppressive drugs. Although these drugs are successful in most patients, some have been refractory to these therapies and, in others, the beneficial effects were counterbalanced by adverse reactions. Many patients require surgery, but most have poor results. This report describes a 42-year-old man with histologically proven retractile mesenteritis refractory to surgical intervention who had a good response to oral progesterone (10 mg/day for 6 months) with complete disappearance of tumor mass and clinical symptoms. No adverse effects were detected. Current knowledge about the mechanism by which progesterone affects fibrogenesis is scanty. It seems likely that progesterone down-regulates proliferation and metabolism of fibroblasts and fibrogenesis.