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

Sclerosing mesenteritis involving the pancreas: a mimicker of pancreatic cancer

Sclerosing mesenteritis (SM), also known as mesenteric lipodystrophy, rarely involves the parenchyma of the pancreas. When SM does involve the pancreas, it can mimic pancreatic carcinoma both clinically and radiographically with pain, obstructive jaundice, a mass lesion, and even the appearance of vascular invasion. We report 6 patients with SM involving the pancreas (mean age 43.2 y, 5 female), and review their clinical presentation, radiographic findings, pathology, and outcome. Five of these 6 patients were originally thought to have a primary pancreatic neoplasm. Initial presenting clinical information was available for each patient: all 6 reported abdominal or epigastric pain, 3 reported weight loss, and 2 reported one or more of the following: back pain, fever, abdominal bloating/distention, nausea with/without vomiting, and anorexia. The lesions formed masses with an infiltrative pattern and all had 3 key histologic features: fibrosis, chronic inflammation, and fat necrosis-without a known etiology. The inflammatory infiltrate was composed of a mixture of lymphocytes, plasma cells, and scattered eosinophils. Of the 5 patients with post-treatment clinical information available, 4 had at least a partial response to treatment with steroids, tamoxifen, azathioprine, resection, or a combination of these, and 1 did not respond. A dramatic response to immunosuppressive therapy is illustrated by the case of a 46-year-old woman who presented with the presumptive diagnosis of an unresectable pancreatic cancer. Distinguishing SM from pancreatic carcinoma is crucial to appropriate management, as patients with SM may benefit from immunosuppressive therapy.

Paniculite mesentérica pseudotumoral: aspectos tomográficos de um caso

A paniculite mesentérica representa um processo inflamatório do mesentério de ocorrência rara e etiologia desconhecida, que apenas em alguns poucos casos pode se manifestar sob a forma de pseudotumores abdominais. Descreve-se, enfatizando os aspectos tomográficos, um raro caso de paniculite mesentérica que se apresentou inicialmente como um pseudotumor que envolvia a região peripancreática.

A case of sclerosing mesenteritis with rheumatoid arthritis

Sclerosing mesenteritis (SM) is an uncommon disorder characterized by chronic nonspecific inflammation involving the adipose tissue of the mesentery. The etiology remains unclear. It has been reported in association with and as an initial presentation in some autoimmune diseases. Its clinical presentation and laboratory findings are typically nonspecific and definitive diagnosis usually requires biopsy or surgical excision. We report a patient with a history of rheumatoid arthritis who was found to have an intra-abdominal mass suspicious for malignancy. A biopsy revealed the diagnosis of SM.

Idiopathic sclerosing mesenteritis in paediatrics: Report of a successfully treated case and a review of literature

A 6 year old female with symptoms of small bowel obstruction underwent an exploratory laparotomy which revealed widespread evidence of inflammatory fibrotic adhesions involving the jejunal mesentery. In view of persistent growth failure, chronic anaemia, elevated acute phase reactants and imaging evidence of a diffuse progressive inflammatory process, the child was treated with corticosteroids and methotrexate with complete response. The literature on juvenile idiopathic sclerosing mesenteritis has been reviewed.

Idiopathic Isolated Omental Panniculitis Confirmed by Percutaneous CT-Guided Biopsy

The preoperative diagnosis of intraabdominal panniculitis is difficult due to its rarity. However, the increased use of abdominal computed tomography (CT) for a variety of indications has increased the diagnosis of intraabdominal panniculitis, including omental panniculitis. The characteristic CT features of intraabdominal panniculitis are increased attenuation of the adipose tissue, the fat-ring sign, a tumoral pseudocapsule, soft-tissue nodules, and a left-sided orientation of mass maximum transverse diameter. Recognition of these features is valuable in the diagnosis of panniculitis, and hence percutaneous CT-guided biopsy to determine their presence may prevent unwarranted surgery. We report the case of a 61-year-old man found to have an idiopathic isolated omental panniculitis that was diagnosed by abdominal CT and percutaneous CT-guided biopsy.

Relationship between abdominal trauma or surgery and mesenteric panniculitis

Mesenteric panniculitis is a rare disease characterized by chronic non-specific inflammation of mesenteric fat tissue. Several etiologic and/or associated factors have been reported in the literature so far. Although trauma or surgery is one of the potential etiologic factors for mesenteric panniculitis, to the best of our knowledge, no strong correlation has been shown in the literature until now.

An Interesting Case of Recurrent Small Bowel Obstruction

Sclerosing mesenteritis is associated with a spectrum of diseases which include mesenteric lipodystrophy and mesenteric panniculitis. This inflammatory and fibrosing disorder can affect the small and large bowel wall and mesenteric vessels by exerting a mass effect. The following case highlights the difficulties with diagnosing and managing this unusual disease. A 64-year-old man presented with acute central abdominal pain, radiating to his back, and profuse vomiting. He was diagnosed clinically with small bowel obstruction. He had had an episode of small bowel obstruction 6 years earlier. At this time, he underwent an exploratory laparotomy, and a mass was identified in the small bowel mesentery. The features were thought to be in keeping with sclerosing mesenteritis. He had a dramatically favourable response to the initiation of prednisolone. He continued to be well and asymptomatic for a further 5 years on long-term maintenance low-dose steroids and 6-mercaptopurine. He re-presented in 2009 (six years after initial presentation) with very severe acute abdominal pain and vomiting. He had no recent change in weight or appetite, and had not had time off work. He underwent a second laparotomy and the tissue diagnosis was of metastatic carcinoid tumour involving the small bowel mesentery. This is the first case to our knowledge where sclerosing mesenteritis has been confirmed histologically on biopsy and then subsequently diagnosed with histologically proven carcinoid tumour. For this particular reason it must be always remembered that sclerosing mesenteritis is a 'pathological' and not a radiological diagnosis and that a large proportion of cases are associated with neoplasia.

Mesenteric panniculitis: various presentations and treatment regimens

Mesenteric panniculitis is a rare, benign and chronic fibrosing inflammatory disease that affects the adipose tissue of the mesentery of the small intestine and colon. The specific etiology of the disease is unknown. The diagnosis is suggested by computed tomography and is usually confirmed by surgical biopsies. Treatment is empirical and based on a few selected drugs. Surgical resection is sometimes attempted for definitive therapy, although the surgical approach is often limited. We report two cases of mesenteric panniculitis with two different presentations and subsequently varying treatment regimens. Adequate response was obtained in both patients. We present details of these cases as well as a literature review to compare various presentations, etiologies and potential treatment modalities.

Extensive sclerosing mesenteritis of the rectosigmoid colon associated with erosive colitis

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

[Diseases of the peritoneum and mesenterium]

Peritoneal diseases can be seen in the different imaging modalities either as fluid collections or solid tumors along the ligaments, mesenteries, and spaces of the peritoneal cavity. The broad spectrum of different abnormalities includes inflammatory, infectious, traumatic, and neoplastic diseases. In this article, a large variety of peritoneal abnormalities such as ascites, peritonitis, intraperitoneal hemorrhage, and both primary and secondary peritoneal tumors are discussed. The different imaging modalities, characteristic radiological features, and typical pathways of anatomic spread are explained.

An unusual presentation of sclerosing mesenteritis as pneumoperitoneum: Case report with a review of the literature

Sclerosing mesenteritis is a rare condition that involves the small or large bowel mesentery. An unusual presentation of this condition, which led to difficult preoperative assessment and diagnosis, is described. This report is followed by a comprehensive review of the literature.

Detection of MDM2 gene amplification or protein expression distinguishes sclerosing mesenteritis and retroperitoneal fibrosis from inflammatory well-differentiated liposarcoma

Inflammatory liposarcoma is a variant of well-differentiated liposarcoma/atypical lipomatous tumor that consists of a mixture of lymphocytes, histiocytes, scattered atypical stromal cells, mature adipocytes, and rarely lipoblasts. When the inflammatory infiltrate predominates, the morphological features overlap with various fibroinflammatory disorders including sclerosing mesenteritis and retroperitoneal fibrosis, making the diagnosis difficult. Well-differentiated liposarcoma/atypical lipomatous tumor and dedifferentiated liposarcoma have characteristic molecular markers in the form of giant marker and ring chromosomes consisting of amplicons of 12q13-15, which includes MDM2. MDM2 immunohistochemistry (IHC) (Zymed; clone IF2) and dual color fluorescence in situ hybridization utilizing MDM2 (12q15) and chromosome 12 centromeric probes were performed on formalin-fixed and paraffin-embedded specimens from inflammatory well-differentiated liposarcoma (17 cases), sclerosing mesenteritis (14 cases), and idiopathic retroperitoneal fibrosis (10 cases). MDM2 expression as detected by IHC is a very sensitive tool in recognizing inflammatory well-differentiated liposarcoma (17 of 17); however, 21% (3 of 14) and 10% (1 of 10) of sclerosing mesenteritis and retroperitoneal fibrosis, respectively, displayed weak MDM2 immunoexpression. The MDM2 fluorescence in situ hybridization assay was very specific for inflammatory well-differentiated liposarcoma as 15 of 17 (88%) cases showed MDM2 amplification, whereas none of the cases of sclerosing mesenteritis or idiopathic retroperitoneal fibrosis showed amplification. Five cases of retroperitoneal fibrosis were noncontributory secondary to autofluorescence, potentially limiting the usefulness of the assay in certain situations such as inappropriate fixation. Increased MDM2 expression and/or MDM2 amplification can be employed to aid discrimination of inflammatory well-differentiated liposarcoma from fibroinflammatory mimics. MDM2 fluorescence in situ hybridization is a very specific method (100%), but less sensitive (88%), whereas MDM2 expression by IHC is very sensitive (100%), but less specific (83%). Therefore, a positive screen of difficult cases with MDM2 IHC would require confirmation by the fluorescence in situ hybridization. However, lack of MDM2 immunoexpression would rule out the possibility of inflammatory well-differentiated liposarcoma.

Sclerosing mesenteritis affecting the small and the large intestine in a male patient with non-Hodgkin lymphoma: a case presentation and review of the literature

Introduction

Sclerosing mesenteritis is a rare disease resembling a mesenteric tumour. We present here a case of sclerosing mesenteritis that affected both the large and the small intestine of the patient. Therapeutic and diagnostic issues are discussed.

Case presentation

A 62-year-old man with a history of non-Hodgkin lymphoma presented with fatigue, a palpable tender abdominal mass and clinical signs of progressing intestinal obstruction. The preoperative evaluation failed to prove recurrence of the lymphoma or any other definite diagnosis. A laparotomy was performed through a midline incision. The mesentery resembled a tumour-like thickened and fibrotic mass. Abundant, rigid intestinal loop adhesions were observed. Diffuse fibrotic infiltration of the ileum and of the sigmoid colon, which obviously affected the intestinal vascular supply, were identified. A right colectomy and partial sigmoidectomy were performed. Pathological evaluation revealed extensive myofibroblastic reaction of the mesentery with accompanying loci of fat necrosis and areas of inflammation. A diffuse fibrotic infiltration that focally showed a ground-glass appearance was observed. The post-operative course was complicated by respiratory insufficiency and infections and the patient died 2 months after the operation.

Conclusion

Sclerosing mesenteritis that affects both the small and the large intestine is extremely rare. The disease is characterized by myofibroblastic reaction, fat necrosis and diffuse fibrosis of the mesentery. Pathological confirmation may be required for definite diagnosis. If the disease is characterized by severe and diffuse fibrosis, then the application of surgical therapy may be problematic.

Mesenteric panniculitis with pedal edema in a 33-year-old Pakistani man: a case report and literature review

Introduction

Mesenteric panniculitis is a rare pathology of unknown etiology characterized by inflammation and fibrosis in the mesentery. Its protean clinical and radiological manifestations make it a diagnostic challenge. There is no established treatment available for its management. The clinical outcome is inconsistent, with the prognosis ranging from complete resolution without any treatment to rapid progression culminating in death.

Case presentation

A 33-year-old Pakistani man presented with vague abdominal pain, an ill-defined epigastric mass and bilateral pedal edema. A detailed review of his history and laboratory investigations did not point to any diagnosis. The patient underwent an exploratory laparotomy based on the finding of mesenteric soft-tissue density on computed tomography. The laparotomy did not prove to be of any diagnostic or therapeutic value. Upon review of the pre-operative computed tomographic scan at our institution, a diagnosis of mesenteric panniculitis was made. An acceptable resolution of abdominal pain and pedal edema was attained after a 4-week trial of immunosuppressive therapy. This is the first reported case of mesenteric panniculitis with pedal edema as part of its presentation.

Conclusion

An increased awareness may lead to the development of a less invasive diagnostic approach and optimal treatment for this rarely recognized condition.

Sclerosing mesenteritis as a rare cause of abdominal pain and intraabdominal mass: a cases report and review of the literature

Sclerosing mesenteritis is a rare, benign, and chronic fibrosing inflammation disease with unknown etiology that affects the mesentery of small bowel and colon. The disease has two well-established histological types: the acute or subacute form known as mesenteric panniculitis and the chronic form known as retractile or sclerosing mesenteritis. Because the sclerosing mesenteritis is lack of special clinical manifestation and typical signs, so the patients are very easy to be misdiagnosed. The correct diagnosis of sclerosing mesenteritis depends on pathological examination and exploratory laparotomy. We report a case of sclerosing mesenteritis in a 52-year-old male who presented with chronic abdominal pain and intraabdominal mass. This patient had a long-term and heavy drinking history. He was misdiagnosed as celiac teratoma by CT examination and then underwent an exploratory laparotomy at March 2 2004. A mass, its diameter being about 5 cm, was detected in mesentery of distal ileum. Although a few small intestines tightly adhered on the mass, the involved intestine had no obstruction. The intraoperative biopsy indicated that it was an inflammatory mass. The mass and adhered intestines were removed. He was diagnosed with sclerosing mesenteritis by histopathological examination of paraffin section. After operation, this patient went well and lives without recrudescence at the time we wrote this paper.

Are tumefactive lesions classified as sclerosing mesenteritis a subset of IgG4-related sclerosing disorders?

BACKGROUND

The relationship between tumefactive lesions classified as sclerosing mesenteritis and IgG4-related sclerosing disorders (eg, lymphoplasmacytic sclerosing pancreatitis/autoimmune pancreatitis) remains uncertain.

AIMS

To review lesions coded as "sclerosing mesenteritis" for findings in keeping with IgG4-related sclerosing disorders.

METHODS

Inclusion in the study required available paraffin blocks for IgG4 staining and documentation of a mass lesion.

RESULTS

A total of nine mesenteric lesions (3-14 cm) were identified in 6 male and 3 female patients. On H&E-stained sections, all were characterised as loosely marginated fibroinflammatory processes with variable amounts of fat necrosis. Lymphocytic venulitis/phlebitis was identified in 8 of 9 cases. IgG and IgG4 expression in lesional plasma cells was assessed by immunohistochemistry. IgG4-positive plasma cells were counted in the areas of greatest density in >or=3 high power fields (HPFs). The highest number per HPF was recorded and a score assigned based on the following scale: <5/HPF, none/minimal; 5-10/HPF, mild; 11-30/HPF, moderate; >30/HPF, marked. The relative proportion of IgG4-reactive plasma cells to total IgG-positive plasma cells was assessed. IgG4-reactive plasma cells ranged from 0 to >100 in the most dense zones (3 cases, none/minimal; 4 cases, moderate; 2 cases, marked).

CONCLUSIONS

Although this study is limited by small numbers, findings suggest that some tumefactive lesions regarded as sclerosing mesenteritis may be a subset of IgG4-related sclerosing disorders.

[Successfully treated case of postoperative mesenteric panniculitis]

Mesenteric panniculitis can develop in every patient after abdominal surgery. The clinical and pathological signs are usually vague, so different therapeutic approaches are recommended at various stages of the disease. While some authors suggest that these stages are different manifestations of the the same disease, others claim that the various stages represent the progression of a single entity. We report a case of a 65 year-old male patient with mesenteric panniculitis and fibrosis, which developed after laparoscopic sigmoid resection first, and required a Hartmann's procedure finally. The disease developed once again after the elective reconstruction of the colon. This time surgical intervention was not possible and he was treated conservatively with intravenous steroids, antibiotics, parenteral nutrition and continuous nasogastric tube. The patient gradually recovered in three weeks time. We report this successful treatment, and review the relevant literature.

Mesenteric Lipodystrophy of the Left Colon

Mesenteric lipodystrophy is a rare condition characterized by tumor-like expansion of the mesocolon. The etiology remains obscure, but autoimmunity, abdominal trauma, abdominal surgery, and ischemic injury have all been postulated. To our knowledge, there have been no previous reports of synchronous mesenteric lipodystrophy and angiodysplasia. Whether these are independent or associate entities remains unknown. We present the clinical, radiological, and pathological findings of such a case.

Occasional finding of mesenteric lipodystrophy during laparoscopy: A difficult diagnosis

Mesenteric lipodystrophy is a rare pathological condition affecting the mesentery. Its initial presentation is typically asymptomatic. Pathological characteristics are unspecific, and generally attributed to inflammation, unless the diagnosis is suspected. Laparoscopy done for other reasons has been, as in this case, unsuccessful in providing evidence for the correct diagnosis, thus requiring laparotomy due to lack of diagnostic tissue. After 6 mo no further medical therapy is required, as the patient remains asymptomatic. Discussion of this case and a brief review of the literature are presented in the following paragraphs.

Mesenteric panniculitis of the sigmoid colon: a case report and review of the literature

Introduction

Mesenteric panniculitis of the sigmoid colon is a rare occurrence in surgical practice. The aim of this article is to present a case of mesenteric panniculitis of the sigmoid colon and a short review of the literature.

Case presentation

We reviewed the hospital record of a 63-year-old man who presented with a palpable mass in the left abdomen and clinical signs of a partial bowel obstruction. The pre-operative impression was a possible cancer of the sigmoid colon. A laparotomy was performed through a midline incision. The mesentery was found to be markedly thickened, constricted and puckered. The normal architecture of the adipose tissue had been lost and replaced with an irregular nodular mass. The microscopic pathologic sections demonstrated a chronic reactive inflammatory process with an exuberant proliferation of fibroblasts and fibrocytes. The adipose tissue contained scattered areas of steatonecrosis with foci of lipid-laden macrophages, lymphocytes and plasma cells. The sigmoid colon and its mesocolon were resected. The postoperative course was uneventful and the patient was discharged in good condition, and followed up for the next two years.

Conclusion

Mesenteric panniculitis of sigmoid is an extremely rare entity of unknown origin in which the normal architecture of the mesentery is replaced by fibrosis, necrosis and calcification. On gross examination the alterations may be mistaken for a neoplastic process. A frozen section may be necessary for confirmation of the diagnosis. When the advanced inflammatory changes became irreversible and bowel obstruction occurs, resection may be indicated.

Sclerosing mesenteritis: clinical features, treatment, and outcome in ninety-two patients

BACKGROUND & AIMS

Sclerosing mesenteritis is a rare non-neoplastic disease that affects the small bowel mesentery with chronic fibrosing inflammation. There are few data on the natural history and therapeutic options for this condition.

METHODS

We performed a retrospective and prospective study to describe the clinical characteristics, therapy, and outcome of all cases of sclerosing mesenteritis diagnosed at the Mayo Clinic, Rochester, from 1982-2005.

RESULTS

Ninety-two cases were identified; 70% were male, with a median age of 65 years (interquartile range, 55-72). Common presenting symptoms included abdominal pain in 70%, diarrhea in 25%, and weight loss in 23%. Treatment included medical therapy alone in 26%, surgery alone in 13%, surgery followed by medical therapy in 9%, and 52% received no treatment. Ten percent responded to surgery alone, 20% responded to additional medical treatment after surgery, and 38% responded to medical therapy alone. Tamoxifen in combination with prednisone was used in 20 patients, and 60% improved. Non-tamoxifen-based regimens were used in 12 patients, and 8% improved. Eighteen deaths were noted during the study period, and 17% were attributed to complications of sclerosing mesenteritis or its treatment.

CONCLUSIONS

Although a relatively benign condition, sclerosing mesenteritis can have a prolonged debilitating course with a fatal outcome. Our results suggest that symptomatic patients might benefit from medical therapy, particularly tamoxifen and prednisone combination treatment. Long-term follow-up is needed to substantiate these results.

Gastrointestinal stromal tumors: differential diagnosis

Availability of KIT tyrosine kinase inhibitors for specific treatment of GISTs has magnified the importance of accurate differential diagnosis of GIST from other tumors occurring in the GI tract and abdomen. The general problems in this distinction include histological mimicry of other mesenchymal tumors with GIST, occasional KIT-negativity of GIST, and KIT-positivity of non-GISTs. Up to 5% to 10% gastric GISTs and <2% of intestinal GISTs can be KIT-negative. The identification of these tumors as GISTs is based on knowledge of the spectrum of GIST morphology, and can be supported by molecular diagnosis of KIT and PDGFRA mutations (the latter pertain to gastric tumors). True smooth muscle tumors (rare in GI tract except in esophagus and colon) can be separated from GISTs by the eosinophilic tinctorial quality of tumor cells, positivity for smooth muscle markers, and negativity for KIT. Desmoids can form large GIST-like masses, but are composed of spindled or stellate-shaped cells in a densely collagenous stroma. Negativity for KIT and nuclear positivity for beta-catenin are differentiating features. GI schwannomas, melanoma, and rare primary clear cell sarcoma are S100-positive, usually with characteristic histology. The latter two can be KIT-positive. KIT-positive non-GISTs include some sarcomas, especially angiosarcoma and Ewing sarcoma, extramedullary myeloid tumor, seminoma, and a few carcinomas, notably small cell carcinoma of lung. Spurious KIT-positivity, seen with some polyclonal KIT antibodies, has been a source of confusion leading to probable false-positive results in fibroblastic tumors and occasional other sarcomas, such as leiomyosarcomas. Integration of histological features with carefully standardized immunohistochemistry, supported by KIT and PDGFRA mutation analysis, is the cornerstone of state-of-the art differential diagnosis of GIST. To comprehensively capture all GISTs, KIT immunostains should be performed on all unclassified epithelioid and mesenchymal tumors of the abdomen. This is a US government work. There are no restrictions on its use.

Retractile mesenteritis presenting as protein-losing gastroenteropathy

Retractile mesenteritis is a rare, idiopathic condition characterized by nonspecific inflammation of the mesenteric adipose tissue. The majority of patients present with abdominal pain and/or a palpable mass. In the present report, a 68-year-old man with peripheral edema and mild hypoalbuminemia is presented. Protein-losing gastro-enteropathy was confirmed with an abnormal stool alpha1-antitrypsin clearance test and retractile mesenteritis was diagnosed at laparoscopy. This rare condition may respond to therapy with corticosteroids, azathioprine, cyclophosphamide, colchicine, progesterone, tamoxifen or thalidomide. Gastroenterologists should consider the diagnosis of protein-losing enteropathy in patients who present with unexplained peripheral edema or hypoalbuminemia. The test of choice to confirm this diagnosis is the stool alpha1-antitrypsin clearance test.

[Etiologic spectrum of mesenteric panniculitis: report of 7 cases]

OBJECTIVE

Mesenteric panniculitis is a rare disorder characterized by nonspecific inflammation and/or necrosis and/or fibrosis in the adipose tissue of the bowel mesentery. Its signification, primary or associated with other diseases, is a subject of controversy.

METHODS

A descriptive and retrospective study of patients with an abdominal CT examination showing features of mesenteric panniculitis and for whom biopsy with immunohistochemical examination was obtained in all cases.

RESULTS

Seven patients were enrolled (4 men and 3 women) with a median age of 62,1 years. None of the patients without an identified etiology had a history of abdominal surgery. An associated disease was identified in 4 cases: breast cancer (1), non-Hodgkin's lymphoma based on peripheric lymph nodes biopsy (2) and cryoglobulinemic vascularitis based on renal biopsy (1). In the 3 remaining cases, isolated mesenteric panniculitis was the only abnormality despite thorough imaging and pathologic investigations.

CONCLUSION

Except an obvious malignancy context or a history of abdominal surgery, a pathologic examination of the mesenteric panniculitis lesions is necessary, especially to eliminate another mesenteric disorder. Mesenteric panniculitis is often associated with lymphoma.

Mesenteritis osificante

We report a case of heterotopic bone formation in the mesentery. A 64-year-old man presented with abdominal pain and stiffness two months after undergoing several surgical interventions for hemorrhagic colitis. The diagnosis was heterotopic mesenteric ossification. We describe the imaging findings and review the literature.

Sclerosing mesenteritis presenting with small bowel obstruction and subsequent retroperitoneal fibrosis

Sclerosing mesenteritis is a rare inflammatory disease of the bowel mesentery of unknown aetiology. It poses a diagnostic challenge for clinicians, as it can be mistaken for malignancy. We report a case of sclerosing mesenteritis initially presented with abdominal pain, tender abdominal mass and small bowel obstruction. Emergency laparotomy revealed fibrous thickening of the small bowel mesentery mimicking small bowel lymphoma. An ileo-ileal bypass procedure was performed. Six months later, the patient developed retroperitoneal fibrosis, manifesting as bilateral obstructive uropathy. Our case is unique, as it describes retroperitoneal fibrosis developing in a patient with small bowel retractile mesenteritis, with no evidence of colonic or other anatomical involvement. Furthermore, the patient had no risk factors for this condition. We conclude that the presence of sclerosing mesenteritis should cue clinicians to search for other coexisting inflammatory disorders that can have serious sequelae.

Sclerosing mesenteritis associated with giant-cell temporal arteritis

A 72-year-old man presented with a history of progressive abdominal pain associated with simultaneous headache, constitutional syndrome, and weight loss. A CT scan demonstrated sclerosing mesenteritis (SM). A surgical biopsy of mesenteric tissue excluded malignancies and a temporal artery biopsy showed giant-cell arteritis, establishing the diagnosis of SM associated with giant-cell temporal arteritis (GCA). Both entities responded well to steroid therapy and relapsed simultaneously after steroid withdrawal. This association may be fortuitous, but it can also represent a unique clinical setting. We suggest ruling out GCA every time a SM is encountered in the appropriate clinical setting (i.e., in elderly patients with other symptoms and signs suggestive of GCA). A temporal artery biopsy may be systematically considered in these patients.

The CT appearances of sclerosing mesenteritis and associated diseases

Sclerosing mesenteritis is characterized by non-specific inflammation of the mesenteric fat associated with variable amount of fibrosis. The aetiology is unclear; the pathogenesis is obscure, and even its nomenclature remains variable. It is a rare condition with imaging features that can be mistaken either for a mesenteric neoplasm or for a wide variety of non-neoplastic inflammatory conditions. Knowledge of the imaging features of this condition may prevent unwarranted aggressive therapy. This review discusses the pathogenesis, clinical manifestations of this condition, as well as illustrating the characteristic computed tomography (CT) features of sclerosing mesenteritis. A rational approach to the differential diagnosis is discussed.

Role of adipose tissue as an inflammatory organ in human diseases

Reviews on the inflammatory role of adipose tissue outside the field of metabolism are rare. There is increasing evidence provided by numerous basic research studies from nearly all internal medicine subspecializations that adipocytes and adipocytokines are involved in primary inflammatory processes and diseases. Therefore, it is the aim of the present review to discuss and to summarize the current knowledge on the inflammatory role of adipocytokines and special types of regional adipocytes such as retroorbital, synovial, visceral, subdermal, peritoneal, and bone marrow adipocytes in internal medicine diseases. Future clinical and therapeutic implications are discussed.

Idiopathic orbital inflammation with sclerosing mesenteritis: a new association?

A 70-year-old man, who was recently diagnosed with sclerosing mesenteritis following an abdominal biopsy, presented with an acute onset of left upper eyelid swelling, moderate ptosis, mild chemosis and restriction of movements. A computed tomography scan showed an enlarged lateral rectus muscle with surrounding soft tissue changes. A diagnosis of orbital inflammation manifesting as myositis was made and the patient was commenced on high-dose prednisolone, which showed a rapid response. It is believed that this may be a new association similar to that previously reported with retroperitoneal fibrosis and orbital inflammation.

Clinical characteristics of Chinese retractile mesenteritis: an analysis of 47 cases

AIM: To summarize the clinical characteristics of Chinese retractile mesenteritis.

METHODS: Three patients diagnosed with retractile mesenteritis in our hospital and 44 ones reported in 33 articles were concluded in this study. The clinical data, including the ages, sex, predisposing factors, clinical manifestations, diagnosis and treatment, locations and sizez of the lesions, and prognosis, were analyzed.

RESULTS: Chinese retractile mesenteritis mainly occurred in middle-aged and old patients (mean age: 46 ± 18), among which the male and females covered an equivalent proportion. Its dominant symptoms were bellyache and celiac mass. The mean value of long diameter was more than 5 cm (mean: 8.5 ± 3.5 cm) in majority. The focus located in the mesentery of small intestine most frequently, then came to ascending colon, transverse colon, descending colon sigmoid colon and epiploon, orderly.

CONCLUSION: Non-specific symptoms and physical signs lead to a high rate of misdiagnosis in patients of retractile mesenteritis. The accurate diagnosis for retractile mesenteritis depends on pathological and surgical examination.

Sonographic findings of mesenteric panniculitis: correlation with CT and literature review

PURPOSE

To evaluate the sonographic findings of mesenteric panniculitis (MP) and correlate them with CT findings.

METHODS

We retrospectively evaluated the clinical, CT, and sonographic findings in 26 cases of MP in our hospital between January 1997 and July 2003. We also reviewed the sonographic features of MP previously described in the literature.

RESULTS

The sonographic findings were well correlated to CT in 24 of 26 patients (92%). In these 24 cases, abdominal sonographic examination revealed a hyperechogenic, well-defined fatty mass (corresponding to the pseudocapsule CT sign) in the root of the mesentery, displacing the bowel loops. We found a clear interface between MP and normal intra abdominal fat. Examination with color Doppler sonography revealed the nondeviated mesenteric vessels within the mass. The persence of MP improved sonographic transmission in 9 obese patients and enabled the retroperitoneal vessels to be clearly visualized. Sonography was unable to demonstrate the preservation of the fat nearest the mesenteric vessels corresponding to the "fatty halo" sign on CT.

CONCLUSIONS

Sonography is useful in the diagnostic workup for MP. The characteristic sonographic features of MP (well-defined mass, homogeneous hyperechogenicity of the mass, nondeviated vessels within the mass, and displaced bowel loops) correlate well with CT findings.

Incidental calcifying fibrous tumor of the stomach presenting as a polyp

Calcifying fibrous tumor (CFT) is an uncommon lesion of uncertain cause and pathogenesis that has a unique histological appearance. These lesions are described mainly in the subcutaneous or deep soft tissues, followed by subserosal locations. Intrinsic visceral CFT is extremely rare. Herein is described a rare case of CFT that involved the gastric wall, along with a review of the literature. An incidental small polypoid lesion was excised during urgent surgery for penetrating injury at the lesser curvature in a 25-year-old man, previously healthy. The lesion was a well-demarcated, small (10 mm) tumor that occupied the submucosa. The characteristic histopathological features and the presence of spindle cells that express factor XIIIa allowed a diagnosis of CFT to be made. The present case and the review revealed that, despite their frequent subperitoneal location, intra-abdominal CFT might present as intrinsic visceral lesions and might be found incidentally. These lesions tend to be smaller when compared to their symptomatic counterparts. The diffuse factor XIIIa expression in CFT might be useful to differentiate this entity from other intra-abdominal soft-tissue tumors in problematic cases. Although rarity of intrinsic visceral CFT necessitates new cases to determine their exact biological behavior, the present case highlights their presence in the stomach as a symptomless small polypoid lesion.

Acute epiploic appendagitis and its mimics

Acute epiploic appendagitis most commonly manifests with acute lower quadrant pain. Its clinical features are similar to those of acute diverticulitis or, less commonly, acute appendicitis. The conditions that may mimic acute epiploic appendagitis at computed tomography (CT) include acute omental infarction, mesenteric panniculitis, fat-containing tumor, and primary and secondary acute inflammatory processes in the large bowel (eg, diverticulitis and appendicitis). Whereas the location of acute epiploic appendagitis is most commonly adjacent to the sigmoid colon, acute omental infarction is typically located in the right lower quadrant and often is mistaken for acute appendicitis. It is important to correctly diagnose acute epiploic appendagitis and acute omental infarction on CT images because these conditions may be mistaken for acute abdomen, and the mistake may lead to unnecessary surgery. The CT features of acute epiploic appendagitis include an oval lesion 1.5-3.5 cm in diameter, with attenuation similar to that of fat and with surrounding inflammatory changes, that abuts the anterior sigmoid colon wall. The CT features of acute omental infarction include a well-circumscribed triangular or oval heterogeneous fatty mass with a whorled pattern of concentric linear fat stranding between the anterior abdominal wall and the transverse or ascending colon. As CT increasingly is used for the evaluation of acute abdomen, radiologists are likely to see acute epiploic appendagitis and its mimics more often. Recognition of these conditions on CT images will allow appropriate management of acute abdominal pain and may help to prevent unnecessary surgery.

From the archives of the AFIP: benign fibrous tumors and tumorlike lesions of the mesentery: radiologic-pathologic correlation

Mesenteric fibromatosis, sclerosing mesenteritis, inflammatory pseudotumor, and extrapleural solitary fibrous tumor constitute a loosely associated group of benign fibrous tumors and tumorlike lesions of the mesentery. These lesions are linked histologically by the presence of fibroblasts or fibrosis and anatomically by their location within the mesentery. Although rare, and distinctly different in pathogenesis and biologic behavior, these fibrous lesions have pathologic and radiologic features that overlap with one another and with more common neoplastic and nonneoplastic lesions of the mesentery. Mesenteric fibromatosis is a locally aggressive, benign proliferative process that may occur sporadically or in association with familial adenomatous polyposis. It most frequently manifests as a focal mesenteric mass and may simulate lymphoma, metastatic disease, or a soft-tissue sarcoma. Sclerosing mesenteritis is a rare idiopathic disorder that most commonly produces a stellate mass within the mesentery and should be differentiated from metastatic disease, specifically metastatic carcinoid, because it frequently responds to conservative or medical management. Inflammatory pseudotumor (inflammatory myofibroblastic tumor) is a benign, chronic inflammatory disorder of unknown cause that manifests as a solid mesenteric mass, indistinguishable from malignancy. Extrapleural solitary fibrous tumor is a tumor of submesothelial origin that is identical to the solitary fibrous tumor of the pleura. When located in the mesentery or peritoneal cavity, extrapleural solitary fibrous tumor has an imaging pattern that must be differentiated from metastatic disease, soft-tissue sarcomas, and other benign and malignant neoplasms of the mesentery and peritoneum. Knowledge of this group of benign fibrous tumors and tumorlike lesions of the mesentery is important in the preoperative evaluation of a mesenteric mass.

Heterotopic mesenteric ossification: a distinctive pseudosarcoma commonly associated with intestinal obstruction

Heterotopic mesenteric ossification (HMO) is a rare intraabdominal bone-producing pseudosarcoma with fewer than 14 reported cases in the literature. We report our experience with 6 additional cases, all of which were referred to us with a diagnostic consideration of extraskeletal osteosarcoma (EO) or "sarcoma" and emphasize features which distinguish HMO from EO. Six intraabdominal lesions coded as "heterotopic mesenteric ossification," "ossifying pseudotumor," or "reactive myofibroblastic proliferation with ossification" were retrieved from our consultation files. Clinical follow-up information was obtained. Lesions occurred exclusively in males, with a mean patient age of 49 years (range, 22-72 years). The tumors occurred in the mesentery (N = 4), omentum (N = 1), or both (N = 1) and were preceded by significant abdominal surgery (4 cases) or trauma (1 case) in all but 1 case. Five patients presented with bowel obstruction and 1 with abdominal sepsis. Tumors were difficult to precisely measure; the mean size of the resection specimens was 11.8 cm (range, 3.5-20 cm). Grossly, the tumors resembled fat necrosis and often cut with a gritty sensation. Microscopically, all lesions demonstrated an exuberant, reactive (myo)fibroblastic proliferation resembling nodular fasciitis, with extensive hemorrhage and fat necrosis. All tumors produced abundant bone and osteoid, often "lace-like," and 2 contained cartilage. The proliferating (myo)fibroblasts, osteoblasts, and chondroblasts were mitotically active but cytologically bland. Follow-up (4 cases; mean, 47.3 months; range, 5-120 months) showed 3 patients alive without disease and 1 dead of unrelated causes. One case was recent. HMO is a distinct intraabdominal ossifying pseudotumor that typically occurs in males, almost always after surgery or abdominal trauma, and frequently presents with symptoms of intestinal obstruction. This clinical history, presence of clearly reactive zones resembling nodular fasciitis, thick osteoid, and absence of nuclear atypia, necrosis, and atypical mitotic figures allow the distinction of HMO from its most important morphologic mimic, EO.