Malignant mesenchymoma of mesentery. A controversial entity

We report a case of malignant mesenchymoma developed in the mesentery in a 62-year-old man with no past history. It was an huge mass in the mesentery of the ileum. The tumor was composed of areas of chondrosarcoma and rhabdomyosarcoma in addition to an undifferentiated fusiform component. Malignant mesenchymoma is a rare sarcoma occurring preferentially in the retroperitoneum or the thigh. The location in the mesentery is exceptional. Malignant mesenchymoma is discussed more particularly with dedifferentiated liposarcoma with heterologous elements. The patient is alive without recurrence three years after surgery.     

Splanchnic slowly adapting mechanoreceptors with punctate receptive fields in the mesentery and gastrointestinal tract of the cat

1. A class of slowly adapting mechanoreceptors with A-delta and C fibres running in the splanchnic nerves of cats is described.2. The mechanoreceptors have punctate regions of mechanical sensitivity at macroscopic vascular branching points and have been found in the lesser omentum, the mesentery of the gall-bladder, porta hepatis, portal vein, pancreas, spleen and the duodenum, jejunum, ileum, colon and their mesenteries.3. The receptive fields of these mechanoreceptors vary considerably in size in the different regions. The largest receptive fields were found in the small intestinal mesentery and consisted of up to seven points of mechanical sensitivity at vascular divisions, each separated by distances of a few up to about 40 mm. The smallest receptive fields were single or double points of mechanical sensitivity which were most commonly found in relation to the portal vein in the root of the mesentery.4. Maintained stretch of the receptive field elicited a train of impulses which had phasic and tonic components. The tonic discharge was sometimes maintained for more than 1 min.5. Distension of a neighbouring viscus often caused a discharge which had a phasic component and a variable tonic component. The occurrence of the latter appeared to depend on the relative positions of the bowel and mesentery, and was probably associated with a change in tension on the mesentery.6. Occlusion of the portal vein resulted in some units in a discharge which began soon after the start of the occlusion.7. The receptors do not appear to be affected by acid, hypoxia or hypercapnia.     

Abdominal actinomycosis associated with a sigmoid colon perforation in a patient with a ventriculoperitoneal shunt

Abdominal actinomycosis causing hydronephrosis in a patient with a ventriculoperitoneal shunt is very rare. A 27- year-old female patient was admitted complaining of lower abdominal pain. She had undergone ventriculoperitoneal shunt surgery 10 years ago. Abdominal Ultrasonography and a CT scan demonstrated an inflammatory mass in the lower left quadrant of the abdomen causing obstructive hydroureter and hydronephrosis. Laparotomy revealed a diffusely infiltrating mass involving the small bowel, mesentery, and sigmoid colon, and a 1cm perforation in the sigmoid colon. Actinomycosis was diagnosed upon histological examination. After treatment with antibiotics and surgery, the patient's condition improved.     

Perforated jejunal diverticular disease: a diagnostic pitfall at frozen section of a mesenteric mass for adenocarcinoma of the stomach

This case illustrates an unusual associated pathology in a patient with gastric adenocarcinoma. A 79-year-old male with biopsy-proven gastric cancer was found intra-operatively to have a hard mass in the mesentery involving proximal jejunum. A segment of small bowel was resected and a frozen section was requested to confirm disseminated malignancy. After a benign diagnosis was rendered, a total gastrectomy for adenocarcinoma was then performed. The jejunum contained two diverticula, one of which had perforated and this was the cause of the intra-abdominal mesenteric pathology. Jejunal diverticular disease is highlighted and reviewed.     

Idiopathic enterocolic lymphocytic phlebitis: a rare cause of ischemic colitis.

We report on a 74-year-old female patient who was admitted to the hospital because of abdominal pain. She underwent a colonoscopy and a stenosing mass was found in the cecum. Histologic findings in the biopsy specimens were consistent with ischemic colitis. Due to clinical symptoms and the endoscopic and radiologic findings that roused the suspicion that the patient was suffering from a malignant tumor, a right hemicolectomy was performed. Histology of the resection specimen disclosed an inflammation of the veins. It was characterized by a predominantly lymphocytic infiltration of the vessels affecting the veins of the colonic wall and the mesentery. Furthermore, secondary thrombosis with focal venous occlusion was observed. The colon showed extensive ischemic colitis with focal transmural coagulation necrosis. The disease was considered to be idiopathic lymphocytic phlebitis, which is a rare disease of unknown origin. Our patient is well and alive after more than 1 year, supporting the notion that the disease shows a benign course after surgery.     

Extra-uterine low grade stromal sarcoma with JAZF1–PHF1 gene fusion presenting as a mesenteric mass

This case illustrates a low-grade endometrial stromal sarcoma presenting as an intra-abdominal mass. Intra-operatively, this was thought to arise within the mesentery and was classified as a mesenteric tumour. The solid and cystic mass was composed of relatively uniform cells organized in sheets. Up to 8 mitoses per high power field was noted. The stroma although scanty, contained both delicate capillary-type and more arteriolar-like vessels. Admixed with the tumour cells were smaller cells reminiscent of endometrial stromal granulocytes. The tumour was positive for: WT1, oestrogen receptor (ER), CD10, vimentin, and focally for progesterone receptor (PR), and very occasional cells for smooth muscle actin. Fluorescence in situ hybridization (FISH) showed the presence of JAZF1 and PHF1 genetic rearrangement.This confirmed a diagnosis of extra-uterine low-grade endometrial stromal sarcoma. It is unsure whether this represents a primary or secondary lesion as the patient had a previous hysterectomy for unknown pathology.     

Well‐differentiated papillary mesothelioma,possibly giving rise to diffuse malignant mesothelioma: A case report

Well‐differentiated papillary mesothelioma (WDPM) is a distinct subtype of mesothelial tumor from diffuse malignant mesothelioma (DMM), with an uncertain malignant potential. The relationship between WDPM and DMM, with regard to the ability of the former to develop into the latter, is also unknown. A 58‐year‐old woman, diagnosed with a rectal carcinoid tumor, underwent removal of the lymph nodes via the abdomen in 2004. A large number of white miliary nodules were identified on the mesentery and peritoneum, which were histologically diagnosed as WDPM. No further therapy was administered, but the patient was followed‐up using imaging methods. Seven years later, an abdominal wall mass was discovered using positron emission tomography‐computed tomography, and a laparotomy biopsy was performed. DMM was diagnosed, because mesothelioma with extended invasion had been histologically identified. Mesothelioma similar to papillary proliferation was present on the outer layer of the peritoneum, and an infiltrating lesion with continuous restiform or solid‐like structures was noted. WDPM was believed to have undergone malignant transformation. Compared to DMM, WDPM has a good prognosis and is considered a benign or borderline neoplasm. Our findings suggest that WDPM does have malignant potential, however, because histological findings indicated a malignant transformation of WDPM to DMM.     

捻转补泻手法对大鼠小肠系膜透明窗肥大细胞的影响

健康雄性大鼠46只随机分为捻转泻法、补法、电针、捆绑对照和空白对照5组。大鼠捆梆于鼠台,分别行捻转补泻手法和电针,针右“足三里”10分钟,实验6天后取空、回肠系膜铺片,醛品红—橙黄G染色,10×40倍光镜观片。结果发现,对小肠系膜透明窗肥大细胞脱颗粒率的影响,捻转泻法优于补法,手针总体作用优于电针,对空肠作用优于回肠。捆绑大鼠导致肥大细胞数目减少,捻转泻法可使其回升,电针则使之进一步下降。     

Localized malignant mesenteric mesothelioma causing small bowel obstruction

Malignant mesothelioma is an uncommon lethal neoplasm in the serous membrane in which peritoneal mesothelioma is a rarer form. Herein is reported a case of malignant mesothelioma presenting as a localized mass inside the mesentery causing focal luminal obstruction of the small intestine. The diagnosis of malignant mesothelioma was obtained on repeat double balloon endoscopic biopsy. Partial resection of the small intestine along with the mesentery was performed, followed by a course of chemotherapy. No relapse of the disease has been found in the 8 months' follow up radiologically. To the best of the authors' knowledge this is the first reported case of localized malignant mesothelioma arising inside the mesentery. Mesothelioma should be considered as the differential diagnosis when small bowel obstruction occurs with unknown primary neoplasm.     

Effect of implantation site on hepatocytes heterotopically transplanted on biodegradable polymer scaffolds

We investigated the engraftment of heterotopically transplanted hepatocytes in three sites: the subcutaneous space, the small intestinal mesentery, and the omentum to determine the optimal location for tissue-engineered liver constructs. Hepatocytes were isolated from inbred Lewis rats and placed on polymer constructs. Cell-polymer constructs were implanted into the subcutaneous space of the abdominal wall, the small intestinal mesentery, and the omentum of Lewis rats. One group of rats had undergone previous portacaval shunt. Animals were killed 2 or 4 weeks after implantation and the constructs were analyzed for engraftment, using computer-assisted morphometric analysis. Engraftment was greatest in the omentum with less engraftment in the mesentery. There was minimal engraftment in the subcutaneous space in all specimens. Prior portacaval shunt increased engraftment in the mesentery and the omentum, but not the subcutaneous space. The omentum is the most favorable bed for engraftment of hepatocyte-polymer tissue-engineered constructs and the addition of a portacaval shunt increases survival of transplanted hepatocytes in the omentum and mesentery.     

Solitary neurofibroma of the mesentery: report of a case and review of the literature

Neurofibromas of the gastrointestinal tract are usually associated with neurofibromatosis type 1 (Nfl), or they are exclusive manifestations of the so-called "familial intestinal neurofibromatosis". Gastrointestinal neurofibromas can rarely occur as sporadic lesions in the jejunum and stomach, and only exceptionally in the mesentery. A critical review of the literature revealed that only seven cases of solitary neurofibromas (SNFs) of the mesentery (six in the ileal mesentery; one in the gastrocolic mesentery) have been reported in patients without stigmata of Nf1. We report the clinicopathologic features of an additional case of SNF of the ileal mesentery, incidentally found in a patient with an advanced gastric carcinoma. Since there is increasing evidence that some patients may have some features of Nf1, including dermal or nodular SNFs alone - limited to one or more body segments - (segmental Nf1), the possibility that SNFs of the mesentery may also represent a segmental manifestation of Nf1 is postulated.     

Paraganglioma of the mesenterium: a case report

Extra-adrenal paragangliomas constitute 10 % or less of phaeochromocytomas/paragangliomas. Even rarer is the occurrence of paragangliomas outside the usual distribution of paraganglionic tissue. We report a case of extra-adrenal paraganglioma occurring in the small intestine mesentery in a 65-year-old man. To our knowledge, there are only seven case reports of paraganglioma occurring in this non-typical site. Computed tomography showed a solid expansive non-homogenously enhancing mesenteric mass, measuring 10 x 8 cm with peripheral cystic component. Histologically, the tumour had a typical organoid "zellballen" pattern, showed immunohistochemical positivity for synaptophysin, neuron specific enolase, CD-56, chromogranin, and focally vimentin, and was cytokeratin and EMA negative. S-100 protein stained few sustentacular cells. The patient was free from recurrence or metastasis three months after tumour resection. Although rare, paraganglioma should be included in the preoperative differential diagnosis of solid mesenteric tumours, to prevent any potential life-threatening event peroperatively in the case of a catecholamines-producing tumour.     

Primary mucosa-associated lymphoid tissue lymphoma of the prostate: tumor relapse 7 years after local therapy

Primary mucosa-associated lymphoid tissue (MALT) lymphoma of the prostate is rare, and only five cases have been reported. Reported herein is a new case that has involved a 9 year follow up. A 79-year-old man was treated with transurethral resection (TUR) for a mass of the right prostatic lobe, and followed up under a diagnosis of benign prostatic hyperplasia with atypical lymphoid infiltration. Seven years later TUR was again performed for a right lobe mass. The lesion was diagnosed as a relapsed MALT lymphoma after detailed histological and immunoglobulin heavy chain gene analyses of the initial and relapsed lesions. Interestingly, lymphoepithelial lesions were observed only infrequently in this tumor. The API2-MALT1 fusion, a gene alteration specific to MALT lymphoma, was absent. The patient had stage IA disease at the time of tumor relapse, and has been alive and well for the 2 years after the second TUR. The present case suggests that despite tumor recurrence, prostatic MALT lymphoma is indolent, and function-preserving therapy is warranted.     

Amplification of 2p13-16 in a case of extranodal large cell diffuse B-cell lymphoma

Comparative genomic hybridisation (CGH) allows to detect genetic abnormalities associated with poor prognosis in subset of patients with diffuse large B-cell lymphoma (DLBCL). Amplification of 2p13-16 represents an adverse genetic sign especially in extranodal DLBCL. In the present case, 2p13-16 amplification was revealed by CGH in extranodal DLBCL. It was localized in the mesentery and remained resistant to the chemotherapy (CHOP). A patient, 72-year-old female, died 10 weeks after the diagnosis had been made. Rapid lethal course of the disease confirms poor outlook for patients with 2p13-16 and supports a role of CGH as a sensitive method in prognosis for patients with DLBCL.     

Neuron-specific enolase-producing leiomyosarcoma of the mesentery

A case of neuron-specific enolase (NSE)-producing leiomyosarcoma arising in the mesentery of a 62-year-old female is presented. Preoperatively, serum level of NSE was markedly elevated. A well-defined but unencapsulated tumor measuring 14 x 12 x 9 cm was histologically characterized by a fascicular or herring-bone arrangement of atypical spindle or oval tumor cells with vesicular cigar-shaped nuclei, inconspicuous nucleoli and abundant clear to brightly eosinophilic cytoplasm. Immunohistochemically, the tumor was positive for vimentin, alpha-smooth muscle actin, muscle actin, desmin, and gamma-NSE. Postoperatively, serum level of NSE decreased to within normal range. The NSE levels were, however, elevated again as metastatic lesions in the liver had enlarged. The patient died of the liver metastases 10 months after surgery. Serum NSE level can be a useful index of tumor extent and for monitoring treatment of some patients with leiomyosarcoma.     

Uterus-like mass of the small bowel mesentery

A case of a uterus-like mass arising from the mesentery is reported. A mass measuring 14x11 cm was noted in the small bowel mesentery of a 59-year-old woman. Histologically, the lesion consisted of endometrial-type and fallopian tube-type mucosa surrounded by thick bundles of smooth muscle cells. Since the first report by Cozzutto in 1981, 10 cases of uterus-like mass, that included seven ovarian and three extraovarian cases, have been reported. To our knowledge, the present lesion was the first case originating from the mesenteric region. Three hypotheses of this rare lesion: (i) congenital anomaly; (ii) metaplasia; and (iii) heterotopia theories are reviewed.     

Distribution of fibronectin on the migratory pathway of primordial germ cells in mice

The distribution and localization of fibronectin (FN) on the migratory pathway of primordial germ cells (PGCs) in mouse embryos were studied immunocytochemically at the light and electron microscopic levels. In embryos 9.5 to 11.0 days of gestation, the dorsal mesentery as the final region through which PGCs migrate was rich in FN. At this stage, migrating PGCs often showed amoeboid features with pseudopods in contact with neighboring mesentery (mesenchymal) cells. With the electron microscope, the reaction product to FN was visualized on the surfaces of somatic cells and of PGC pseudopods and at the site of contact between PGCs and somatic cells. Abundant extracellular FN was also found, probably binding with the extracellular matrices. By 11.5 to 12.0 days, when PGCs had arrived in the gonadal anlage, FN reaction had weakened or disappeared in the dorsal mesentery. Thus, the results suggest that FN plays a significant role in the migration of PGCs at least in the last portion of the migratory pathway.     

Arterial supply to the pig intestine: an unusual pattern in the mesentery

The arrangement of arteries in the mesentery in pigs was studied with latex casts and light microscopy. Arterial arcades, which are characteristic of the mesentery in man and other species, are absent. Instead, a narrow band of numerous, anastomosing arteries gives rise to up to about 500 bundles of arteries and accompanying veins, which radiate out in the mesentery. Each bundle contains up to 30 arteries, but these recombine as they approach the jejunum, and form 1-4 arteriae rectae. The significance of the very large number of small arteries in the mesentery is not known, but they may play a role in the control of blood pressure in the intestinal wall, or as sites of countercurrent exchange.     

Endometrial Stromal Sarcoma Presenting as Prevesical Mass Mimicking Urachal Tumor

Endometrial stromal sarcoma (ESS) is a mesenchymal neoplasm that usually occurs as a primary tumor of the uterine corpus, but rarely arises in other sites, such as the ovary, pelvic cavity, mesentery, omentum and intestine. Herein, we present a rare case of low-grade ESS presented as prevesical mass. A 60-yr-old woman who had undergone total hysterectomy for endometriosis eleven years ago was presented with incidentally detected prevesical pelvic mass. Since malignant transformation of urachal remnants was possible, the mass was suspected to be a urachal tumor. Extraction of the mass was performed, and the histopathologic diagnosis was low-grade ESS. In summary, prevesical tumor is rare but in patients with endometriosis, we suggest endometriosis and its possible malignant changes should be taken into account in the differential diagnosis of prevesical mass.