Malignant myopericytoma originating from the colon: A case report

BACKGROUND Myopericytoma is a benign tumor that typically occurs within subcutaneous tissue and most often involves the distal extremities,followed by the proximal extremities,neck,thoracic vertebrae and oral cavity.Complete resection is often curative.Malignant myopericytoma is extremely rare and has a poor prognosis.Here,we report for the first time a case of malignant myopericytoma originating from the colon.CASE SUMMARY A 69-year-old male was admitted to our hospital with right upper quadrant pain for five days.Imaging suggested a liver mass with hemorrhage.A malignant hepatic tumor was the initial diagnosis.Surgical resection was performed after a complete preoperative work up.Initial postoperative pathology suggested that the mass was a malignant myoblastoma unrelated to the liver.Four months after the first surgery,an enhanced computed tomography(CT)scan revealed a recurrence of the tumor.The diagnosis of malignant myopericytoma derived from the colon was confirmed on histopathological examination of the specimen from the second surgery.The patient did not return to the hospital regularly for surveillance.The first postoperative abdominal CT examination six months after the second surgery demonstrated multiple liver metastases.Survival time between the diagnosis of the tumor to death was approximately one year.CONCLUSION Malignant myopericytoma is a rare cancer.Preoperative diagnosis may be difficult.Due to a lack of treatment options,prognosis is poor.

Colorectal cancer screening:The role of CT colonography

Computed tomography colonography(CTC) in colorectal cancer(CRC) screening has two roles:one present and the other potential.The present role is,without any further discussion,the integration into established screening programs as a replacement for barium enema in the case of incomplete colonoscopy.The potential role is the use of CTC as a first-line screening method together with Fecal Occult Blood Test,sigmoidoscopy and colonoscopy.However,despite the fact that CTC has been officially endorsed for CRC screening of average-risk individuals by different scientif ic societies including the American Cancer Society,the American College of Radiology,and the US Multisociety Task Force on Colorectal Cancer,other entities,such as the US Preventive Services Task Force,have considered the evidence insuff icient to justify its use as a mass screening method.Medicare has also recently denied reimbursement for CTC as a screening test.Nevertheless,multiple advantages exist for using CTC as a CRC screening test:high accuracy,full evaluation of the colon in virtually all patients,non-invasiveness,safety,patient comfort,detection of extracolonic findings and cost-effectiveness.The main potential drawback of a CTC screening is the exposure to ionizing radiation.However,this is not a major issue,since low-dose protocols are now routinely implemented,delivering a dose comparable or slightly superior to the annual radiation exposure of any individual.Indirect evidence exists that such a radiation exposure does not induce additional cancers.

Inhibitory effect of sulindac against chemically induced primary colonic tumours by N methyl N nitrosourea in mice

AIM To investigate the chemopreventive effect of sulindac, one of the nonstroidal anti inflammatory drugs (NSAIDs), on the growth of N methyl N nitrosourea (MNU) induced mouse colonic tumors.

Prevention of metastasis to liver by using 5-FU intraperitoneal chemotherapy in nude mice inoculated with human colonic cancer cells

AIMS Using a new approach of regional adjuvant chemotherapy to prevent cancer cells hepatic metasta- sis after radical surgery of large bowel cancer. METHODS A model of liver with metastasis of hu- man colonic cancer (HCC) cells in nude mice was used to observe the effect in prevention of metastasis of HCC cells inoculated via spleen applied with early postoper- ative intraperitoneal (IP) chemotherapy using large dose of 5-FU. RESULTS The incidence of metastasis to liver was decreased by 40%,the mean number of metastatic liv- er nodules in each animal was reduced by 50.89% and the mean survival times of each animal was prolonged by 48.21% by using 5-FU 40 mg/NS 40 ml/kg IP for two consecutive days as compared with the controls. CONCLUSIONS IP is a new and more effective re- gional adjuvant chemotheraputic approach in the pre- vention of liver metastasis HCC cells after radical surgery of large bowel cancer.

Incidence of colorectal neoplasms among male pilots

AIM: To assess the prevalence of colorectal neoplasms (adenomas, advanced adenomas and colorectal cancers) among Israeli military and commercial airline pilots.

Effects of ursolic acid and oleanolic acid on human colon carcinoma cell line HCT15

AIM: Ursolic acid (UA) and oleanolic acid (OA) are triperpene acids having a similar chemical structure and are distributed wildly in plants all over the world. In recent years, it was found that they had marked anti-tumor effects. There is little literature currently available regarding their effects on colon carcinoma cells. The present study was designed to investigate their inhibitory effects on human colon carcinoma cell line HCT15. METHODS: HCT15 cells were cultured with different drugs. The treated cells were stained with hematoxylin-eosin and their morphologic changes observed under a light microscope. The cytotoxicity of these drugs was evaluated by tetrazolium dye assay. Cell cycle analysis was performed by flow cytometry (FCM). Data were expressed as means +/-SEM and Analysis of variance and Student' t-test for individual comparisons. RESULTS: Twenty-four to 72 h after UA or OA 60 micromol/L treatment, the numbers of dead cells and cell fragments were increased and most cells were dead at the 72nd hour. The cytotoxicity of UA was stronger than that of OA. Seventy-eight hours after 30 micromol/L of UA or OA treatment, a number of cells were degenerated, but cell fragments were rarely seen. The IC(50) values for UA and OA were 30 and 60 micromol/L, respectively. Proliferation assay showed that proliferation of UA and OA-treated cells was slightly increased at 24h and significantly decreased at 48 h and 60 h, whereas untreated control cells maintained an exponential growth curve. Cell cycle analysis by FCM showed HCT15 cells treated with UA 30 and OA 60 for 36 h and 72 h gradually accumulated in G(0)/G(1) phase (both drugs P【0.05 for 72 h), with a concomitant decrease of cell populations in S phase (both drugs P【0.01 for 72 h) and no detectable apoptotic fraction. CONCLUSION: UA and OA have significant anti-tumor activity. The effect of UA is stronger than that of OA. The possible mechanism of action is that both drugs have an inhibitory effect on tumor cell proliferation through cell-cycle arrest.

Inhibitory effect of modified citrus pectin on liver metastases in a mouse colon cancer model

AIM: To discuss the expression of glactin-3 in liver metastasis of colon cancer and its inhibition by modi- fied citrus pectin (MCP) in mice. METHODS: Seventy-five Balb/c mice were randomly di- vided into negative control group (n = 15), positive con- trol group (n = 15), low MCP concentration group (n = 15), middle MCP concentration group (n = 15) and high MCP concentration group (n = 15). CT26 colon cancer cells were injected into the subcapsule of mouse spleen in positive control group, low, middle and high MCP concentrations groups, except in negative control, to set up a colon cancer liver metastasis model. The concen- tration of MCP in drinking water was 0.0%, 0.0%, 1.0%, 2.5% and 5.0% (wt/vol), respectively. Liver metastasis of colon cancer was observed after 3 wk. Enzyme-linked immunosorbent assay (ELISA) was used to detect the concentration of galectin-3 in serum. Expression of ga- lectin-3 in liver metastasis was detected by immunohis- tochemistry. RESULTS: Except for the negative group, the percent- age of liver metastasis in the other 4 groups was 100%, 80%, 73.3% and 60%, respectively. The number of liver metastases in high MCP concentration group was significantly less than that in positive control group (P = 0.008). Except for the negative group, the median volume of implanted spleen tumor in the other 4 groups was 1.51 cm3, 0.93 cm3, 0.77 cm3 and 0.70 cm3, respec- tively. The volume of implanted tumor in middle and high MCP concentration groups was significantly smaller than that in positive control group (P = 0.019; P = 0.003). The concentration of serum galectin-3 in positive control and MCP treatment groups was significantly higher than that in the negative control group. However, there was no significant difference between them. Except for the negative control group, the expression of galectin-3 in liver metastases of the other 4 groups showed no sig- nificant difference. CONCLUSION: Expression of galetin-3 increases sig- nificantly in liver metastasis of colon cancer, which can be effectively inhibited by MCP.

hOGG1 Ser326Cys polymorphism modifies the significance of the environmental risk factor for colon cancer

AIM:To determine the association of hOGG1 (8-oxoguanine glycosylase I,OGG1) polymorphism of Ser326Cys substitution with colon cancer risk and possible interaction with known environmental risk factors. METHODS:A case-control study with 125 colon cancer cases and 247 controls was conducted, RESULTS:There was no major difference in Ser326Cys genotype distribution between cases and controls.The meat intake tended to increase the odds ratio for colon cancer with an OR of 1.72 (95 % confidence interval;CI=1.12-2.76). Such tendency was more prominent in Cys/Cys carriers (OR=4.31,95 % CI=1.64-11.48),but meat intake was not a significant risk factor for colon cancer in Ser/Ser or Ser/ Cys carriers.The OR for colon cancer was elevated with marginal significance in smokers who were Cys/Cys carriers (OR=2.75,95 % CI=1.07-7.53) but not in Ser/Ser or Ser/ Cys carriers. CONCLUSION:These results suggest that the hOGG1 Ser326Cys polymorphism is probably not a major contributor to individual colon cancer susceptibility overall,but the Cys/ Cys genotype may alter the impact of some environmental factors on colon cancer development.

Colon cancer and the immune system:The role of tumor invading T cells

Colon cancer is still one of the leading causes of cancer death worldwide. Although the host immune system has been shown to react against tumor cells, mainly through tumor infi ltrating lymphocytes and NK cells, tumor cells may utilize different ways to escape anti-tumor immune response. Tumor infi ltration of CD8+ and CD4+ (T-bet+) effector T cells has been attributed to a beneficial outcome, and the enhancement of T cell activation through T cell receptor stimulation and co-stimulatory signals provides promising strategies for immunotherapy of colon cancer. Growing evidence supports a role for the Fas/FasL system in tumor immunology, although the mechanisms and consequences of FasL activation in colon cancer are not completely understood. In animal models, depletion of regulatory T cells (CD4+ CD25+ T cells) can enhance the anti-tumor immune response under certain conditions. Taken together, recent insights in the immune reaction against colon carcinoma have provided new approaches to immunotherapy, although much remains to be learned about the exact mechanisms.

Comparison of hydrocolonic sonograpy accuracy in preoperative staging between colon and rectal cancer

AIM:To compare the accuracy of hydrocolonic sonography (HUS) in determining the depth of invasion (T stage) in colon and rectal cancer. METHODS:A total of 1000-2000 mL of saline was instilled per rectum using a system for barium enemas,and then ultrasonography was conducted by a SSA-270A (Toshiba Co,Japan) sonolayer unit with a 3.75 MHz for 17 patients with colon cancer and 13 patients with rectal cancer before operation.After operation,T stage in HUS was compared with postoperative histological findings. RESULTS:Overall,the accuracy of T stage was 70%.It was 88% in colon cancer and 46% in rectal cancer.In evaluating nodal state,the accuracy of HUS was low in both colon (71%) and rectal cancers (46%) compared with conventional CT or MRI.The overall accuracy of N staging was 60%. CONCLUSION:HUS is valuable to evaluate the depth of invasion in colon cancer,but is less valuable in rectal cancer.Because HUS is low-cost,noninvasive,and readily available at any place,this technique seems to be useful to determine the preoperative staging in colon cancer,but not in rectal cancer.

Effects of endostatin on expression of vascular endothelial growth factor and its receptors and neovascularization in colonic carcinoma implanted in nude mice

AIM:To investigate the antiangiogenic effects of endostatin on colonic carcinoma cell line implanted in nude mice and its mechanism. METHODS:Nude mice underwent subcutaneous injection with LS-174t colonic carcinoma cell line to generate carcinoma and were randomly separated into two groups.Mice received injection of vehicle or endostatin every day for two weeks. After the tumor was harvested,the tumor volumes were determined,and the expressions of CD34,VEGF and FIk-1 were examined by immunohistochemical method. RESULTS:Tumor volume was significantly inhibited in the endostatin group(84.17%)and tumor weight was significantly inhibited in the endostatin group(0.197±0.049) compared to the control group(1.198±0.105)(F=22.56, P=0.001),microvessel density(MVD)was significantly decreased in the treated group(31.857±3.515)compared to the control group(100.143±4.290)(F=151.62,P<0.001). Furthermore,the expression of FIk-1 was significantly inhibited in the treated group(34.29%) ompared to the control group(8.57%)(X^2=13.745,P=0.001).However no significant decrease was observed in the expression of vascular endothelial growth factor(VEGF)between these two groups(X^2=0.119,P=0.730). CONCLUSION:Endostatin can inhibit tumor growth and angiogenesis by blocking Vegf/FIk-1 pathway.This experiment provides the theory basis for developing a new anti-carcinoma drug through studying the properties of anti-angiogenesis inhibitors.

Relationship between Fas/ FasL expression and apoptosis of colon adenocarcinoma cell lines

INTRODUCTIONFas/ FasL system has been identified as a keymediator of apoptosis in tumor cells[1-4]. Theoccurrence and development of neoplasm are closelyrelated to apoptosis[5-7] Most chemotherapeuticdrugs kill cancer cells mainly by inducingapoptosis[8-14].'

Polymorphism of thymidylate synthase gene associated with its protein expression in human colon cancer

AIM： To correlate the polymorphisms in the 5＇-untranslated region with thymidylate synthase （TS） protein expression in Han Chinese colonic neoplasms. METHODS： Adenocarcinoma samples were from 68 patients who received no treatment before surgery. Tandem repeat length of TS gene was determined by PCR amplification of genomic DNA. Intratumoral TS protein expression was studied immunohistochemically in corresponding sections from paraffin-embedded primary loci. Immunoreactivity was semiquantitatively evaluated by immunoreactivity score （IRS）. RESULTS： Double-（2R） and triple-repeated （3R） sequences of the TS gene were found in the cancer tissues. Three genotypes of TS were found： 2R/2R （n = 6）, 2R/3R （n = 22） and 3R/3R （n = 40）. Patients who were homozygous for triple-repeated （3R/3R） sequences showed significantly higher IRS of TS than patients who were homozygous for double-repeated （2R/2R） sequences or heterozygous patients （2R/3R）： 5.73 ±3.25 vs 2.17 ± 1.47 or 3.77 ±2.64, P = 0.008 or P = 0.015. But no statistical significance of IRS in cancer tissues was observed between 2R/3R genotype and 2R/2R genotype. CONCLUSION： There is a relationship between TS genotype and TS protein expression in clinical specimens. The data might offer an advantage for selection of Chinese cancer patients to receive fluoropyrimidines treatment.

Granular cell tumor of colon:Report of a case and review of literature

Granular cell tumor (GCT) is uncommon in the colon and rectum.Here we report a case of GCT in the transverse colon.A 48-year-old male patient underwent a screening colonoscopy.A yellowish sessile lesion,about 4 mm in diameter,was found in the transverse colon.An endoscopic snare resection was performed without complication. Histological examination revealed the tumor consisted of plump neoplastic cells with abundant granular eosinophilic cytoplasm containing acidophilic periodic acid Schiff- positive,diastase-resistant granules.Immunohistochemical analysis showed the tumor cells expressed S-100 protein and neuron-specific enolase.Thus,the resected tumor was diagnosed as a GCT.Since GCTs are usually benign,endoscopic resection constitutes an easy and safe treatment. Colonoscopists should consider the possibility of GCT in the differential diagnosis of submucosal tumors of the colon.

Definitive palliation for neoplastic colonic obstruction using enteral stents:Personal case-series with literature review

Acute colonic obstruction due to malignancies is an emergency that requires surgical treatment.Elderly patients or inoperable tumors require intestinal decompression that is a simple colostomy in almost all cases.This“manoeuvre” leads the patient to a percentage of moRality/morbidity and to a bad quality of life due to acceptance of stoma.The introduction of enteral metal stent inserted endoscopically has,in our opinion,provided a new way to obtaining the definitive palliation of inoperable colo-rectal cancer with a simple method.We reported our case-series and we analyzed the current literature and costs of treatments.

Ischemic colitis masquerading as colonic tumor:Case report with review of literature

Ischemic colitis can mimic a carcinoma on computed tomographic (CT) imaging or endoscopic examination. A coexisting colonic carcinoma or another potentially obstructing lesion has also been described in 20% of the cases of ischemic colitis. CT scan can differentiate it from colon cancer in 75% of cases. However, colonoscopy is the preferred method for diagnosing ischemic colitis as it allows for direct visualization with tissue sampling. Varied presentations of ischemic colitis have been described as an ulcerated or submucosal mass or as a narrowed segment of colon with ulcerated mucosa on colonoscopy. Awareness and early recognition of such varied presentations of a common condition is necessary to differentiate from a colonic carcinoma, and to avoid unnecessary surgery and related complications.

Malignant schwannoma of the pancreas involving transversal colon treated with en-bloc resection

Pancreatic schwannoma is a very uncommon tumor of the pancreas,with only 27 cases reported.Most pancreatic schwannomas are benign,with only four malignant tumors reported.We describe a case of giant malignant schwannoma of the pancreatic body and tail,which involved the transverse colon.The tumor was treated successfully with en bloc distal splenopancreatectomy and colon resection.This is believed to be the first reported radical operation for malignant schwannoma of the pancreatic body,with infiltration of the transverse colon,with excellent longterm results.The patient is alive and well 28 mo after the operation.The authors conclude that pancreatic schwannomas should be considered in the differential diagnosis of cystic neoplasms of the pancreas,although the diagnosis can only be confirmed by microscopic examination.In the case of the benign tumors,local excision is adequate,but in the case of malignant schwannoma,oncological standards must be fulfilled.

Primary early-stage intestinal and colonic non-Hodgkin's lymphoma: Clinical features, management, and outcome of 37 patients

AIM： To analyze the clinical features, management, and outcome of treatment of patients with primary intestinal and colonic non-Hodgkin＇s lymphoma （PICL）. METHODS： A retrospective study was performed in 37 patients with early-stage PICL who were treated in our hospital from 1958 to 1998. Their clinical features, management, and outcome were assessed. Prognostic factors for survival were analyzed by univariate analysis using the Kaplan-Meier product-limit method and log-rank test. RESULTS： Twenty-five patients presented with Ann Arbor stage Ⅰ PICL and 12 with Ann Arbor stage Ⅱ PICL. Thirty-five patients underwent surgery （including 31 with complete resection）, 22 received postoperative chemotherapy or radiotherapy or both. Two patients with rectal tumors underwent biopsy and chemotherapy with or without radiotherapy. The 5- and 10-year overall survival （OS） rates were 51.9% and 44.5%. The corresponding diseasefree survival （DIS） rates were 42.4% and 37.7%. In univariate analysis, multiple-modality treatment was associated with a better DFS rate compared to single treatment （P= 0.001）. While age, tumor size, tumor site, stage, histology, or extent of surgery were not associated with OS and DFS, use of adjuvant chemotherapy significantly improved DFS （P = 0.031） for the 31 patients who underwent complete resection. Additional radiotherapy combined with chemotherapy led to a longer survival than chemotherapy alone in six patients with gross residual disease after surgery or biopsy.CONCLUSION： Combined surgery and chemotherapy is recommended for treatment of patients with PICL, Additional radiotherapy is needed to improve the outcome of patients who have gross residual disease after surgery.

Effects of inositol hexaphosphate on proliferation of HT-29 human colon carcinoma cell line

AIM： To investigate the effects of inositol hexaphosphate （IP6） on proliferation of HT-29 human colon carcinoma cell line. METHODS： Cells were exposed to various concentrations （0, 1.8, 3.3, 5.0, 8.0, 13.0 mmol/L） of IP6 for a certain period of time. Its effect on growth of HT-29 cells was measured by MTT assay. The expressions of cell cycle regulators treated with IP6 for 2 d were detected by imrnunocytochemistry. RESULTS： IP6 inhibited the HT-29 cell growth in a dose- and time-dependent manner. Analysis of cell cycle regulator expression revealed that IP6 reduced the abnormal expression of P53 and PCNA and induced the expression of P21. CONCLUSION： IP6 has potent inhibitory effect on proliferation of HT-29 cells by modulating the expression of special cell cycle regulators.

Laterally spreading tumors:Limitations of computed tomography colonography

AIM: To prospectively investigate the detection rate of laterally spreading tumors (LSTs) of the colorectum by computed tomography (CT) colonography (CTC).