Biomedical subjects

K Geboes

Publications and source records attributed to K Geboes.

At least 73 records · Page 4Linked to original sources

PubMed2001

Vascular anatomy of the gastrointestinal tract.

The blood supply of the gastrointestinal system has intramural and extramural components. The intramural vascular distribution is generally well developed with plexuses in the different layers of the bowel wall and with specializations in the liver, small intestine and gastroesophageal junction, adapted to the function of these organs. The extramural arterial supply for the oesophagus is derived from the thoracic aorta or its major branches. Blood supply to the abdominal organs is provided by three major unpaired vessels arising from the abdominal aorta, namely the coeliac trunk and the superior and inferior mesenteric arteries. The branches of these vessels form anastomotic systems that provide a rich blood supply to the adjoining organs. In many areas the systems overlap while in other regions linkages are limited. Interrelations and weak points are of significant clinical importance. As well as this, there is a great individual variability in the anatomy of the gastrointestinal vasculature.

Angiography↗

PubMed2001

Intravenous cyclosporine versus intravenous corticosteroids as single therapy for severe attacks of ulcerative colitis.

BACKGROUND & AIMS: Cyclosporine has been effective in patients with steroid-refractory attacks of ulcerative colitis (UC). We investigated the effects of intravenous (IV) cyclosporine as single IV therapy (without glucocorticosteroids) for severe UC and compared these with the response to glucocorticosteroids. METHODS: Patients with a severe attack of UC were randomized to treatment with IV cyclosporine, 4 mg x kg(-1) x day(-1), or with methylprednisolone, 40 mg/day, in a randomized, double-blind, controlled trial. After 8 days, patients who had a response received the same medication orally in combination with azathioprine. Patients were followed up clinically, endoscopically, and by scintigraphy. Renal function was assessed using urinary inulin clearances. Endpoints were clinical improvement, discharge from the hospital, and remission up to 12 months after intravenous therapy. RESULTS: Thirty patients were included. After 8 days, 8 of 15 patients (53%) who received methylprednisolone had a response to therapy vs. 9 of 14 (64%) receiving cyclosporine. In nonresponders, 3 of 7 methylprednisolone patients and 1 of 3 cyclosporine patients improved when both treatments were combined. No serious drug-related toxicity was observed with either treatment. At 12 months, 7 of 9 patients (78%) initially controlled with cyclosporine maintained their remission vs. 3 of 8 (37%) initially treated with methylprednisolone. No clinically significant decrease of renal function was observed. CONCLUSIONS: Cyclosporine monotherapy is an effective and safe alternative to glucocorticosteroids in patients with severe attacks of UC.

Adult↗

PubMed2001

Understanding inflammatory bowel disease--the clinician's perspective.

The treatment of patients with ulcerative colitis and Crohn's disease is a huge challenge to the clinician mainly because the etiology of IBD is still completely unknown. Pathogenetic mechanisms, in constrast, have partly been elucidated thanks to immunohistochemical investigation of the tissue in IBD and the study of experimental animal models of gut inflammation. There is extensive evidence that at least in Crohn's disease tolerance for commensal bacteria is lost which leads to uncontrolled inflammation mediated by a T-helper 1 response and to tissue destruction of the gut epithelium with inadequate repair. Genetic factors are probably responsible for increased susceptibility and may define disease phenotypes. These insights have led to a dramatic improvement of our therapeutic means with the development of the chimeric monoclonal antibody to TNF. The pathogenetic mechanisms are less clear in UC. The hypothesis is that UC is a T-helper 2 mediated disease. We have a very attractive way to study the early onset of Crohn's disease in the postoperative Crohn's situation. Newer therapeutic approaches should aim at preventing recurrence of Crohn's lesions in the normal postoperative bowel. Such model is also available for UC since there is increasing evidence that pouchitis is recurrent ulcerative colitis in the small bowel. Cooperation between clinicians and basic scientists is the best way to achieve fast progress in understanding IBD.

Humans↗

PubMed2001

Etanercept in the treatment of active refractory Crohn's disease: a single-center pilot trial.

OBJECTIVES: Etanercept, an injectable tumor necrosis factor (TNF) receptor fusion protein, binds and inactivates human TNF and is used in active rheumatoid arthritis. Blocking TNF with monoclonal antibodies has also been beneficial in Crohn's disease. We attempted to determine the efficacy and safety of etanercept for induction of clinical, endoscopic, and histological improvement in patients with moderate to severe Crohn's disease despite standard treatment. METHODS: Ten patients with active Crohn's disease were treated with etanercept (25 mg s.c.) twice per week for 12 wk. Background therapy was kept stable during the trial. Crohn's disease activity index (CDAI), Inflammatory Bowel Disease Questionnaire, and C-reactive protein levels were measured at weeks 0, 2, 4, 8, and 12. Colonoscopies were performed before and after therapy in responders; endoscopic biopsies were scored for inflammation. RESULTS: At week 2 after the start, a clinical response (deltaCDAI > or = 70) was observed in 6/10 patients (median = 305 [294-418] to 166 [107-392]), with reduction in serum C-reactive protein levels (median = 17.2 [6.8-67.2] to 9.1 [0.9-17.2] mg/dl). Colonoscopies showed a reduction in inflammatory lesions in the four patients who attained remission (CDAI < 150), whereas the inflammatory score of the biopsies did not decrease significantly. No moderate or severe adverse events were observed. CONCLUSIONS: Etanercept may be effective in Crohn's disease refractory to standard therapy.

Adolescent↗

PubMed2001

Expression of chemokine receptors in vernal keratoconjunctivitis.

BACKGROUND/AIMS: Chemokines are small peptides which are potent activators and chemoattractants for leucocyte subpopulations. Their action is mediated by a family of seven transmembrane spanning G-protein coupled receptors. The aims of this study were to examine the expression of the chemokine receptors CCR1, CCR3, CCR5, CXCR3, and CXCR4 in the conjunctiva of patients with vernal keratoconjunctivitis (VKC) and to investigate the phenotype of inflammatory cells expressing these chemokine receptors. METHODS: Conjunctival biopsy specimens from 16 patients with active VKC, and eight control subjects were studied by immunohistochemical techniques using a panel of monoclonal antibodies directed against human CCR1, CCR3, CCR5, CXCR3, and CXCR4. The phenotype of inflammatory cells expressing chemokine receptors was examined by double immunohistochemistry. RESULTS: In the normal conjunctiva, few inflammatory cells expressed CXCR3 in five of eight specimens. There was no immunoreactivity for CCR1, CCR3, CCR5, and CXCR4. In VKC specimens, membranous immunoreactivity for CXCR3 was noted on inflammatory cells in all specimens. Compared with control specimens, VKC specimens showed significantly more inflammatory cells expressing CXCR3 (54.3 (SD 34.3) v 3.3 (5.0); p<0.001). Few CCR1+, CCR3+, CCR5+, and CXCR4+ inflammatory cells were observed in only three of 16 specimens. Double immunohistochemistry revealed that all CXCR3 positive inflammatory cells were CD3 positive T lymphocytes and that 61.7% (3.7%) of the infiltrating T lymphocytes were reactive for CXCR3. CONCLUSIONS: CXCR3 is the predominant chemokine receptor and is expressed abundantly on T lymphocytes in the conjunctiva of patients with active VKC. These data suggest a potential role for CXCR3 receptors in the regulation of lymphocyte recruitment within conjunctiva of VKC patients. New therapeutic strategies that block CXCR3 may inhibit T lymphocyte recruitment and suppress adverse inflammatory reactions.

Adolescent↗

PubMed2001

Interleukin 10 (Tenovil) in the prevention of postoperative recurrence of Crohn's disease.

BACKGROUND AND AIMS: New lesions of Crohn's disease occur early after ileal or ileocolonic resection and ileocolonic anastomosis. We performed a double blind controlled trial to evaluate the safety and tolerance of recombinant human interleukin 10 (IL-10; Tenovil) in subjects operated on for Crohn's disease. We also assessed the effect of Tenovil in preventing endoscopic recurrence 12 weeks after surgery. METHODS: Patients with Crohn's disease who underwent curative ileal or ileocolonic resection and primary anastomosis were randomised within two weeks after surgery to receive subcutaneous Tenovil 4 microg/kg once daily (QD) (n=22) or 8 microg/kg twice weekly (TIW) (n=21), or placebo (QD or TIW) (n=22). An ileocolonoscopy was performed after 12 weeks of treatment. RESULTS: Compliance was excellent. The most frequently observed adverse events were mild and moderate in severity and equally distributed across treatment groups. Thirty seven patients in the pooled Tenovil group and 21 patients in the pooled placebo group were evaluable by endoscopy. At 12 weeks, 11 of 21 patients (52%) in the placebo group had recurrent lesions compared with 17 of 37 patients (46%) in the Tenovil group (ns). The incidence of severe endoscopic recurrence was similar in both groups (9%). CONCLUSION: Tenovil treatment for 12 consecutive weeks in patients with Crohn's disease after intestinal resection was safe and well tolerated. No evidence of prevention of endoscopic recurrence of Crohn's disease by Tenovil was observed.

Adult↗

PubMed2001

Tenascin and strictures in inflammatory bowel disease: an immunohistochemical study.

Tenascin is an extracellular matrix protein involved in morphogenesis of muscle tissue and in wound healing. In the present study we examined its distribution in tissue from patients with inflammatory bowel disease. Intestinal biopsies from 10 normal controls, 15 patients with Crohn's disease, and 6 with ulcerative colitis were studied. Samples were obtained both from uninvolved and involved areas. Mucosal tenascin is increased in ulcerative colitis and Crohn's disease, especially in areas of ulceration. In Crohn's disease, tenascin is also strongly expressed in the submucosa and in smooth muscle cells of the muscularis mucosae and propria, especially in areas of stricture. We conclude that tenascin is involved in stricture formation in Crohn's disease and that it is a marker of phenotypic change in smooth muscle cells.

Adult↗

PubMed2001

Immunology of trachomatous conjunctivitis.

Trachoma, a chronic follicular conjunctivitis caused by infection with Chlamydia trachomatis, is a leading cause of preventable blindness. The blinding complications are associated with progressive conjunctival scarring. Our immunohistochemical studies of conjunctival biopsies from children with active trachoma demonstrated the presence of both humoral and cell-mediated immune responses. Antichlamydial antibodies can neutralize Chlamydiae, block attachment and internalization of the organism, and can produce partial immunity. Our observations suggest a role for T-lymphocytes and cell mediated immunity in the genesis of conjunctival scarring. Conjunctival epithelial cells expressed major histocompatibility complex (MHC) class II antigens which might allow conjunctival epithelial cells to present Chlamydial antigens to T-cells enhancing the immune response. The epithelial cells expressing MHC class II antigens might present autoantigens to T-cells leading to induction of an autoimmune reaction. We have demonstrated that the conjunctival epithelial cells from patients with trachoma expressed interleukin (IL)-1 alpha and IL-1 beta. In addition, we have detected cytoplasmic expression of IL-1 alpha, IL-1 beta, tumor necrosis factor alpha and platelet-derived growth factor by macrophages. These cytokines have the potential to influence the remodeling and fibrosis observed in trachoma. Alterations of extracellular matrix components and collagen metabolism occur in the conjunctival tissue from patients with trachoma. New collagen type V formation was noted in active trachoma and scarred trachoma. The conjunctival tissue from patients with active trachoma contained increased amounts of collagen types I, III and IV. Scarred trachoma is characterized by marked increase in basement membrane--collagen IV and marked decrease in collagen types I and III. In addition, we demonstrated increased activity of gelatinase B and numbers of inflammatory cells containing gelatinase B in trachoma patients suggesting that this enzyme might be involved in matrix degradation and promotion of conjunctival scarring in trachoma.

Animals↗

PubMed2001

Biological therapies in IBD: an international course.

Crohn's disease and ulcerative colitis, both chronic inflammatory bowel diseases, have become an important health problem in the US and in Northern Europe. Both diseases require significant medical therapy for treatment and prevention of relapses. Traditional treatment is based on aminosalicylates and steroids. Steroids are associated with major complications and many patients are either dependent upon or refractory to steroids. The development of new drugs is therefore very important. This is possible because of a better knowledge of the pathogenetic mechanisms of the diseases. Many of the new drugs belong to the family of biologic therapies. Because of the expense of production and the parenteral delivery systems needed for most of them, these therapies must prove to be significantly more effective than traditional drugs. Many biologic agents are still under investigation. Therapeutic strategies directed against tumor necrosis factor (TNF)-alpha, including monoclonal antibodies, such as infliximab and CDP-571 and the human recombinant TNF receptor fusion protein, etanercept, have already been proven to be beneficial, especially in treating Crohn's disease. Treatment with infliximab induces even endoscopic and histologic healing. The benefit of additional immunosuppressive therapy is under investigation. New treatment strategies that might change the natural course of the disease can be considered for Crohn's disease. The experience with biologic agents for ulcerative colitis is still limited. A preliminary study with antegren, a recombinant humanized antibody against integrins is promising. The initial safety experience with infliximab is favorable but, ultimately, evaluation of large populations of patients over many years is required to define the relative safety of biologic agents.

Journal Article↗

PubMed2001

Colitis cystica profunda.

A 39-year-old woman with inflammatory bowel disease was admitted to the hospital because of cramping abdominal pain and diarrhea. Ultrasound of the abdomen revealed thickening of the wall of the descending colon. At endoscopy mucosa-covered nodules with substenosis were seen. A double-contrast examination showed narrowing in the transition zone between the descending colon and sigmoid with mucosal nodularities and barium spots in between. Examination of the resection specimen revealed colitis cystica profunda. After surgical treatment the history of the patient was uneventful.

Adult↗

PubMed2000

Prevention of experimental colitis in SCID mice reconstituted with CD45RBhigh CD4+ T cells by blocking the CD40-CD154 interactions.

Increased expression of CD40 and CD40 ligand (CD40L or CD154) has been found in inflamed mucosa of human inflammatory bowel disease (IBD), and interactions between these molecules seem to be involved in local cytokine production by macrophages. However, the precise role of CD40 signaling in the pathogenesis of IBD is still poorly understood. The aim of the present study was to investigate the in vivo relevance of CD40 signaling in experimental colitis in SCID mice reconstituted with syngeneic CD45RBhighCD4+ T cells. The results demonstrated that CD40+ and CD40L+ cells as well as their mRNA levels were significantly increased in inflamed mucosa. Administration of anti-CD40L neutralizing mAb over an 8-wk period starting immediately after CD45RBhighCD4+ T cell reconstitution completely prevented symptoms of wasting disease. Intestinal mucosal inflammation was effectively prevented, as revealed by abrogated leukocyte infiltration and decreased CD54 expression and strongly diminished mRNA levels of the proinflammatory cytokines IFN-gamma, TNF, and IL-12. When colitic SCID mice were treated with anti-CD40L starting at 5 wk after T cell transfer up to 8 wk, this delayed treatment still led to significant clinical and histological improvement and down-regulated proinflammatory cytokine secretion. These data suggest that the CD40-CD40L interactions are essential for the Th1 inflammatory responses in the bowel in this experimental model of colitis. Blockade of CD40 signaling may be beneficial to human IBD.

Animals↗

PubMed2000

IL-15 is highly expressed in inflammatory bowel disease and regulates local T cell-dependent cytokine production.

IL-15 shares biological activities but no significant sequence homology with IL-2. It induces T cell recruitment to sites of inflammation, T cell proliferation, and cytokine production and rescue from apoptosis. The aim of this study was to investigate expression of IL-15 and its effects on proinflammatory cytokine production in inflammatory bowel disease (IBD). Immunohistochemistry demonstrated local IL-15 production by macrophages in inflamed mucosa from IBD patients. Isolated lamina propria mononuclear cells from these patients but not from controls produced IL-15 when stimulated with LPS or IFN-gamma. Moreover, lamina propria T cells (LP-T) from IBD patients were more responsive to IL-15 as compared with controls, and IL-15 alone without a primary T cell stimulus induced IFN-gamma and TNF production by isolated IBD LP-T cells, especially by LP-T cells from patients with Crohn's disease. LP-T cells from IBD patients could induce CD40-CD40 ligand (CD40L) interaction-dependent TNF and IL-12 production by monocytes in a coculture system. This capacity of LP-T cells was strongly enhanced by preincubation in IL-15 and was the result of higher CD40L expression after culture in IL-15. These data indicate that IL-15 is overexpressed in the inflamed mucosa in IBD and that IL-15 enhances local T cell activation, proliferation, and proinflammatory cytokine production by both T cells and macrophages, the latter via a CD40-CD40L interaction-dependent mechanism. Treatment directed against IL-15 may have therapeutic potential in IBD.

Adult↗

PubMed2000

Limitations of peritoneal lavage with antiseptics in prevention of recurrent colorectal cancer caused by tumor-cell seeding: experimental study in rats.

PURPOSE: Exfoliated or soiled free malignant cells have serious consequences in patients undergoing gastrointestinal cancer surgery. The present study evaluates the toxicity and efficacy of cytotoxic agents in the prevention of cell seeding and tumor growth in the peritoneal cavity in an experimental model. METHODS: Mtln3 adenocarcinoma cell viability was tested in vitro using the trypan blue exclusion test after incubation with povidone-iodine or chlorhexidine. In vivo, Fischer rats were inoculated with 10(5) or 10(6) cells followed by peritoneal lavage with physiological saline, chlorhexidine 0.02 percent, povidone-iodine low molecular weight 1 percent or povidone-iodine high molecular weight 1 and 2 percent in different quantities and incubation times. RESULTS: Chlorhexidine 0.02 percent and povidone-iodine low molecular weight 1 percent or high molecular weight 2 percent, killed over 98 percent of 10(5) or 10(6) tumor cells in vitro. Povidone-iodine low molecular weight 1 percent and high molecular weight 2 percent were toxic and lethal when 5 ml were applied in the peritoneal cavity three times for five minutes. Chlorhexidine 0.02 percent applied after inoculation of 10(5) or 10(6) cells, reduced the tumor development only to 70 and 80 percent. Application of 5 ml povidone-iodine 1 percent low molecular weight or high molecular weight, three times for one and five minutes, after inoculation of 10(6) cells did not change the tumor take. However, inhibition of Mtln3 cells to form metastases was observed. When povidone-iodine low molecular weight 1 percent was used three times for one minute after 10(5) tumor cells were "soiled", no toxicity was observed and the tumor take was reduced to 30 percent (P < 0.05). CONCLUSIONS: Povidone-iodine toxicity proved to be a major issue in vivo. However, povidone-iodine low molecular weight 1 percent was safe when used for short periods and very effective when a limited number of tumor cells was inoculated. The use of cytotoxic agents to prevent recurrent disease caused by tumor cell seeding in patients seems to make sense only when the "inoculum size" of exfoliated or soiled cancer cells is limited.

Adenocarcinoma↗

PubMed2000

Multifocal epithelioid angiosarcoma of the small intestine.

A 67-year-old man presented with weight loss, intermittent severe abdominal pain and melaena. Initial radiology (including abdominal ultrasonography), gastroscopy and colonoscopy did not demonstrate any lesions that could explain the complaints. Three weeks later, upper gastrointestinal and small-bowel barium studies revealed two areas in the small intestine with an abnormal mucosal pattern. Explorative laparotomy revealed three tumoral lesions. Three partial enterectomies were performed. Gross examination showed centrally depressed dark reddish tumoral lesions extending from the mucosa throughout the full thickness of the bowel wall (diameter varying between 1.6 cm and 2.2 cm). The tumours, composed of large, plump, polygonal cells showing little architectural differentiation, were mainly situated in submucosa and muscularis propria. The growth pattern appeared rather solid. The epithelioid cells showed pronounced nuclear pleomorphism and atypia with central large nucleoli. There were several small blood vessels with occasional anaplastic endothelial cells. Immunohistochemical staining demonstrated an intense expression of CD 31, CD 34, factor VIII related antigen and keratin. This supported the diagnosis of an epithelioid angiosarcoma. The patient died 3 months after diagnosis. Tumours of the small intestine are very rare, and angiosarcomas of the small intestine are even more rare. Epithelioid variants have only been described in two patients and only one of these had a multifocal presentation. The prognosis is very poor. Because of the epithelioid growth pattern and the cytokeratin expression, these tumours may erroneously be diagnosed as a carcinoma.

Abdominal Pain↗

PubMed2000

The product of the t(11;18), an API2-MLT fusion, marks nearly half of gastric MALT type lymphomas without large cell proliferation.

Recently we demonstrated that the t(11;18)(q21;q21) associated with extranodal marginal zone B cell lymphomas of MALT type results in the expression of a chimeric transcript fusing 5' API2 on chromosome 11 to 3' MLT on chromosome 18. Here we report the development of an RT-PCR approach for the detection of the API2-MLT fusion transcript and its application for the analysis of 58 cases of gastric lymphoma. Initially nested PCR amplification was combined with Southern analysis using internal API2 and MLT probes. A genuine API2-MLT fusion transcript of variable length was demonstrated in 11 out of 58 cases. Sequence analysis revealed that in all cases the breakpoint on chromosome 11 occurred between exons 7 and 8 of the API2 gene. In contrast, the breakpoints on chromosome 18 appeared to be heterogeneous as fusions to bp 814, 1123, and 1150, respectively, of MLT were observed. These observations allowed us to work out a highly sensitive diagnostic test for the API2-MLT fusion on an ABI Prism 7700 sequence detector that confirmed the results of our initial approach. The API2-MLT fusion was found in 48% of gastric marginal zone cell lymphomas of MALT type that did not contain a large cell component and it was lacking in all other lymphomas of the stomach.

Caspases↗

PubMed2000

Diffusion limited hypoxia estimated by vascular image analysis: comparison with pimonidazole staining in human tumors.

PURPOSE: To assess diffusion limited hypoxia in human tumors using image analysis of vasculature and to compare it with the bioreductive marker pimonidazole as an independent method. MATERIALS AND METHODS: To set up the method, nine rectal adenocarcinomas and ten squamous cell carcinomas were analyzed. To validate the method, ten squamous cell carcinomas of the cervix were analyzed from patients who were injected with pimonidazole and biopsied approximately 24 h later. Sections of the rectal and esophageal tumors were stained for vasculature, while cervix tumor sections were double stained for vasculature and pimonidazole. Tumor areas were delineated on digitized images, and the proportion of tumor tissue greater than a fixed distance from the nearest blood vessel (called diffusion limited fraction, DLF) was then calculated. The proportion of tumor area stained for pimonidazole was also measured. RESULTS: There was a wide variation between tumors in both the vascular-derived DLF and in the pimonidazole-stained fraction. Average DLFs varied between 1.5 and 92% for different tumors, with significant differences between them. The area stained by pimonidazole was significantly smaller than DLF for all tumors. The correlation between pimonidazole area and DLF was significant in three of seven tumors containing > or = 3 images. When images from all tumors (n=123) were analyzed together, the correlation was highly significant (r=0.47, P<0.0001). CONCLUSION: The vascular derived DLF correlates significantly with pimonidazole staining, but there was large scatter. Both methods may underestimate perfusion limited hypoxia.

Adenocarcinoma↗

PubMed2000

Enhanced production of IL-8 in chronic but not in early ileal lesions of Crohn's disease (CD).

Distinct Th1/Th2 patterns have been observed during the evolution of CD. The aim of this study was to compare neutrophil involvement and IL-8 mRNA and protein expression during early recurrent lesions and chronic phases of CD. Twenty-nine patients with CD having ileocolonic resection with anastomosis were studied. Biopsies were obtained during surgery from the non-inflamed ileal mucosa and from chronic ileal lesions. Endoscopic ileal biopsies were also taken from early recurrent ileal lesions occurring 3 months after surgery. Neutrophil counts were performed and mucosal IL-8 levels were evaluated by competitive reverse transcriptase-polymerase chain reaction and immunohistochemistry. Early recurrent ileal lesions were characterized by low neutrophil counts and IL-8 production at the mRNA and protein levels compared with the ileal chronic lesions. The main cellular sources of IL-8 in the early recurrent lesions were neutrophils, while in chronic lesions the majority of IL-8-stained cells were CD3+ T cells and macrophages. These results confirmed that the nature of the inflammatory infiltrate and the expression of cytokine profiles may differ between the acute and chronic phases of CD.

Adult↗

PubMed2000

The diagnosis of dysplasia and malignancy in Barrett's oesophagus.

Barrett's metaplasia is associated with an increased risk for adenocarcinoma. Adenocarcinoma develops through a multistep process characterized by defects in genes and morphological abnormalities. The early morphological changes of the process are called 'dysplasia'. Dysplasia is defined as an unequivocal neoplastic (premalignant) transformation confined within the basement membrane. For most Western pathologists malignancy is defined as invasion and characterized by a breach through the basement membrane. Japanese pathologists rely on cytological atypia and complex branching of crypts. Cytological and architectural abnormalities allow identification of dysplasia on routinely stained sections. A distinction is made between low- and high-grade dysplasia. The differential diagnosis between low-grade dysplasia and reactive changes can be difficult. Therefore a second opinion is strongly recommended, not only for high-grade dysplasia but also for low-grade. Immunohistochemistry for p53 and flow cytometry for detection of aneuploidy can support the diagnosis. Identification of dysplasia and malignancy depends on the number of biopsy samples examined. The minimum number of biopsies required has not yet been determined and depends partly on the length of the metaplastic segment. It has been proposed to sample with four quadrant biopsies at 20-mm intervals. New endoscopic techniques can increase the diagnostic yield. Endoscopically visible lesions increase the risk of finding malignancy. The time sequence for the progression of dysplasia is not known but progression from low- to high-grade and cancer has been shown to occur over a period of years although it may not be inevitable.

Adenocarcinoma↗