High galectin expression in Helicobacter pylori-infected gastric mucosa in childhood.

BACKGROUND: Mild Th1 and Th17 immune responses in childhood against Helicobacter pylori are presumed to be responsible for H. pylori colonization and mucosal atrophy reduction. However, the mechanism remains unclear. In this study, we aimed to investigate the childhood-specific immune responses observed after H. pylori infection by analyzing galectin expression in the gastric mucosa. We focused on galectin-1 (Gal-1) and galectin-9 (Gal-9), which function to suppress Th1 and Th17 immune responses. METHODS: We analyzed changes in the expression of Gal-1 and Gal-9 in the gastric mucosa of pediatric patients with H. pylori infection. Ten pediatric patients with and ten patients without H. pylori infection who underwent biopsy to assess the cause of chronic abdominal symptoms using esophagogastroduodenoscopy were evaluated. Gal-1 and Gal-9 expression in the biopsy tissues of the gastric antrum and corpus was analyzed by immunohistochemical staining. RESULTS: Gal-1 expression was significantly increased in the stromal cells of the corpus owing to H. pylori infection. No alterations in Gal-1 expression due to H. pylori infection were observed in the antral tissue. Helicobacter pylori infection considerably increased Gal-9 expression in all tissues. According to previous reports, the increased expression of Gal-9 associated with H. pylori infection is not observed in adults. Therefore, the increased expression of Gal-9 associated with H. pylori infection is specific to pediatric patients. CONCLUSION: The increased expression of Gal-1 and Gal-9 may suppress Th1 and Th17 immune responses against H. pylori infection during childhood, promote H. pylori colonization, and reduce inflammation in the gastric mucosa of pediatric patients.

Modulation of Intestinal Motility in an Adolescent Rat Model of Irritable Bowel Syndrome.

INTRODUCTION: The pathophysiology of irritable bowel syndrome (IBS) remains unknown. This study aimed to evaluate colonic motility and serotonin system response to restraint stress (RS) among adolescent rats who underwent neonatal maternal separation (NMS) to clarify the features of pathogenesis in adolescents with IBS. METHODS: Male rats were exposed to NMS as chronic stress, and a normally handled (NH) group was used as control. Four groups were created by adding RS as acute stress treatment to the NMS and NH groups. To realize the RS treatment, the subjects were restrained for 1 h at the age of 5 weeks, and hourly fecal pellet discharge was determined. After euthanization and proximal colon intestinal tissue collection, 5-hydroxytryptamine (5-HT) and 5-hydroxytryptamine receptor 3 (5-HT3R) concentrations, enterochromaffin (EC) cell density, and the expression of mRNA-encoding slc6a4 were examined. RESULTS: The amount of fecal pellet discharge during RS increased significantly in the RS and NMS+RS groups compared with that in the NH and NMS groups, respectively. The 5-HT concentration in the intestinal tissue of rats in the RS and NMS groups increased significantly compared with that of rats in the NH group. EC cell density also increased significantly in the NMS and NMS+RS groups compared with that in the NH and RS groups. However, combined stress did not result in any significant differences in the expression of 5-HT3R and mRNA-encoding slc6a4. CONCLUSIONS: The combination of juvenile and acute stress effectively induced increased 5-HT concentration or EC cell density via the 5-HT pathway in the proximal colon of adolescent rats.

Differentiation of Active Ulcerative Colitis vs Noninflammatory Bowel Disease Proctitis by Transperineal Superb Microvascular Imaging.

BACKGROUND: Transabdominal ultrasonography and transperineal ultrasonography (TPUS) appear correspond to colonoscopy (CS) for evaluating ulcerative colitis (UC) activity, but their utility in UC diagnosis remains unclear. This research compared the accuracy of TPUS and CS for assessing rectal activity and differentiating noninflammatory bowel disease proctitis from UC in pediatric cases. METHODS: The study is a blinded, prospective, and controlled trial. Prospectively, values of fecal calprotectin (FCP) and findings of the TPUS and CS were compared between child cases of UC and non-IBD proctitis. Findings of rectal wall thickening (RWT), rectal wall flow (RWF) on power Doppler, and microvascular signal at wall circumference (MSWC) on monochrome superb microvascular imaging assessed using TPUS were compared with the CS. RESULTS: Thirty patients with Mayo endoscopic subscore (MES) 0 to 1 UC, 57 with MES 2 to 3 UC, and 44 with proctitis were registered. Fecal calprotectin, RWF, and MSWC indicated significant differences among the groups (P < .05). Rectal wall thickening showed no significant difference between MES 0-1 and proctitis (P = .76). Rectal wall thickening and MSWC were independent predictors of endoscopic activity of UC, resulting in a sensitivity and specificity of 100% for RWT ≥4.5 mm and positive MSWC. Fecal calprotectin and RWF were independent predictors for differentiating MES 0 to 1 and proctitis, and FCP and RWT were independent predictors for differentiating MES 2 to 3 and proctitis. Sensitivity and specificity were 77.2% and 80.9%, respectively, for FCP >242.5 µg/g and RWF negative; and they were both 100% for RWT >4.1 mm and MSWC positive. CONCLUSIONS: Transperineal ultrasonography with mSMI may enable the evaluation of rectal activity and differentiation of UC from non-IBD proctitis with accuracy comparable to endoscopy.

Transperineal ultrasonography with superb microvascular imaging can differentiate ulcerative colitis from noninflammatory bowel disease proctitis and is therefore useful in distinguishing whether diarrhea and bloody stool during the treatments of ulcerative colitis are due to recurrence or infection.

Eosinophilic enteritis requiring differentiation from chronic enteropathy associated with SLCO2A1 gene: A case report.

BACKGROUND: Eosinophilic gastrointestinal disease (EGID) is a disorder characterized by infiltration of eosinophils causing mucosal damage and dysfunction of the gastrointestinal tract. The endoscopic findings of eosinophilic enteritis (EoN), an EGID variant, are nonspecific and occasionally difficult to diagnose. In contrast, chronic enteropathy associated with SLCO2A1 (CEAS) is a chronic persistent small intestinal disorder characterized by endoscopic findings such as multiple oblique and circular ulcers. CASE SUMMARY: We report the case of a 10-year-old boy who had suffered abdominal pain and fatigue for the preceding 6 mo. He was referred to our institute for investigation of suspected gastrointestinal bleeding because of severe anemia with hypoproteinemia and positive fecal human hemoglobin. The upper and lower gastrointestinal endoscopic findings were normal; however, double-balloon small bowel endoscopy showed multiple oblique and circular ulcers with discrete margins and mild constriction of the intestinal lumen in the ileum. The findings were highly consistent with CEAS, but urine prostaglandin metabolites were within normal limits, and no previously reported mutations in the SLCO2A1 gene were identified. Histological evaluation demonstrated moderate to severe eosinophilic infiltration localized to the small intestine suggesting a diagnosis of EoN. Clinical remission was maintained with montelukast and a partial elemental diet, but emergent surgery for bowel obstruction due to small intestinal stenosis was performed two years after the initial treatment. CONCLUSION: EoN should be considered in the differential diagnosis of CEAS-like small intestinal ulcerative lesions and normal urinary prostaglandin metabolite levels.

Accuracy of Transperineal Ultrasonography for Assessing Rectal Lesions in Paediatric Ulcerative Colitis: A Prospective Study.

BACKGROUND AND AIMS: Transabdominal ultrasonography [TAUS] appears comparable to colonoscopy for evaluating ulcerative colitis [UC] activity, but it has low accuracy in rectal evaluation. In this study, the accuracy of transperineal ultrasonography [TPUS] for evaluating rectal activity was compared to that of colonoscopy in paediatric UC cases. METHODS: Faecal calprotectin [FCP] values and TPUS and colonoscopic findings were compared prospectively in paediatric UC cases. Rectal wall thickening [RWT] and rectal wall flow [RWF] on power Doppler evaluated by TPUS were compared with the colonoscopy findings and were also measured on TAUS and assessed for the concordance rate of each finding. RESULTS: Thirty Mayo endoscopic sub-score [MES] 0-1 UC cases and 57 MES 2-3 UC cases were enrolled. FCP, RWT and RWF showed significant differences between the two groups [p < 0.05]. RWT and RWF were independent predictors of UC endoscopic activity, showing sensitivity of 95.8% and specificity of 100% with RWT ≥ 4.5 mm and positive RWF. The concordance rates between TPUS and TAUS findings in MES 2-3 were moderate to fair, whereas those in MES 0-1 were fair to poor. The concordance rates between ultrasonic examiners were good for both TAUS and TPUS. CONCLUSIONS: TPUS may evaluate rectal activity of UC with accuracy comparable to endoscopy. If accurate ultrasonic screening for the total colon can be performed by TPUS and TAUS, repeated evaluation of short-term treatment response may be possible.

An Isolated Intestinal Juvenile Polyp Diagnosed by Abdominal Ultrasonography and Resected by Double-Balloon Endoscopy: A Case Report and Literature Review.

Juvenile polyps, typically localized in the rectum and sigmoid colon, are a common cause of pediatric bloody stool. An isolated small intestinal juvenile polyp is uncommon and generally difficult to diagnose. The first case of an isolated juvenile polyp diagnosed by abdominal ultrasonography before acute abdomen had developed and resected by double-balloon endoscopy is presented along with a review of previous reports including this case. A two-year-old Japanese boy was referred to our institute for further evaluation of anemia persisting from one year of age. Laboratory findings showed mild iron deficiency anemia and elevated fecal human hemoglobin (Hb) and fecal calprotectin values. Upper and lower endoscopic findings showed no abnormalities. Because the abdominal ultrasonography performed one year later demonstrated a 15 mm jejunal polyp, combined with a similar finding on small intestinal capsule endoscopy, this was diagnosed as an isolated lesion. The lesion was resected by cautery with double-balloon endoscopy and diagnosed as a juvenile polyp pathologically. All clinical symptoms disappeared, and all laboratory data improved after treatment, without recurrence for more than one year after the procedure. Abdominal ultrasonographic screening and the fecal calprotectin value led to the diagnosis and non-surgical invasive treatment of an isolated small intestinal juvenile polyp.

A Pediatric Case of Inverted Meckel's Diverticulum Presenting with Cyclic Vomiting-like Symptoms: A Case Report and Literature Review.

Asymptomatic Meckel's diverticulum cases are not uncommon, leading to diagnostic difficulties in cases of atypical presentations with only gastrointestinal symptoms other than bloody stool. A nine-year-old boy diagnosed as having cyclic vomiting because of recurrent abdominal pain and vomiting for 6 months was referred to our institute and hospitalized due to worsening symptoms. After admission, abdominal ultrasonography showed the multiple concentric ring sign and a pseudokidney sign at the lower ileum, leading to the diagnosis of ileo-ileal intussusception, but the gastrointestinal symptoms and ultrasonic findings disappeared spontaneously. Transanal, double-balloon, intestinal endoscopy demonstrated a pedunculated polyp-like structure, and surgical resection was performed. An inverted diverticulum was found in the resected intestinal lumen, and ectopic gastric mucosa was identified histologically, leading to the diagnosis of inverted Meckel's diverticulum. In pediatric cases involving periodic attacks of vomiting and abdominal pain, unnecessary emergent surgery could be avoided by cautious imaging evaluation and consideration of ileo-ileal intussusception with advanced lesions of an inverted Meckel's diverticulum as a differential diagnosis, without facilely diagnosing cyclic vomiting. In addition, previous reports of inverted Meckel's diverticulum were reviewed, and the results were compared between adult and pediatric groups in each category.

Impact of Anti-TNFα Treatment on the Humoral Response to the BNT162b2 mRNA COVID-19 Vaccine in Pediatric Inflammatory Bowel Disease Patients.

The efficacy of the COVID-19 mRNA vaccine, including the third vaccination in pediatric inflammatory bowel disease (PIBD) patients is not fully understood. This study aimed to evaluate the humoral immunogenicity of the BNT162b2 vaccine and the changes in durability until 20-28 weeks after the initial vaccine series in PIBD patients on immunosuppressive drugs. The safety of the initial vaccine series and the booster effect of the third vaccination were also evaluated. A single-center, prospective cohort study was conducted, and 63 participants (anti-TNFα: 11; non-anti-TNFα: 31; 5-ASA: 21), with a mean age of 15.2 (range 9.6-17.9) years, were enrolled. All PIBD patients were seroconverted, with no serious short-term AEs. PIBD patients on anti-TNFα had significantly lower antibody titers than those on other medications at all measurement points. Furthermore, antibody titers waned over time with anti-TNFα and were significantly lower at 20-28 weeks than at 3-9 weeks after a two-vaccine series. In all 10 patients (anti-TNFα: 5; non-anti-TNFα including 5-ASA: 5), the third vaccination led to antibody concentrations significantly higher than those at the same time point after the second vaccination. PIBD patients on anti-TNFα need to remain vigilant about COVID-19 even after two vaccinations, and a third vaccination may be considered.

Expression of Oncogenic Molecules in Pediatric Ulcerative Colitis.

INTRODUCTION: Long-term disease duration of ulcerative colitis (UC) is known to increase the risk of developing colorectal cancer in adults; however, this association has not been genetically analyzed in children with UC. Herein, we examined the expression of cancer-related genes in the colonic mucosa of pediatric UC patients and their risk of developing colorectal cancer. METHODS: Microarray analysis of cancer-related gene expression was conducted on rectal mucosa biopsy specimens randomly selected from pediatric cases, including 4 active-phase UC cases, 3 remission-phase UC cases, and 3 irritable bowel syndrome control cases. The subject pool was then expanded to 10 active-phase cases, 10 remission-phase cases, and 10 controls, which were analyzed by real-time polymerase chain reaction (PCR) and immunohistochemical staining. RESULTS: The microarray results indicated significantly higher expression levels of cancer-related genes PIM2 and SPI1 in the active group than in the remission and control groups (p < 0.05). Real-time PCR confirmed that PIM2 and SPI1 expression levels were significantly higher, whereas TP53 and APC expression levels were significantly lower, in the active-phase group than in the remission and control groups (p < 0.05). Immunohistochemical staining for PIM2, SPI1, TP53, and APC proteins supported the real-time PCR results. CONCLUSIONS: Expression levels of previously unreported cancer-related genes in adult UC patients were significantly higher in pediatric UC patients than in controls. Inflammation of the gastrointestinal mucosa increased the expression levels of cancer-related genes even in childhood-onset UC cases, suggesting that chronic inflammation from childhood may increase the risk of colorectal cancer development.

Evaluating Small Intestinal Motility in a Rat Model of Adolescent Irritable Bowel Syndrome.

Objectives: The correlation between altered small intestinal motility and irritable bowel syndrome is not well evaluated. This study aimed to assess the small intestinal and colonic transits in an adolescent irritable bowel syndrome rat model with restraint stress and determine the role of small intestinal motility in the irritable bowel syndrome pathophysiology. Materials: Restraint stress was utilized to prepare adolescent irritable bowel syndrome rat models that were evaluated for clinical signs, including stool frequency and diarrhea. The small intestinal motility and transit rate were also evaluated. Methods: The amounts of mRNA encoding corticotropin-releasing hormone, mast cell, and serotonin (5-Hydroxytryptamine) receptor 3a were quantified using real-time polymerase chain reaction; the 5-Hydroxytryptamine expression was evaluated using immunostaining. Results: Restraint stress significantly increased the number of fecal pellet outputs, stool water content, and small intestinal motility in the adolescent irritable bowel syndrome rat models. There was no difference in real-time polymerase chain reaction results; however, immunostaining analysis revealed that 5-Hydroxytryptamine expression in the small intestine was significantly increased in the adolescent irritable bowel syndrome rat models. Conclusions: In the rat model of adolescent irritable bowel syndrome with restraint stress, we observed an increase in small intestinal and colonic motility. In the small intestine, enhanced 5-Hydroxytryptamine secretion in the distal portion may be involved in increasing the small intestinal motility. Although the present study focused on 5-Hydroxytryptamine, further investigation of other factors that regulate intestinal peristalsis may lead to the establishment of more effective treatment methods for adolescent irritable bowel syndrome.

Novel pediatric granulomatosis with polyangiitis with a marked bloody pericardial effusion and bloody stool: a case report.

BACKGROUND: Granulomatosis with polyangiitis (GPA) is a syndrome of refractory vasculitis involving the upper respiratory tract, lungs, kidneys, and systemic small and medium-sized arteries that affects all age groups. No pediatric case with a bloody pericardial effusion resulting in cardiac tamponade and co-existing hematochezia has been reported. CASE PRESENTATION: A 14-year-old boy was referred for evaluation of prolonged fever, chest pain, and intermittent hematochezia. Diagnostic imaging showed a prominent pericardial effusion. Immediately after admission, his systolic blood pressure decreased. Emergent pericardiocentesis resulted in aspiration of a massive amount of bloody pericardial fluid. This was diagnosed as cardiac tamponade because his blood pressure recovered immediately after the drainage. The patient had an elevated serine proteinase 3-anti-neutrophil cytoplasmic antibody (PR3-ANCA) level on serological examination. Head MRI showed thickening of nasal and sinusoidal mucosa and a cystic mass in the left sphenoid sinus. After ruling out malignancy based on the cytology of the effusion, chest MRI, and gallium scintigraphy, total colonoscopy showed multiple irregular-shaped aphthae from the right transverse colon to the cecum on the contralateral side of the mesenteric attachments. Biopsy specimens of aphthous lesions confirmed necrotizing granulomatous inflammation. A diagnosis of GPA was made based on these findings, and oral prednisolone (PSL) and azathioprine were started. The hematochezia disappeared rapidly, and no recurrence of pericardial effusion was seen after PSL tapering was completed. The PR3-ANCA level decreased into the normal range immediately after the initial therapy. CONCLUSIONS: Pericarditis is a common cardiac complication of GPA, but there have been no reports of resultant cardiac tamponade. This is the first case of pediatric GPA with cardiac and gastrointestinal complications preceding the common symptoms such as respiratory or renal symptoms. A case of pediatric GPA with hematochezia is also extremely rare. In conclusion, serial measurement of ANCA levels is important in patients with persistent fever and bloody stool, such as in inflammatory bowel disease, to make the diagnosis of a vasculitic syndrome.

Linked colour imaging versus white-light colonoscopy for the detection of flat colorectal lesions: A randomized controlled trial.

AIM: Linked colour imaging is an image-enhanced endoscopy system that emphasizes the red portion of the mucosa's colour. Our aim was to compare the effectiveness of linked colour imaging with white-light colonoscopy for the detection of flat-type colorectal polyps. METHOD: This was a single-centre, randomized controlled trial. Enrolled patients were those aged ≥50 years undergoing cap-assisted colonoscopy for colorectal cancer screening. They were randomized in a 1:1 ratio for observation using linked colour imaging or white-light colonoscopy. All colorectal polyps detected were removed or biopsied. The primary outcome was the number of flat-type polyps per patient in patients in whom flat polyps were detected. Secondary outcomes included adenoma and polyp detection rates. RESULTS: There were 302 subjects randomized: 152 to linked colour imaging and 150 to white-light colonoscopy. There were no differences in the clinical features between the two arms. The number of flat polyps detected per patient using linked colour imaging was approximately twice that with white light (2.9 ± 3.0 vs 1.2 ± 1.6, p = 0.045). Linked colour imaging also proved superior to white-light colonoscopy in terms of adenoma and polyp detection rates [adenomas 66% (101/152) vs 49% (73/150), p = 0.0024; polyps 69% (105/152) vs 55% (82/150), p = 0.013]. The ratio of polyps detected in the right colon compared with those detected in the left colon was significantly greater using linked colour than white-light imaging (168/64 vs 93/84; p < 0.001). CONCLUSION: Compared with white-light colonoscopy, linked colour imaging improved adenoma and polyp detection rates, including detection of flat-type colorectal polyps.

Effectiveness of Biological Agents in the Treatment of Pediatric Patients with Crohn's Disease and Anal Fistulae.

INTRODUCTION: Anal fistulae have a significant impact on the quality of life of patients with Crohn's disease (CD). In this cross-sectional study, we aimed to determine whether biological agents were effective in treating anal fistulae in patients with CD. METHODS: Fifty-three patients diagnosed with CD were retrospectively enrolled. Their data regarding symptoms, treatments, and disease progression from January 2007 to December 2016 were reviewed from the medical records. Fifteen (28%) patients with CD were complicated by anal fistulae. RESULTS: The male-to-female ratio was 13:2, and the mean age at onset was 11 years and 6 months. Among the 15 patients, 14 (93%) had anal fistulae as an initial symptom. Almost all patients were treated by providing elemental diet, 5-aminosalicylic acid, and steroids as induction therapy. Biological agents were used in 8 patients (53.3%), and fistula closure was confirmed in all of them. Among the 7 patients not treated with biological agents, 1 (14.3%) had a recurrent anal fistula, while another had incomplete fistula closure. Regarding surgical management, 2 patients were treated using the seton method, and no patients required a colostomy. CONCLUSION: Treatment with biological agents is highly effective concerning the closure of anal fistulae in patients with CD, and reducing pain may improve their quality of life.

Eradication therapy for Helicobacter pylori infection based on the antimicrobial susceptibility test in children: A single-center study over 12 years.

BACKGROUND: Helicobacter pylori (H. pylori) infection causes chronic gastritis, duodenal and to a lesser extent, gastric ulcers, and gastric cancer. Most H. pylori infections are acquired in childhood, and effective treatment of childhood infection is very important. Esophagogastroduodenoscopy (EGD) is useful for endoscopic diagnosis, mucosal tissue biopsy, and culture examination for H. pylori in children and adults. In this paper, we report results of susceptibility tests and eradication rates in H. pylori-positive children who underwent EGD over a 12-year period. MATERIALS AND METHODS: The subjects were H. pylori-positive pediatric patients who had gastrointestinal symptoms and underwent EGD in the Department of Pediatrics, Juntendo University Hospital (January 2007-December 2018). Patients underwent serum IgG antibody tests, fecal antigen tests, or urea breath tests, and subsequently, culture tests by gastric mucosal biopsy during EGD. H. pylori positivity was defined as a positive result on both tests. Patients received triple therapy for 14 days using our regimen, and eradication was assessed at 2, 6, and 12 months after therapy. RESULTS: Forty-five patients were H. pylori-positive, and the overall clarithromycin (CAM) resistance rate was 71.1 % (32/45). The CAM resistance rate for the 2013-2018 period was significantly higher than the 2007-2012 period (52.6% vs. 84.6%, P < 0.05). According to the results of the antimicrobial susceptibility test, we prescribed effective antibiotics, and this resulted in a primary eradication rate of 97.7%. CONCLUSIONS: We suggest that antimicrobial susceptibility testing can significantly improve rates of primary eradication of H. pylori infection.

Ultrasonographic study of intestinal Doppler blood flow in infantile non-IgE-mediated gastrointestinal food allergy.

BACKGROUND: Although non-IgE-mediated gastrointestinal food allergy has increased rapidly in Japan, a small number of reports has evaluated B-mode and Doppler ultrasonographic findings in the acute phase of infantile gastrointestinal milk allergy. The aim of the present study was to compare the diagnostic utility of ultrasonographic findings and laboratory allergic data in non-IgE-mediated infantile gastrointestinal milk allergy. METHODS: Sixteen cases of active non-IgE-mediated infantile gastrointestinal milk allergy, diagnosed by food elimination tests and oral food challenge tests (OFCTs) (group A), 15 cases of acute viral gastroenteritis (AGE) (group B), and 15 controls (group C) were enrolled. 1) B-mode abdominal ultrasound findings, 2) laboratory allergic data including eosinophil counts (Eos), serum IgE, and the antigen-specific lymphocyte proliferation test (ALPT) against milk protein, and 3) vessel density (VD) indirectly quantified by gastrointestinal Doppler flow at jejunum, ileum, and sigmoid colonic mucosae were evaluated and compared among the groups. RESULTS: In the small intestine, wall thickening, dilation, mesenteric thickening, and poor peristalsis were found in 100%, 62.5%, 93.7%, and 100%, respectively, in group A. Eos, IgE, ALPT, and VD were positive in 25.0%, 0%, 87.5%, and 100%, respectively, in group A. Small intestinal VD was significantly greater in group A than in groups B (jejunum p < .001; ileum p < .001) and C (jejunum p < .001; ileum p < .001), with no significant differences between groups B and C (jejunum: p = .74; ileum: p = .73). CONCLUSIONS: Abdominal Doppler ultrasonography and small intestinal VD at symptomatic state can support the diagnosis and evaluation of non-IgE-mediated infantile gastrointestinal milk allergy with symptoms of vomiting, diarrhea, and failure to thrive.

Multifocal granular cell tumors of the gastrointestinal tract: Immunohistochemical findings compared with those of solitary tumors.

Granular cell tumors (GCT) are infrequently found in the gastrointestinal tract (GIT), and only four previous reports have described lesions occurring simultaneously in different sites. The present case of 11 GCT, located in the esophagus, stomach, colon and pericolic adipose tissue, occurred in a 50-year-old Japanese woman. All GCT appeared histologically benign and there was no sign of recurrence at 3 years after surgery. Immunohistochemical analysis and comparison between this case of multifocal GCT and six cases of solitary benign GCT of the GIT, which were taken from the files of the Department of Pathology at Kitasato University (1986-2000), demonstrated the follow-ing: (1) all diffusely expressed S-100, DCC and bcl-2, and (2) median labeling indices for Ki-67, cyclin D1, p53 (Pab1801), and p21WAF1/CIP1 of 4%, 24%, 1% and 28%, respectively, for the multifocal tumors, and 3.5%, 23%, 1% and 29%, respectively, for the solitary lesions, with no significant difference between the two groups. Thus, the expression of cyclin D1 and p21WAF1/CIP1 may be involved in the tumorigenesis of both types of GCT. The present case emphasizes the need to evaluate the entire GIT when a single GCT is identified. Multifocal lesions should be treated conservatively by local excision because, as with the solitary tumors, they exhibit a benign biological behavior, consistent with their low Ki-67 immunoreactivity.