Malignant tumors associated with juvenile polyposis syndrome in Japan

Chinese national clinical practice guidelines on prevention, diagnosis and treatment of early colorectal cancer

BACKGROUND

The incidence and mortality of colorectal cancer (CRC) in China are increasing in recent years. The clarified pathogenesis and detectable precancerous lesions of CRC make it possible to prevent, screen, and diagnose CRC at an early stage. With the development of endoscopic and surgical techniques, the choice of treatment for early CRC is also worth further discussion, and accordingly, a standard follow-up program after treatment needs to be established.

METHODS

This clinical practice guideline (CPG) was developed following the recommended process of the World Health Organization, adopting Grading of Recommendations Assessment, Development and Evaluation (GRADE) in assessing evidence quality, and using the Evidence to Decision framework to formulate clinical recommendations, thereby minimizing bias and increasing transparency of the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guides to ensure the guideline's completeness and transparency.

RESULTS

This CPG comprises 46 recommendations concerning prevention, screening, diagnosis, treatment, and surveillance of CRC. In these recommendations, we have indicated protective and risk factors for CRC and made recommendations for chemoprevention. We proposed a suitable screening program for CRC based on the Chinese context. We also provided normative statements for the diagnosis, treatment, and surveillance of CRC based on existing clinical evidence and guidelines.

CONCLUSIONS

The 46 recommendations in this CPG are formed with consideration for stakeholders' values and preferences, feasibility, and acceptability. Recommendations are generalizable to resource-limited settings with similar CRC epidemiology pattern as China.

Studying the Effect of the Host Genetic Background of Juvenile Polyposis Development Using Collaborative Cross and Smad4 Knock-Out Mouse Models

Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder characterized by multiple juvenile polyps in the gastrointestinal tract, often associated with mutations in genes such as Smad4 and BMPR1A. This study explores the impact of Smad4 knock-out on the development of intestinal polyps using collaborative cross (CC) mice, a genetically diverse model. Our results reveal a significant increase in intestinal polyps in Smad4 knock-out mice across the entire population, emphasizing the broad influence of Smad4 on polyposis. Sex-specific analyses demonstrate higher polyp counts in knock-out males and females compared to their WT counterparts, with distinct correlation patterns. Line-specific effects highlight the nuanced response to Smad4 knock-out, underscoring the importance of genetic variability. Multimorbidity heat maps offer insights into complex relationships between polyp counts, locations, and sizes. Heritability analysis reveals a significant genetic basis for polyp counts and sizes, while machine learning models, including k-nearest neighbors and linear regression, identify key predictors, enhancing our understanding of juvenile polyposis genetics. Overall, this study provides new information on understanding the intricate genetic interplay in the context of Smad4 knock-out, offering valuable insights that could inform the identification of potential therapeutic targets for juvenile polyposis and related diseases.

Early-Onset Gastrointestinal Malignancies: An Investigation into a Rising Concern

There is growing recognition of early-onset gastrointestinal (GI) malignancies in young adults < 50 years of age. While much of the literature has emphasized colorectal cancer, these also include esophageal, gastric, liver, pancreatic, and biliary tract malignancies. Various factors, including lifestyle, hereditary, and environmental elements, have been proposed to explain the rising incidence of GI malignancies in the younger population. This review aims to provide an overview of the recent literature, including global trends and information regarding genetic and environmental risk factors.

Sporadic gastric juvenile polyposis with a novel SMAD4 nonsense mutation in a mosaic pattern

A 50-year-old female was diagnosed with gastric hyperplastic polyps 7 years before and was followed up at another hospital. She was referred to our hospital because of the growth of gastric polyps and progression of anemia. She had no family history of polyposis. The polyps were observed only in the stomach, increased in size and number, and the erythematous edema got worse. Endoscopic mucosal resection (EMR) of the gastric polyp was performed. Pathologically, the gastric polyp was hamartomatous polyp, and the intervening mucosa between polyps showed no atypical structure without inflammation. Given that gastric juvenile polyposis (GJP) was clinically suspected, a genetic test using peripheral blood was performed. Target resequencing and Sanger sequencing analysis revealed a nonsense mutation in the SMAD4 gene at codon 169. The mutation was detected at a low frequency of 11%, and considered a mosaic mutation. Therefore, she was diagnosed with a sporadic GJP, and total gastrectomy was performed. Immunostaining of SMAD4 for the resected specimen showed a mixture of stained and unstained area in the epithelium of the polyp, indicating partial loss of SMAD4 expression. To our knowledge, this is the first reported case of GJP with a nonsense SMAD4 mutation at codon 169 in a mosaic pattern.

Juvenile polyposis syndrome with gastric and duodenal polyposis presenting with refractory anemia and protein-leakage gastroenteropathy in a patient with SMAD4 mutation: a case report

BACKGROUND

Juvenile polyposis syndrome (JPS) is an autosomal dominant, inherited disorder characterized by multiple hyperproliferative polyps of the gastrointestinal tract, particularly of the colon, rectum, and stomach. SMAD4 mutations are frequently associated with multiple polyposis of the stomach; the condition causes severe bleeding and hypoproteinemia, which may progress to severe dysplasia and adenocarcinoma formation. We report our experience with the first case of total gastrectomy with pancreaticoduodenectomy following two partial jejunectomies for JPS, who presented with refractory anemia and protein-losing gastroenteropathy due to polyposis of the stomach and duodenum.

CASE PRESENTATION

A 33-year-old Japanese man presented with the chief complaint of shortness of breath on exertion. His family history included gastric polyposis (mother, aunt, and cousin) and cerebral infarction (grandmother). Blood testing at the initial visit indicated iron-deficiency anemia, whereas endoscopy revealed multiple polyps in the duodenum and jejunum. Genetic testing revealed a 4 bp deletion (TGAA) in exon 5 of the SMAD4 gene; two partial small bowel resections were performed, but polyps grew in the remaining stomach, duodenum, and small intestine. The patient developed hypoalbuminemia and anemia, and required central venous nutrition and blood transfusion. However, because the hyponutrition and anemia remained poorly controlled, a total gastrectomy with concomitant pancreaticoduodenectomy was performed. Malnutrition and anemia improved, and there was no polyp recurrence in the remaining intestinal tract at 18 months after the surgery.

CONCLUSIONS

We report a case of JPS with refractory anemia and protein-losing gastroenteropathy that was treated with total gastrectomy with concomitant pancreaticoduodenectomy. Although the surgery was highly invasive, the patient's nutritional status and anemia improved postoperatively, and the treatment was successful. However, to determine the appropriate surgical procedure, a detailed examination of the gastrointestinal lesions and the effects of the surgical invasion on nutritional status must be undertaken.

Genotype-phenotype correlation of BMPR1a disease causing variants in juvenile polyposis syndrome

BACKGROUND

Juvenile Polyposis Syndrome (JPS) is an autosomal dominant condition with hamartomatous polyps in the gastrointestinal tract, associated with an increased risk of gastrointestinal malignancy. Disease causing variants (DCVs) in BMPR1a or SMAD4 account for 45-60% of JPS cases, with BMPR1a DCVs accounting for 17-38% of JPS cases. Within those with either a BMPR1a or SMAD4 DCV, there is phenotypic variability in location of polyps, risk of malignancy and extra-intestinal manifestations with limited published reports of gene-phenotype association or genotype-phenotype correlation. We aimed to identify any gene-phenotype association or genotype-phenotype correlation in BMPR1a to inform surveillance recommendations, and gene-specific modification to the ACMG classification of pathogenicity of DCVs.

METHODS

A literature search was performed through EMBASE, MEDLINE and PubMed. Studies that were included explored BMPR1a DCV-related JPS or contiguous deletion of PTEN and BMPR1a. Data was also drawn from the BMPR1a specific databases on LOVD and ClinVar.

RESULTS

There were 211 DCVs in BMPR1a identified, 82 from patients with JPS in the literature, and 17 from LOVD and 112 from ClinVar classified as pathogenic or likely pathogenic. These included missense, nonsense and frameshift variants and large deletions, occurring across all functional domains of the gene. Unlike in SMAD4 carriers, gastric polyposis and malignancy were not identified in our review in BMPR1a carriers, but colonic polyposis and malignancy occurred in carriers of either BMPR1a or SMAD4 DCVs. Those with contiguous deletion of PTEN and BMPR1a can present with JPS of infancy, with a severe phenotype of GI bleeding, diarrhoea, exudative enteropathy and rectal prolapse. No specific BMPR1a genotype-phenotype correlation could be ascertained including by variant type or functional domain.

CONCLUSION

Phenotypic characteristics cannot be used to inform variant location in BMPR1a. However, the phenotypic characteristics of BMPR1a DCV carriers, being almost exclusively related to the colon and rectum, can assist in pathogenicity assessment of BMPR1a variants. Given these findings, we propose that carriers of BMPR1a DCVs should only require surveillance for colorectal polyps and malignancy, and that surveillance for gastric polyps and malignancy may be unnecessary. However variant location within BMPR1a does not support differential surveillance recommendations.

Occurrence of gastric cancer in patients with juvenile polyposis syndrome: a systematic review and meta-analysis

BACKGROUND AND AIMS

The true rate of gastric cancer (GC) in juvenile polyposis syndrome (JPS) is unknown because of its rarity and ascertainment bias in published literature. To better assess this, we conducted a systematic review and meta-analysis.

METHODS

MEDLINE, Embase, and Scopus databases were searched for the key words juvenile polyposis syndrome, juvenile polyps, stomach cancer, GC, SMAD4, BMPR1A, hamartomatous polyposis syndrome, hamartomas, and hereditary cancers for studies reporting upper GI manifestations in JPS. The primary outcome was the reported occurrence of GC in JPS. We then compared GC occurrence based on the presence or absence of pathogenic germline variants (PGVs) and in untested patients.

RESULTS

Eleven studies including 637 patients were included. The pooled occurrence of GC was 3.5% (95% confidence interval [CI], 1.8-5.2; I² = 12.3%) at a median age of 42.5 years (range, 15-57.6). The pooled occurrence of GC in patients with SMAD4 PGV was 10.1% (95% CI, 3.2-16.8%; I² = 54.7%). GC was reported in only 1 BMPR1A PGV carrier and was not reported in patients without an identifiable PGV. In patients with prior germline testing, the risk of GC was higher in SMAD4 PGV carriers (odds ratio, 11.6; 95% CI, 4.6-29.4; I² = 18.3%) compared with patients without SMAD4 PGV. In JPS patients with unknown status of germline testing, pooled occurrence of GC was 7.5% (95% CI, 0-15.5). There was an overall moderate risk of bias in the studies.

CONCLUSIONS

GC is highest in SMAD4-associated JPS and was not reported in patients without identifiable PGVs. The value of GC surveillance in BMPR1A PGV carriers and JPS patients without an identifiable PGV is questionable. Germline testing should be performed in all JPS patients to inform GC risk discussion and utility of surveillance.

Clinical Spectrum and Science Behind the Hamartomatous Polyposis Syndromes

The hamartomatous polyposis syndromes are a set of clinically distinct disorders characterized by the occurrence of hamartomatous polyps in the gastrointestinal tract. These syndromes include juvenile polyposis syndrome, Peutz-Jeghers syndrome, and PTEN hamartoma tumor syndrome. Although each of the syndromes has distinct phenotypes, the hamartomatous polyps can be challenging to differentiate histologically. Additionally, each of these syndromes is associated with increased lifetime risks of gene-specific and organ-specific cancers, including those outside of the gastrointestinal tract. Germline pathogenic variants can be identified in a subset of individuals with these syndromes, which facilitates molecular diagnosis and subsequent gene-enabled management in the setting of genetic counseling. Although the malignant potential of hamartomatous polyps remains elusive, timely recognition of these syndromes is important and enables presymptomatic cancer surveillance and management before symptom exacerbation. Presently, there are no standard agents to prevent the development of polyps and cancers in the hamartomatous polyposis syndromes.

Genetic Predisposition to Colorectal Cancer: How Many and Which Genes to Test?

Colorectal cancer is one of the most common tumors, and genetic predisposition is one of the key risk factors in the development of this malignancy. Lynch syndrome and familial adenomatous polyposis are the best-known genetic diseases associated with hereditary colorectal cancer. However, some other genetic disorders confer an increased risk of colorectal cancer, such as Li-Fraumeni syndrome (TP53 gene), MUTYH-associated polyposis (MUTYH gene), Peutz-Jeghers syndrome (STK11 gene), Cowden syndrome (PTEN gene), and juvenile polyposis syndrome (BMPR1A and SMAD4 genes). Moreover, the recent advances in molecular techniques, in particular Next-Generation Sequencing, have led to the identification of many new genes involved in the predisposition to colorectal cancers, such as RPS20, POLE, POLD1, AXIN2, NTHL1, MSH3, RNF43 and GREM1. In this review, we summarized the past and more recent findings in the field of cancer predisposition genes, with insights into the role of the encoded proteins and into the associated genetic disorders. Furthermore, we discussed the possible clinical utility of genetic testing in terms of prevention protocols and therapeutic approaches.

A case report of adult juvenile polyposis syndrome with SMAD4 pathogenic variant

Background

Juvenile polyposis syndrome (JPS) is a rare autosomal dominant disorder that is a type of hamartomatous polyp syndrome, and its incidence rate is approximately 1/100000. The main clinical feature is the presence of multiple juvenile polyps in the gastrointestinal tract, most often in the colorectal tract. We present a case of juvenile polyposis syndrome with massive gastric polyposis.

Case presentation

A 50-year-old male was admitted to the hospital due to abdominal distension and poor appetite. Gastroscopy revealed a large number of gastric polyps. Pathological findings revealed gastric juvenile polyps. Genetic testing revealed that he and his brother both carried SMAD4: c.266_269del germline pathogenic variant. The final diagnosis was juvenile polyposis syndrome of the stomach. He once suffered from colon cancer and bladder cancer. One of his brothers died of colon cancer, and the other brother suffered from colon polyps.

Conclusions

Gastric involvement in juvenile polyposis syndrome is relatively rare. When massive gastric polyposis is found, gene detection should be carried out as soon as possible, so that rapid diagnosis and treatment can be obtained.

A New SMAD4 Splice Site Variant in a Three-Generation Italian Family with Juvenile Polyposis Syndrome

Juvenile polyposis syndrome (JPS) is an autosomal dominant disorder characterized by hyperplastic polyps in the upper and lower gastrointestinal (GI) tract with a high risk of developing GI cancers. We have described a three-generation Italian family with all the spectrum of SMAD4 phenotype. A multigene panel test was performed on the genomic DNA of the proband by next-generation sequencing, including genes related to hereditary GI tumor syndromes. Molecular analysis revealed the presence of the c.1140-2A>G substitution in the SMAD4 gene, a novel splice variant that has never been described before. Our family is remarkable in that it illustrates the variable expressivity of the SMAD4 phenotype within the same family. The possibility of phenotype variability should also be considered within family members carrying the same mutation. In JPS, a timely genetic diagnosis allows clinicians to better manage patients and to provide early surveillance and intervention for their asymptomatic mutated relatives in the early decades of life.

Adenomatous Polyposis Phenotype in BMPR1A and SMAD4 Variant Carriers

INTRODUCTION

Variants in SMAD4 or BMPR1A cause juvenile polyposis syndrome, a rare autosomal dominant condition characterized by multiple gastrointestinal hamartomatous polyps. A phenotype of attenuated adenomatous polyposis without hamartomatous polyps is rare.

METHODS

We describe a retrospective cohort of individuals with SMAD4 or BMPR1A heterozygous germline variants, having ≥10 cumulative colorectal adenomas and/or colorectal cancer without hamartomatous polyps. All individuals had multigene panel and duplication/deletion analysis to exclude other genetic syndromes.

RESULTS

The study cohort included 8 individuals. The pathogenic potential of the variants was analyzed. Variants detected included 4 missense variants, 1 nonsense variant, 1 splice site variant, and 2 genomic deletions. Features of pathogenicity were present in most variants, and cosegregation of the variant with polyposis or colorectal cancer was obtained in 7 of the 8 families. Three of 8 individuals had colorectal cancer (age less than 50 years) in addition to the polyposis phenotype. Two individuals had extraintestinal neoplasms (pancreas and ampulla of Vater).

DISCUSSION

The clinical phenotype of SMAD4 and BMPR1A variants may infrequently extend beyond the classical juvenile polyposis syndrome phenotype. Applying multigene panel analysis of hereditary cancer-related genes in individuals with unexplained polyposis can provide syndrome-based clinical surveillance for carriers and their family members.

Juvenile polyposis: Focus on less described manifestations

Juvenile polyposis represents an heterogeneous disease as different genetic dominant backgrounds have been evidenced leading to different clinical presentations. It is associated in some patients with a different syndrome, Hereditary Hemorragic Telangiectasia, justifying a complementary and different management. Recent international recommendations help in managing this very rare disease, and this management should probably be restricted to expert centers able to take care of the multiple manifestations and risks of these patients and families. This paper will focus on the poorly known and evaluated aspects of juvenile polyposis, excluding the colonic involvement and epidemiology that are addressed in a different article of this issue.

Laparoscopic total gastrectomy performed for juvenile polyposis of the stomach: A case report

INTRODUCTION AND IMPORTANCE

Juvenile polyposis of the stomach (JPST) is a very rare disease and has been reported to have malignant potential. Total gastrectomy has been recommended as a standard treatment. Recently, the usefulness of laparoscopic surgery for this disease has been reported; however, in laparoscopic surgery, maintaining the surgical space is difficult because of the distended and thickened stomach wall that polyposis causes.

CASE PRESENTATION

A 64-year-old woman was admitted to our hospital because she became malnourished due to loss of appetite. She had no family history of gastrointestinal polyposis and was diagnosed with gastric polyposis and polyp-related anemia eight years previously. She received endoscopic submucosal dissection of early gastric cancer twice in another hospital. Thereafter, the patient received an annual upper gastrointestinal endoscopy and took iron supplements for anemia due to occasional bleeding from polyps. However, the number of polyps increased over time. Enhanced computed tomography showed gastric wall thickening and multiple gastric polyps. She was diagnosed as having JPST and underwent laparoscopic total gastrectomy. She was discharged on postoperative Day 10.

CLINICAL DISCUSSION

In the present case, similar to previous cases, standard laparoscopic surgery could be performed although the patient had excessive distention and congestion of the stomach. This report suggests that laparoscopic surgery is a safe and feasible option for patients with JPST and is preferable because of better cosmetic effects, especially for young female patients.

CONCLUSION

We successfully performed laparoscopic surgery to treat a rare case of JPST.

Familial and hereditary gastric cancer, an overview

There are three major hereditable syndromes that affect primarily the stomach: hereditary diffuse gastric cancer (HDGC), gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) and familial intestinal gastric cancer (FIGC). HDGC is caused by germline mutations in CDH1 gene that occur in 10-40% of HDGC families and, in a minority of cases, by mutations in CTNNA1 gene. GAPPS is caused by germline mutations in the promoter 1B of APC gene, and the genetic cause of FIGC is not fully elucidated. Gastric cancer can also be observed as part of other inherited cancer disorders, namely in familial adenomatous polyposis, MUTYH-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome, Lynch syndrome, Li-Fraumeni syndrome, Cowden syndrome, and hereditary breast and ovarian cancer syndrome. In this article, the state of the art of familial gastric cancer regarding the clinical, molecular and pathology features is reviewed, as well as the practical aspects for a correct diagnosis and clinical management.

Hereditary pancreatic cancer

Pancreatic cancer is associated with both family and hereditary cancer syndromes. Multigene panel testing for pancreatic cancer detected the germline variants BRCA1/2, PALB2, ATM, TP53, MLH1, STK11/LKB1, APC, CDKN2A, and SPINK1/PRSS1 as high-risk genes. A latest genome-wide association study revealed the common, but low-risk germline variants in pancreatic cancer patients. Active pancreatic surveillance using magnetic resonance imaging and endoscopic ultrasound is recommended for high-risk individuals who have a family history of pancreatic cancer or harbor these germline pathogenic variants to improve the detection rate and prognosis of pancreatic cancer. Since poly-ADP-ribose polymerase (PARP) inhibitor has been shown to be effective in improving the prognosis of BRCA-positive pancreatic cancer as well as hereditary breast and ovarian cancer syndrome, PARP inhibitor therapy is currently being applied as precision medicine to pancreatic cancer patients harboring the BRCA1/2 germline variant. This review highlights the importance of surveillance for germline pathogenic variants in pancreatic cancer and is expected to lead to improvements in the diagnosis and prevention of pancreatic cancer as well as facilitate the development of effective therapeutic strategies and precision medicine.

Hamartomatous polyposis syndrome associated malignancies: Risk, pathogenesis and endoscopic surveillance

Hamartomatous polyposis syndromes (HPS) are a heterogeneous spectrum of diseases that are characterized by diffuse hamartomatous polyps lining the gastrointestinal (GI) tract together with extra-GI manifestations. Classical HPS includes juvenile polyposis syndrome, Peutz-Jeghers syndrome, PTEN hamartoma tumor syndrome and hereditary mixed polyposis syndrome. Patients with HPS have a higher risk of GI and extra-GI malignancies than the general population, although the underlying mechanisms remain unclear and are obviously different from the carcinogenesis of classical adenocarcinoma and colitis-associated malignancy. In this review we aimed to clarify the risks, possible mechanism and endoscopic surveillance of HPS-associated GI malignancies.

Small Bowel Epithelial Precursor Lesions: A Focus on Molecular Alterations

The wider use of gastrointestinal endoscopic procedures has led to an increased detection of small intestinal preneoplastic and neoplastic epithelial lesions, most of which are identified in the duodenum and ampullary region. Like their malignant counterparts, small intestinal glandular precursor lesions, which include adenomas and hamartomas, may arise sporadically or be associated with hereditary tumor syndromes, such as familial adenomatous polyposis, MUTYH-associated polyposis, Lynch syndrome, Peutz-Jeghers syndrome, juvenile polyposis syndrome, and Cowden syndrome. In addition, dysplastic, preinvasive lesions have been observed adjacent to small bowel adenocarcinomas complicating immune-related disorders, such as celiac or Crohn’s disease. Adenomatous lesions may exhibit an intestinal-type, gastric-type, or, very rarely, serrated differentiation, related to different molecular pathogenetic mechanisms. Finally, in the background of multiple endocrine neoplasia 1 syndrome, precursor neuroendocrine growths have been described. In this review we offer a comprehensive description on the histo-molecular features of the main histotypes of small bowel epithelial precursors lesions, including: (i) sporadic adenomas (intestinal-type and gastric-type; non-ampullary and ampullary); (ii) syndromic adenomas; (iii) small bowel dysplasia in celiac and Crohn’s disease; (iv) serrated lesions; (v) hamartomatous lesions; and (vi) neuroendocrine precursor lesions.

Genetic Gastric Cancer Risk Syndromes

Purpose of review

Gastric cancer is a leading cause of cancer death in the world. Between 1% and 3% of cases are associated with specific genetic cancer risk syndromes. The purpose of this article is to review the latest insights, as well as gaps in knowledge, regarding some of the most common hereditary gastric cancer syndromes: hereditary diffuse gastric cancer (HDGC), gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS), Lynch syndrome, the adenomatous polyposis syndromes, and the hamartomatous polyposis syndromes.

Recent findings

Patients carrying pathogenic variants in CDH1, but not meeting clinical criteria for HDGC, are increasingly being identified thanks to multigene panel testing; their absence from previous analyses overestimated gastric cancer penetrance. GAPPS is a recently described hereditary gastric cancer syndrome associated with specific point mutations in the promoter 1B region of the APC gene.

Summary

Risk of gastric cancer is highest among carriers of pathogenic variants in CDH1, with cumulative incidences approximately 40% and 30% for men and women, respectively. Mutations associated with Lynch syndrome and adenomatous polyposis syndromes confer greatest risk for gastric cancer in East Asian populations. Risk of gastric cancer in GAPPS and hamartomatous polyposis syndromes is difficult to estimate due to their rarity, but mutation status likely determines risk. Future research is needed to more precisely define risk of gastric cancer in these syndromes, so strategies for screening and prophylactic gastrectomy can be optimized.

Juvenile polyposis syndrome might be misdiagnosed as familial adenomatous polyposis: a case report and literature review

BACKGROUND

Juvenile polyposis syndrome (JPS) is a rare disorder characterized by the presence of multiple juvenile polyps in the gastrointestinal tract, and germline mutations in SMAD4 or BMPR1A. Due to its rarity and complex clinical manifestation, misdiagnosis often occurs in clinical practice.

CASE PRESENTATION

A 42-year-old man with multiple pedunculated colorectal polyps and concomitant rectal adenocarcinoma was admitted to our hospital. His mother had died of colon cancer. He was diagnosed with familial adenomatous polyposis (FAP) and underwent total proctocolectomy and ileal pouch anal anastomosis. Two polyps were selected for pathological examination. One polyp had cystically dilated glands with slight dysplasia. The other polyp displayed severe dysplasia and was diagnosed as adenoma. Three years later, his 21-year-old son underwent a colonoscopy that revealed more than 50 pedunculated colorectal juvenile polyps. Both patients harbored a germline pathogenic mutation in BMPR1A. Endoscopic resection of all polyps was attempted but failed. Finally, the son received endoscopic resection of polyps in the rectum and sigmoid colon, and laparoscopic subtotal colectomy. Ten polyps were selected for pathological examination. All were revealed to be typical juvenile polyps, with cystically dilated glands filled with mucus. Thus, the diagnosis of JPS was confirmed in the son. A review of the literatures revealed that patients with JPS can sometimes have adenomatous change. Most polyps in patients with JPS are benign hamartomatous polyps with no dysplasia. A review of 767 colorectal JPS polyps demonstrated that 8.5% of the polyps contained mild to moderate dysplasia, and only 0.3% had severe dysplasia or cancer. It is difficult to differentiate juvenile polyps with dysplasia from adenoma, which could explain why juvenile polyps have been reported to have adenomatous changes in patients with JPS. Therefore, patients with JPS, especially those with concomitant dysplasia and adenocarcinoma, might be easily diagnosed as FAP in clinical practice.

CONCLUSIONS

Juvenile polyp with dysplasia is often diagnosed as adenoma, which might lead to the misdiagnosis of JPS as FAP. The differential diagnosis of JPS versus FAP, should be based on comprehensive evaluation of clinical presentation, endoscopic appearance and genetic investigations; not on the presence or absence of adenoma.

Polypoid disease of colon in children

Polyps in gastrointestinal tract are mostly benign and result from hamartomas or lymphoid hyperplasia of submucosa. They usually occur as isolated lesions in children and are referred to as juvenile polyps. Multiple polyps with inherited origin are called polyposis and can be seen as a part of the syndrome. The polyps with adenomatous histopathology have malignant potential and necessitate genetic testing and colonoscopy to define the risk of cancer. Although simple endoscopic removal is adequate in the treatment of juvenile polyps, children with familial adenomatous polyposis (FAP) need total colectomy with ileorectal anastomosis (IRA) or ileal pouch-anal anastomosis (IPAA). The timing of prophylactic colectomy and the type of surgical treatment are controversial in children. The clinical features, the assessment of cancer risk, and the alternatives of the surgical treatment of polyps are reviewed in this paper.

Ultrasonography with the colonic segment-approach for colonic polyps in children

BACKGROUND

Ultrasonography (US) has been widely applied and has validated efficacy in the diagnosis of colonic polyps in children. However, little attention has been paid to improving the detection rate of polyps, optimizing the ultrasonic examination process and reducing misdiagnosis.

OBJECTIVE

To investigate the diagnostic performance of the colonic segment-approach by US in the diagnosis of colonic polyps in pediatric patients.

MATERIALS AND METHODS

One hundred fifty-nine patients who were going to have a colonoscopy from September 2014 to August 2016 were enrolled in this study. All patients received US before colonoscopy. In a preliminary study, 50 patients were chosen to determine the interobserver agreement, with half of the cases with and half of the cases without a colonic segment-approach. The other 109 patients were examined by both approaches. The sensitivity and the specificity of each approach were compared based on the outcome of colonoscopy as the gold criteria.

RESULTS

The interobserver agreement was high (0.816 for the non-segmental approach, 0.754 for the colonic segment-approach). The diagnostic sensitivity of the colonic segment-approach was higher than that of the traditional approach (82.1% vs. 57.7%, P<0.05) with 89.3% vs. 64.2% detection rate of colonic polyps in the descending colon, 81.8% vs. 60.6% in the sigmoid colon, and 81.3% vs. 43.8% in the rectum, respectively. The specificity of both methods was 100% (95% confidence interval: 86.3%-100%).

CONCLUSION

The US colonic segment-approach can improve diagnostic sensitivity for colonic polyps as a convenient method with no special requirement for equipment and examination conditions.

Management of Juvenile Polyposis Syndrome in Children and Adolescents: A Position Paper From the ESPGHAN Polyposis Working Group

The European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Polyposis Working Group developed recommendations to assist clinicians and health care providers with appropriate management of patients with juvenile polyposis. This is the first juvenile polyposis Position Paper published by ESPGHAN with invited experts. Many of the published studies were descriptive and/or retrospective in nature, consequently after incorporating a modified version of the GRADE system many of the recommendations are based on expert opinion. This ESPGHAN Position Paper provides a guide for diagnosis, assessment, and management of juvenile polyposis syndrome in children and adolescents, and will be helpful in the appropriate management and timing of procedures in children and adolescents. The formation of international collaboration and consortia is proposed to monitor patients prospectively to advance our understanding of juvenile polyposis conditions.

Non-familial juvenile polyposis of the stomach with gastric cancers: a case report

Background

Juvenile polyposis is an autosomal dominant inherited disease characterized by the development of numerous hamartomatous and nonneoplastic polyps of the gastrointestinal tract. Juvenile polyposis has also recently been reported as a predisposition for gastrointestinal cancer.

Case presentation

A 63-year-old man underwent esophagogastroduodenoscopy because of anemia and hypoalbuminemia during a follow-up for gastric polyposis, which showed multiple reddish polyps and two elevated lesions in the stomach. The elevated lesions were diagnosed as well-differentiated adenocarcinomas by biopsy. He had no specific physical findings or family history. Computed tomography showed gastric wall thickening without lymphadenopathy or distant metastasis. Colonoscopy showed an adenoma in the transverse colon. He underwent laparoscopy-assisted total gastrectomy with Roux-en-Y esophagojejunostomy. The resected specimen revealed numerous variously sized non-pedunculated polyps throughout the stomach, diagnosed histopathologically as hamartomatous polyps. The two elevated lesions were diagnosed as a well-differentiated adenocarcinoma restricted to the mucosa and a well-to-poorly differentiated adenocarcinoma invading the submucosa with prominent lymphatic permeation, respectively. Genetic analysis failed to identify any germline mutations in the genes usually associated with juvenile polyposis, including SMAD4 and BMPR1A. However, based on the few characteristic physical findings and histopathological features, the final diagnosis was juvenile polyposis restricted to the stomach.

Conclusions

This patient represented a rare case of non-familial juvenile polyposis of the stomach with gastric cancers. Juvenile polyposis has malignant potential, and patients should therefore be carefully followed up. Surgical treatment, particularly total gastrectomy, is recommended as a standard treatment in patients with juvenile polyposis of the stomach with gastric cancer.