Gastrointestinal polyps in children: advances in molecular genetics, diagnosis, and management

PROTACs: Current and Future Potential as a Precision Medicine Strategy to Combat Cancer

Proteolysis targeting chimeras (PROTAC) are an emerging precision medicine strategy, which targets key proteins for proteolytic degradation to ultimately induce cancer cell killing. These hetero-bifunctional molecules hijack the ubiquitin proteasome system to selectively add polyubiquitin chains onto a specific protein target to induce proteolytic degradation. Importantly, PROTACs have the capacity to target virtually any intracellular and transmembrane protein for degradation, including oncoproteins previously considered undruggable, which strategically positions PROTACs at the crossroads of multiple cancer research areas. In this review, we present normal functions of the ubiquitin regulation proteins and describe the application of PROTACs to improve the efficacy of current broad-spectrum therapeutics. We subsequently present the potential for PROTACs to exploit specific cancer vulnerabilities through synthetic genetic approaches, which may expedite the development, translation, and utility of novel synthetic genetic therapies in cancer. Finally, we describe the challenges associated with PROTACs and the ongoing efforts to overcome these issues to streamline clinical translation. Ultimately, these efforts may lead to their routine clinical use, which is expected to revolutionize cancer treatment strategies, delay familial cancer onset, and ultimately improve the lives and outcomes of those living with cancer.

Diagnostic performance of ultrasound without any colon preparation for detecting colorectal polyps in pediatric patients

BACKGROUND

There are limited data on the sensitivity, specificity and accuracy of ultrasound for detecting colorectal polyps in children and young adults.

OBJECTIVE

To evaluate the diagnostic accuracy of ultrasound, without any colon preparation, for detecting colorectal polyps in pediatric patients and to determine the causes of false-negative results.

MATERIALS AND METHODS

We included 74 children with clinical signs like rectal bleeding, abdominal pain or diarrhea who underwent both ultrasound and colonoscopy. We evaluated the diagnostic performance of ultrasound for detecting colorectal polyps before colonoscopy, which served as the reference standard. We used Fisher exact and Student's t-tests for statistical analyses.

RESULTS

Fifteen pediatric patients were diagnosed with colorectal polyps in the transverse (n=3), descending (n=1) and sigmoid (n=6) colon, and rectum (n=5) by colonoscopy. The sensitivity, specificity and accuracy of ultrasound to detect colorectal polyps were 47% (7/15, 95% confidence interval [CI] 21-73%), 100% (59/59, 95% CI 94-100%) and 89% (66/74, 95% CI 80-95%), respectively. The volume (mean ± standard deviation) of polyps not detected by ultrasound was significantly smaller than that detected (270±380 mm³ vs. 4,600±3,900 mm³, P=0.0124). We observed a significant difference in the location between the polyps detected and not detected by ultrasound (rectal/non-rectal=0/7 vs. 5/3, P=0.0256). No significant age or gender difference was observed.

CONCLUSION

The accuracy for detecting colorectal polyps by ultrasound was 89% (95% CI, 80-95%) in our cohort. Polyps found in the rectum and relatively smaller polyps accounted for several false-negative cases.

Chromoendoscopy Plus Mucosal Resection Versus Conventional Electrocoagulation for Intestinal Polyps in Children: Two Case Series

BACKGROUND

Conventional high-frequency electrocoagulation (HFEC) of intestinal polyps may be difficult in children and endoscopic mucosal resection (EMR) could be a less invasive option. Chromoendoscopy improves tissue localization during endoscopy, but its exact influence on the outcomes of children with intestinal lesions is still unknown.

AIMS

To analyze a series of children treated with EMR or HFEC and assess the value of chromoendoscopy.

METHODS

This was a retrospective analysis of two case series of patients treated at the Gastroenterology Department of the Guiyang Children's Hospital between February 2014 and November 2016. The children underwent EMR (n = 34) or conventional HFEC (n = 120). Demographic, clinical, and perioperative data were analyzed.

RESULTS

The polyps were larger in the HFEC group [median, 3.9 (0.1-27.0) versus 1.3 (0.03-64.0) mm, P = .03]. There was a higher frequency of multiple polyps in the EMR group (50.0% versus 15.1%, P < .001). Operation time and intraoperative bleeding were similar between the two groups (both P > .05). Hospital stay was longer with EMR than with HFEC [median, 5 (3-12) versus 4 (2-14) days, P = .02]. There was no intestinal perforation in either group. Postoperative bleeding amount was similar in both groups (P = .73). In the EMR group, 19 patients were operated using chromoendoscopy, whereas only 2 patients in the HFEC group were operated.

CONCLUSION

EMR could be appropriate for the treatment of intestinal polyps in children.

Colonic polyps and polyposis syndromes in pediatric patients

PURPOSE OF REVIEW

Gastrointestinal polyps are commonly encountered during childhood and are one of the most common causes of rectal bleeding in this age group. Most polyps are benign and located in the colon, with the most frequent type being juvenile polyps. However, in older pediatric patients, if multiple polyps are present, in patients who have a positive family history, or if polyps are located outside of the colon, either adenomatous polyps or polyps associated with genetic abnormalities are more common.

RECENT FINDINGS

Imaging techniques such as ultrasound and computed tomographic colonoscopy have recently been utilized to identify simple juvenile colonic polyps in children with rectal bleeding in whom there is a high index of suspicion. Colonoscopy with polypectomy is still required for histologic evaluation and resection of the polyp. There have been significant advances in genetic testing and management of hereditary gastrointestinal cancer syndromes with onset in childhood or adolescence that may ultimately reduce long-term morbidity and mortality. In addition to enhanced gastrointestinal and extraintestinal malignancy screening for affected individuals, specific gene mutations within a given condition such as adenomatous polyposis coli may predict clinical course and timing of specific interventions such as colectomy. In other conditions such as phosphatase and tensin homolog hamartoma tumor syndrome, phenotype may not be predicted by genotype.

SUMMARY

Pediatricians, pediatric gastroenterologists, and adult gastroenterologists caring for children should understand how to differentiate benign polyps in the pediatric age group from those associated with a higher risk of complications including recurrence risk and risk of development of intestinal or extraintestinal malignancy. Recent advances in genetic testing, as well as development of consensus guidelines, are key in the identification, screening, and follow-up of children and adolescents with polyposis syndromes.

Polyposis syndromes in children and adolescents: a case series data analysis

BACKGROUND

Polyposis syndromes in children are distinct entities clinically and pathologically. These syndromes have multiple genetic characteristics, with development of polyps at various sites of the gastrointestinal (GI) tract, and are associated with an increased risk of colon cancer. They are relatively rare, and have mostly been characterized in the adult population, whereas little epidemiologic data have been reported in children.

AIMS

The aim of this study was to summarize the pediatric experience collected over a period of 11 years on polyposis syndromes in three major Israeli tertiary centers.

PATIENTS AND METHODS

Medical records of children below 18 years old and their families, diagnosed with polyposis syndromes between 1999 and 2010, were reviewed. The data included disease presentation, genetic profile, surveillance, and treatment.

RESULTS

Fifty patients with polyposis syndromes were identified. The most frequent syndrome was familial adenomatous polyposis (FAP) in 33 children (66%), of whom 25 children (75.7%) had a known mutation. The mean age at presentation was 10.6±3.9 years (range 4-17 years). Most children were examined because of a family history of a polyposis syndrome (42 children, 84%). Among symptomatic children (32 children), the most frequent complaint was rectal bleeding (42%), followed by abdominal pain (22%), intussusception (10%), and diarrhea (4%). The youngest symptomatic patient was 4 years old at presentation, with rectal bleeding.All patients underwent multiple colonoscopies and upper GI endoscopies according to specific guidelines. Thirteen children underwent colonic surgery (39%); nine children had FAP. Adenocarcinoma of the colon was diagnosed in a 12.5-year-old child.

CONCLUSION

In this cohort study, FAP was the most common type of polyposis syndrome diagnosed in this pediatric population. Colon cancer was present at the onset of symptoms in a 12.5-year-old patient with FAP. We therefore recommend strict adherence to the hereditary GI cancer guidelines to prevent morbidity and mortality in FAP and other inherited polyposis syndromes.

An unusual case of pleuropulmonary blastoma in a child with jejunal hamartomas

We report a rare case of 9-month-old girl who presented with a choking episode and was found to have an incidental finding of a lung cyst and iron deficiency anemia leading to the diagnosis of pleuropulmonary blastoma (PPB) and a jejunal hamartoma. Our patient is the eighth that has been reported with the association of PPB with jejunal hamartoma and the first one in the radiological literature. PPB is the pulmonary analog of other dysontogenetic neoplasms in childhood. A biological sequence has been described with the three types of PPB to be interrelated as part of pathologic progression. PPB can be associated with other cysts and/or neoplasms in different organs. PPB is part of a hereditary neoplasia predisposition syndrome in up to 40% of cases. Mutations in DICER gene have been described with PPB. Hence, a pediatric patient diagnosed with PPB should be screened for associated conditions during childhood and adolescence including intestinal polyps. Obtaining family history for other neoplasms or cysts is important information that should raise the possibility of PPB in pediatric patients with cystic lung lesions. The presence of this syndrome should alert the clinician to screen and follow up patients and their relatives.

Different clinical manifestations between primary gastrointestinal malignancies and benign tumors in children

OBJECTIVE

The purpose of the present study was to review the different clinical manifestations of primary gastrointestinal (GI) malignancies and benign tumors in pediatric patients.

METHODS

The demographic data, duration to diagnosis, clinical features, laboratory data, location and pathology of the tumors, and outcomes of pediatric patients from January 1984 to December 2009 were retrospectively reviewed.

RESULTS

A total of 24 GI malignancies and 62 benign tumors were diagnosed. Patients in the benign group were mostly diagnosed in the first decade of life (73%), whereas majority of patients with malignancies were older than 10 years (79%). The most common tumor location in the benign group was the colorectum, whereas in the malignant group, tumors were distributed equally in the small intestine and colorectum. The median duration from onset to diagnosis in the benign group was longer than that of the malignant group (P>00.05). There was statistically significant increase in the presence of hematochezia in patients with benign tumor compared with those with malignancy (P<00.05). Among the malignancies, 79% presented with abdominal pain, followed by weight loss (25%), anorexia (25%), palpable mass (25%), and fever (21%), with statistically significant differences compared with the benign group (P<00.05). Anemia was found in 47% to 63% of patients in both groups (P>00.05). Two patients with polyposis subsequently developed malignancy.

CONCLUSIONS

Different manifestations of GI malignancies and benign tumors may help pediatricians to detect these early. Patients with polyposis should be aware of the risk of malignant change.

Management of colorectal carcinoma in children and young adults

Colorectal Carcinoma (CRC) is rare in patients less than 20 years of age. Although presenting symptoms are similar to adults, this diagnosis is rarely considered in the initial differential diagnosis of young patients. We will review what is published about the incidence, epidemiology, and clinical presentation of CRC in children, adolescents and young adults. Because of its rarity in this age group, few pediatric oncologists will have experience with CRC, and clinical trials will rarely be available. The treatment of CRC in adults is evolving rapidly and consultation with medical oncologists experience in treating adults with CRC is essential to develop the best treatment plan for a young patient diagnosed with CRC.

Colorectal polyps: a frequently-missed cause of rectal bleeding in Egyptian children

OBJECTIVES

Colorectal polyps are important causes of rectal bleeding but they have been infrequently reported in Egyptian children. The prevalence and characteristics of colorectal polyps in a consecutive cohort of Egyptian children with rectal bleeding are presented.

METHODS

A total of 174 children aged 2-12 years [mean (SD) 6.4 (3.7)] with fresh rectal bleeding were enrolled prospectively. Rectal examination, laboratory investigations and fibre-optic colonoscopy were performed in all patients.

RESULTS

The source of bleeding was diagnosed as colorectal polyps in 100 patients (57.4%) and was owing to other causes in 74. The interval between onset of symptoms and presentation ranged from 2 to 48 months [mean (SD) 18.3 (16)]. In patients with other causes, rectal bleeding was attributed to intestinal amoebiasis (42), diarrhoea/dysentery (18), severe constipation (2) and intestinal schistosomiasis (2). Polyps were solitary in 56 children (56%) and ranged from 2 to 5 in 34 (34%) and >5 in 10 (10%). Polyps were confined to the rectum in 68 children, were rectosigmoid in 20, in the descending colon in 8, and splenic flexure in 4. Polyps were juvenile in 84 children (84%), inflammatory in 10 (10%) and hyperplastic, schistosomal or adenomatous in 2 each (6%). Colonoscopic polypectomy was successful and arrested the bleeding in all cases.

CONCLUSION

In Egyptian children, colorectal polyps are relatively common and an easily treatable cause of fresh rectal bleeding. They should be high on the list of differential diagnoses.

Familial adenomatous polyposis in children and adolescents

BACKGROUND

Familial adenomatous polyposis (FAP) is the most common inherited polyposis syndrome characterized by the development of hundreds of colorectal adenomatous polyps. The aim of this study was to review cases of FAP diagnosed at The Children's Hospital of Philadelphia in a 16-year period.

METHODS

Medical records of patients diagnosed as having FAP between 1990 and 2005 were reviewed. The collected data included disease presentation, genetic profile, extraintestinal manifestations, surveillance, and treatment.

RESULTS

We identified 12 patients with FAP. The age range at presentation was 7 to 18 years. Seven (68%) patients presented due to symptoms, the most common of which was rectal bleeding (6 patients, 86%). The youngest age at which polyps were detected was 7 years. Eight patients (67%) had positive family history. Three patients had Gardner syndrome and 1 presented in infancy with hepatoblastoma. Four patients had adenomatous polyposis coli gene mutation identified. One patient was diagnosed as having rectal carcinoma in situ. Six patients (50%) had gastric fundic gland polyposis and 6 had duodenal adenomatous changes. Capsule endoscopy was performed in 3 patients; 1 had multiple polyps in the duodenum and the jejunum. Seven patients (58%) underwent total colectomy with no serious complications.

CONCLUSIONS

FAP is a rare condition but with significant risk of cancer and comorbidity. In this series, patients commonly presented to medical attention due to their symptoms. The youngest patient with polyps detected was 7 years old. We identified 1 patient with rectal cancer in situ and high proportion of patients with duodenal adenomatous lesions. Majority of patients underwent early colectomy.

Utility of fecal lactoferrin in identifying Crohn disease activity in children

OBJECTIVES

Fecal lactoferrin (FL) is a noninvasive biomarker that is elevated in Crohn disease (CD) compared to irritable bowel syndrome. The purpose of this study was to evaluate FL in identifying children with active versus inactive CD.

PATIENTS AND METHODS

Fresh stool samples were collected from children with CD scheduled for endoscopy or a clinic visit, and from new outpatients who were scheduled for colonoscopy. FL was determined using a polyclonal antibody-based enzyme-linked immunosorbent assay. Physical global assessment, endoscopic findings, erythrocyte sedimentation rate (ESR), and the Pediatric CD Activity Index (PCDAI) were recorded for patients with CD. The PCDAI scores symptoms, laboratory parameters, physical examination, and extraintestinal manifestations. A score of ≤10 is inactive disease, 11 to 30 is mild active, and ≤31 is moderate to severe active.

RESULTS

Of 101 study patients (4- to 20-year-old, 66 boys), 31 had active CD, 23 had inactive CD, and 37 had noninflammatory bowel disease (non-IBD) conditions. Four patients with ulcerative colitis and 6 patients with polyposis were excluded from analysis. FL was significantly elevated in CD versus non-IBD (P < 0.001) and in active versus inactive CD (P < 0.001). The PCDAI and ESR were higher in active CD than in inactive CD (both P < 0.001). Using an FL cutoff of 7.25 μg/g, FL has 100% sensitivity and 100% negative predictive value in detecting active CD. Using an FL cutoff level of 60 μg/g, FL had 84% sensitivity, 74% specificity, 81% positive predictive value, and 77% negative predictive value for detecting active CD.

CONCLUSIONS

FL is a promising biomarker of active CD and may be more practical to use when it is not feasible to obtain all of the necessary clinical information for the PCDAI.

Gastrointestinal polyps in children

BACKGROUND

Gastrointestinal polyps are common in children. The purpose of this study was to review the clinical manifestations, diagnostic procedures, endoscopic findings, management, pathology, and recurrence of gastrointestinal polyps in children at Mackay Memorial Hospital.

METHODS

We retrospectively reviewed the charts of 50 children with a diagnosis of gastrointestinal polyps managed at Mackay Memorial Hospital between January 1984 and April 2007. Demographic data; clinical features; polyp size, number and location; endoscopic findings; management; pathology; and information on recurrences were extracted from the clinical records.

RESULTS

The distribution of polyps in the 50 patients included gastric (4 patients), duodenal (2), ileocecal (4) and colorectal polyps (40). All patients with gastric polyps presented with vomiting, and three of the four patients with ileocecal polyps presented with intussusception. The mean age of the 40 patients with colorectal polyps was 6.8 years. The majority of those polyps were in the rectosigmoid colon; 36 patients presented with hematochezia. Solitary polyps were identified in 33 patients and multiple polyps were identified in seven patients. Most of the colorectal polyps were less than 2cm in diameter. Histologically, the most frequent type was juvenile polyp.

CONCLUSION

Gastrointestinal polyps in children are usually benign. Pediatricians treating a child with a gastrointestinal polyp should pay attention to the immediate complications of the polyps, such as intussusception or bleeding, the extraintestinal manifestations and long-term risk for malignancy.

Randomised controlled trial of paediatric magnetic positioning device assisted colonoscopy: a pilot and feasibility study

BACKGROUND AND AIMS

Complete colonoscopy is critical for the evaluation of many paediatric gastrointestinal diseases. The aim of the study was to investigate the feasibility of magnetic positioning device for paediatric colonoscopy and to compare completion rate and procedure time with and without the device.

METHODS

Prospective randomised controlled trial of standard colonoscopy compared to magnetic positioning device assisted colonoscopy in children and adolescents ages 7-20 years was performed.

RESULTS

Analysis showed that the proportion of successfully completed colonoscopies were 19/20 (95%) in the MP arm versus 17/18 (94.4%) in the SC arm, p=NS. The median time to complete colonoscopy to the cecum was 16.5 min (range 6-52 min) in the MP arm and 12 min (range 6-33 min) in the SC arm, p=NS.

CONCLUSIONS

Our preliminary data suggest that the use of magnetic positioning device for colonoscopy is feasible in paediatric patients. These data suggest that the use of magnetic positioning device may not be of benefit for experienced endoscopists who achieved very high colonoscopy completion rates without the MP device. Further studies are needed to determine its role in paediatric colonoscopy since this device may be of more benefit for physicians in training.

Epidemiology and management options for colorectal cancer in children

Colorectal carcinoma (CRC), although primarily a disease of adulthood, accounts for 2% of malignancies in adolescents and has been reported in children as young as 9 months of age. Our knowledge of CRC in pediatrics is based on a handful of case series and case reports. Apart from one small clinical trial, there has been a lack of prospective clinical studies in this age group. Based on these published reports, most CRC in children is sporadic, but it can also arise in the setting of predisposing conditions, such as gastrointestinal polyposis syndromes, nonpolyposis familial cancer syndromes, and inflammatory bowel disease. Despite some similarities to adult disease, CRC in childhood may be intrinsically different biologically, because it differs from adult-onset CRC in several respects. Childhood CRC tends to be diagnosed at an advanced stage, is largely of mucinous histology, and (probably because of these features) tends to have a poorer outcome. As a result of its rarity in children and the lack of prospective pediatric studies, recommendations for therapy are primarily extrapolated from adult clinical trials. A review of pediatric case series in the English literature emphasizes the prognostic significance of stage of disease, as well as extent of surgical resection. As in adults, early detection is critical in an effort to capture the disease at less advanced stages. Complete surgical resection with aggressive lymph node dissection is essential for cure, and neoadjuvant chemotherapy may be used in an effort to render unresectable lesions resectable. Active agents in adults with CRC include fluorouracil, folinic acid (leucovorin), oxaliplatin, and irinotecan. Furthermore, newer targeted therapeutic agents, such as bevacizumab and cetuximab, have added additional efficacy to the standard chemotherapy backbone. Collaborative multi-institutional pediatric clinical trials are needed to evaluate the prognosis, optimal treatment response, and the basic biology of childhood onset CRC.

Sonographic diagnosis of intestinal polyps in children

Although colonoscopy is the modality of choice for the diagnosis of intestinal polyps, sonography may be the first diagnostic modality in the evaluation of children with this pathology. Graded compression sonography of the small and large bowel may be useful in diagnosing intestinal polyps. A specific diagnosis is possible in many cases as most polyps have a characteristic appearance. Although sonography is not intended to replace endoscopy in the diagnostic work-up of intestinal polyps, it is important for radiologists to be aware of this appearance as they can be the first in making the diagnosis of intestinal polyps using sonography.

Colonic polyps in children and adolescents

Colonic polyps most commonly present with rectal bleeding in children. The isolated juvenile polyp is the most frequent kind of polyp identified in children. 'Juvenile' refers to the histological type of polyp and not the age of onset of the polyp. Adolescents and adults with multiple juvenile polyps are at a significant risk of intestinal cancer. The challenge for adult and pediatric gastroenterologists is determining the precise risk of colorectal cancer in patients with juvenile polyposis syndrome. Attenuated familial adenamatous polyposis (AFAP) can occur either by a mutation at the extreme ends of the adenomatous polyposis coli gene or by biallelic mutations in the mutY homologue (MYH) gene. The identification of MYH-associated polyposis as an autosomal recessive condition has important implications for screening and management strategies. Adult and pediatric gastroenterologists need to be aware of the underlying inheritance patterns of polyposis syndromes so that patients and their families can be adequately evaluated and managed. Colonic polyps, including isolated juvenile polyps, juvenile polyposis syndrome, FAP, AFAP and MYH-associated polyposis, are discussed in the present review.

Café au lait macules and juvénile polyps

Several hereditary and nonhereditary gastrointestinal tract polyposis syndromes exhibit extra-intestinal manifestations, including cutaneous findings. However, a lack of information exists regarding cutaneous features of juvenile polyposis. Our objective was to document the prevalence of cutaneous hyperpigmented lesions in children with juvenile polyposis coli or juvenile polyposis coli and their first degree relatives.Children seen in the gastroenterology practice at The Children's Hospital in Denver, Colorado with polyps (juvenile polyposis coli, sporadic juvenile polyps, and familial adenomatous polyposis coli) and their first degree relatives were invited to participate in the study. A comprehensive skin examination was performed on those who consented to participate. We found that 8 of 14 patients (eight with juvenile polyposis coli, four with juvenile polyposis, and two with familial adenomatous polyposis coli) had at least one café-au-lait macule, compared with three of 27 relatives (p=0.003).The prevalence of at least one café-au-lait macule in our patients (8/14 or 57.1%, CI: 28.9–82.3%) was significantly higher than the general population prevalence of 28.5% (p=0.023). However, if the two patients with familial adenomatous polyposis coli were excluded, the comparison with the general population prevalence did not reach statistical significance (p=0.095). The prevalence of multiple cafe´-au-lait macules in our patients (4/14 or 28.6%; CI:8.4–58.1%) was significantly higher than the general population prevalence of 5.2% (p ¼ 0.005). A notable finding was the presence of multiple café -au-lait macules in 4 of 12 juvenile polyposis coli/juvenile polyposis patients.Two patients with juvenile polyposis coli also had lentigines. In this selected case series, we observed single or multiple café-au-lait macules in a high proportion of children with the three types of polyps. Further studies are needed to assess a possible common pathway for hamartomatous polypsand café-au-lait macules.

Juvenile Polyp in Thai Children—Clinical and Colonoscopic Presentation

BACKGROUND

The aim of this prospective study was to describe the clinical characteristics of colorectal polyp in Thai children.

METHODS

From December 2002 to February 2005, children under 15 years of age presenting with rectal bleeding were prospectively enrolled. Demographic, clinical, and laboratory information was recorded. Location, number, characteristics, and histopathology of the polyps were noted.

RESULTS

There were 32 patients with a mean age of 6.5 years. The most common presenting symptom was hematochezia, followed by prolapsing rectal mass and diarrhea. In 20 patients there was a single polyp, 6 had 2-4 polyps, and 6 were diagnosed with polyposis coli. Most of the polyps were located exclusively at the rectum and sigmoid colon. In only 7 cases were the polyps proximal to the rectosigmoid region. This included 6 patients who had polyps beyond the splenic flexure. All were juvenile polyps without evidence of adenomatous changes. Compared to those with isolated polyps, the patients with polyposis coli had a statistically significant incidence of right-sided polyps (P <0.001) and a history of prolapse of the rectal mass (P = 0.006).

CONCLUSIONS

Because of the high prevalence of right-sided polyps and the concern about malignant transformation, colonoscopy should be considered as the initial evaluation in children with rectal bleeding.

Genetic predisposition to colorectal cancer: new pieces in the pediatric puzzle

Colorectal cancer is rare in childhood. The 2 best characterized familial syndromes, hereditary nonpolyposis colorectal cancer (HNPCC, Lynch syndrome) and familial adenomatous polyposis (FAP), are autosomal dominant inherited disorders. HNPCC is relevant to pediatric gastroenterology practice because children and adolescents with underlying colorectal cancer can have germ-line mutations of mismatch repair genes. Recent attention has focused on characterizing genetic predisposition to attenuated FAP in individuals who do not have germ-line mutations in the APC gene. The identification of a second mechanistic explanation called MYH-associated polyposis (MAP), which is an autosomal-recessive condition, has important implications for both screening and management strategies. Hereditary colorectal cancer including HNPCC, FAP, attenuated FAP and MYH-associated polyposis in children are the subject of this review.

Cowden syndrome: report of two cases and review of clinical presentation and management of a rare colorectal polyposis

BACKGROUND/AIMS

Cowden syndrome (CS) is a rare and complex disease inherited through an autosomal dominant trait associated with germline mutations of the PTEN gene.

OBJECTIVE

This article reports 2 female patients with classic features of the syndrome and reviews the current guidelines regarding diagnosis and surveillance.

REVIEW

Although it exhibits variable clinical expressivity, the diagnosis is based on characteristic mucocutaneous alterations such as multiple facial trichilemmomas, oral mucosal papillomatosis, and acral and palmoplantar keratoses. These manifestations often precede systemic involvement. Extracutaneous lesions include fibrocystic disease of the breast, thyroid goiters or adenomas, multiple polyposis of the gastrointestinal tract, and ovarian cysts. Gastrointestinal polyps are usually asymptomatic, and the risk of gastrointestinal cancer is not greatly increased. Otherwise, an important feature of Cowden's disease is the greater risk of breast and thyroid cancer.

CONCLUSIONS

Because of the potentially serious associations with internal malignancy, early and accurate diagnosis of CS is essential. For this reason, all patients must be screened for occult malignancies and undergo close surveillance throughout lifetime.

Effect of Helicobacter pylori eradication on gastric hyperplastic polyposis in Cowden’s disease

A 21-year-old woman with complaints of hematochezia was diagnosed as having Cowden’s disease (CD), an autosomal dominant condition characterized by multiple hamartomas, since facial papules and gingival papillomas were identified. On endoscopy, multiple hyperplastic polyps were seen in the rectum and left-side colon. There were also esophageal glycogenic acanthosis and hyperplastic polyposis in the antrum accompanied by Helicobacter pylori-related gastritis. Although gastric hyperplastic polyposis had by no means regressed with unsuccessful first-line eradication therapy for H pylori, following cure of the infection with salvage therapy consisting of rabeprazole, amoxicillin and metronidazole, the polyposis lesions almost disappeared. Follow-up gastroscopy 2 and 3 years after cessation of the second-line eradication therapy revealed almost complete regression of the polyposis lesions with no evidence of H pylori infection. We recommend eradication treatment for CD patients with gastric hyperplastic polyps and the infection, as the occurrence of gastric carcinoma among hyperplastic polyps has been described.

Gastrointestinal polyposis in childhood: clinicopathologic and genetic features

Gastrointestinal polyps and certain extraintestinal lesions in children may herald a hereditary polyposis syndrome, with an increased risk of neoplasia and other health problems for both children and their relatives. The availability of molecular/genetic screening tests has increased early diagnosis of younger members of known polyposis families. This article reviews the gross and microscopic features of polyposis syndromes of childhood and summarizes the molecular/genetic advances in this field. Clinical management is also briefly discussed.

Pediatric oral medicine

A thorough examination of the oral mucosa can provide helpful clues toward making a diagnosis in a number of developmental, neoplastic, inflammatory, and infectious conditions. A number of oral lesions seen in infants and children are benign and of no medical significance. In these instances, the ability of the physician to confidently identify the diagnosis, and reassure parents that a lesion is not worrisome, carries significant value. Likewise, the ability to recognize an underlying systemic illness or genetic disease based on an oral examination can also be of tremendous value, particularly when oral involvement is the presenting feature.

Gastrointestinal polyps and polyposis syndromes in children

Gastrointestinal polyps are common during childhood and most often present with painless rectal bleeding. Most polyps occur as isolated colonic lesions and are not harbingers of an underlying genetic disorder, nor do they bestow a risk of gastrointestinal cancer. The astute pediatrician must be aware, however, that occasionally polyps may occur in the context of a genetic polyposis disorder characterized by an increase in the life-time risk of cancer in the gastrointestinal tract and other organ systems. This review outlines the major polyposis syndromes affecting children and highlights associated findings that might clue the alert physician to an underlying diagnosis. Recent developments in the understanding of the genetics of each disorder are emphasized.