GI polyposis and glycogenic acanthosis of the esophagus associated with PTEN mutation positive Cowden syndrome in the absence of cutaneous manifestations

Clinical Guidelines for Diagnosis and Management of Cowden Syndrome/PTEN Hamartoma Tumor Syndrome in Children and Adults-Secondary Publication

Cowden syndrome (CS)/PTEN hamartoma tumor syndrome (PHTS) is a rare autosomal dominantly inherited condition caused by germline pathogenesis. It is associated with multiple hamartomatous lesions occurring in various organs and tissues, including the gastrointestinal tract, skin, mucous membranes, breast, thyroid, endometrium, and brain. Macrocephaly or multiple characteristic mucocutaneous lesions commonly develop in individuals in their 20s. This syndrome is occasionally diagnosed in childhood due to the occurrence of multiple gastrointestinal polyps, autism spectrum disorders, and intellectual disability. CS/PHTS can be diagnosed taking the opportunity of multigene panel testing in patients with cancer. Appropriate surveillance for early diagnosis of associated cancers is required because patients have a high risk of cancers including breast, thyroid, colorectal, endometrial, and renal cancers. Under these circumstances, there is growing concern regarding the management of CS/PHTS in Japan, but there are no available practice guidelines. To address this situation, the guideline committee, which included specialists from multiple academic societies, was organized by the Research Group on Rare and Intractable Diseases granted by the Ministry of Health, Labour, and Welfare, Japan. The present clinical guidelines explain the principles in the diagnosis and management of CS/PHTS, together with four clinical questions and the corresponding recommendations, incorporating the concept of the Grading of Recommendations Assessment, Development, and Evaluation system. Herein, we present an English version of the guideline, some of which have been updated, to promote seamless implementation of accurate diagnosis and appropriate management of pediatric, adolescent, and adult patients with CS/PHTS.

Benign goiters requiring thyroidectomy as the signal for PTEN hamartoma tumor syndrome diagnosis

PTEN hamartoma tumor syndrome (PHTS) is a rare genetic cancer and tumor predisposition syndrome. Due to the wide spectrum of clinical manifestations and variable age at onset, the pathways leading to a PHTS diagnosis are difficult and highly variable. Many patients were found to have PHTS after a cancer diagnosis, missing the opportunity of prevention or enhanced cancer screening. This retrospective study evaluated a PHTS cohort followed in a high-risk surveillance clinic in a comprehensive cancer institution. A significant portion of the patients (60.9%, 14/23) had at least one cancer diagnosis (average age 34.6 years at diagnosis). A significant portion (78.3%, 18/23) were affected with clinically significant goiters (age 27.9 years), and many (60.9%, 14/23) had partial or total thyroidectomy (age 27.1 years). The average age at goiter diagnosis or thyroidectomy is younger than a cancer diagnosis. In 12 individuals who were affected with clinically significant goiter and cancer, all cancers were diagnosed after the thyroid disease (6.3 years). As clinically significant thyroid nodules in childhood or early young adulthood are common in PHTS, but uncommon for general population, these early onset thyroid nodules may alert the clinician to initiate PHTS-targeted evaluation and genetic testing.

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.

PTEN hamartoma tumor syndrome in childhood and adolescence-a comprehensive review and presentation of the German pediatric guideline

Background

The PTEN hamartoma tumor syndrome (PHTS) encompasses several different syndromes, which are linked to an autosomal-dominant mutation of the tumor suppressor PTEN gene on chromosome 10. Loss of PTEN activity leads to an increased phosphorylation of different cell proteins, which may have an influence on growth, migration, and apoptosis. Excessive activity of the PI3K/AKT/mTOR pathway due to PTEN deficiency may lead to the development of benign and malignant tumors and overgrowth. Diagnosis of PHTS in childhood can be even more challenging than in adulthood because of a lack of well-defined diagnostic criteria. So far, there are no official recommendations for cancer surveillance in affected children and adolescents.

Main body

All individuals with PHTS are at high risk for tumor development and thus might benefit from cancer surveillance strategies. In childhood, macrocephaly may be the only evident symptom, but developmental delay, behavioral problems, dermatological features (e.g., penile freckling), vascular anomalies, lipoma, or enlarged perivascular spaces in cerebral magnetic resonance imaging (cMRI) may help to establish the diagnosis. Regular psychomotor assessment and assistance in subjects with neurological impairment play an important role in the management of affected children. Already in early childhood, affected patients bear a high risk to develop thyroid pathologies. For that reason, monitoring of thyroid morphology and function should be established right after diagnosis. We present a detailed description of affected organ systems, tools for initiation of molecular diagnostic and screening recommendations for patients < 18 years of age.

Conclusion

Affected families frequently experience a long way until the correct diagnosis for their child’s peculiarity is made. Even after diagnosis, it is not easy to find a physician who is familiar with this rare group of diseases. Because of a still-limited database, it is not easy to establish evidence-based (cancer) surveillance recommendations. The presented screening recommendation should thus be revised regularly according to the current state of knowledge.

Dots, lines, contours, and ends: An image-based review of esophageal pathology

•

Learning Point #1: Small ulcers on esophagography are usually attributable to herpes esophagitis and drug-induced esophagitis. Although rare, Crohn’s disease may produce small apthoid ulcers. Large ulcers are usually attributable to CMV or HIV esophagitis.

•

Learning Point #2: The early findings of candida are plaques that mimic glycogenic acanthosis. When plaques are seen, consider early candida or glycogenic acanthosis. When shaggy esophagus is identified, consider candidiasis.

•

Learning Point #3: Varices and varicoid esophageal carcinoma may appear similar on imaging. The presence of obstruction and lack of change with time and position should sway the Radiologist to diagnosing varicoid esophageal carcinoma.

•

Learning Point #4: Transverse esophageal lines should suggest the entities of feline esophagus and idiopathic eosinophilic esophagitis.

•

Learning Point #5: Esophageal contour abnormalities may suggest extrinsic or intrinsic lesions. Extrinsic lesions include aberrant vessels. Intrinsic lesions include intramural pseudodiverticulosis, gastroesophageal reflux, Barrett’s esophagus, and esophageal cancer.

Esophageal pathologies encountered on fluoroscopic examination may pose a diagnostic challenge to the interpreting Radiologist. Understanding the varied imaging appearances of esophageal pathology requires a thorough understanding of barium esophagography. This article reviews the various fluoroscopic imaging findings of different esophageal pathologies by describing an approach to image interpretation centered on dots, lines, contours, and ends. By utilizing this approach, the Radiologist will be better positioned to reconcile seemingly disparate pathologies into a cogent and succinct differential diagnosis.

Revised Danish guidelines for the cancer surveillance of patients with Cowden Syndrome

INTRODUCTION

Cowden syndrome is a cancer predisposition syndrome caused by pathogenic variants in PTEN. The affected patients possess an increased risk of breast, thyroid, renal, colorectal, endometrial cancers as well as malignant melanoma. Thus prophylactic surveillance and follow up is crucial for these patients.

METHODS

A review of the literature including existing guidelines from the years 1996 until 2017 was carried out. In total, 2078 scientific papers were identified through database searches on Cowden syndrome. Among these, 11 manuscripts were included based on scientific relevance and quality. Expert consensus was reached to define management guidelines.

RESULTS

The literature revealed a high risk of cancer in specific organs for patients diagnosed with Cowden Syndrome. Alternative management guidelines were proposed and discussed.

CONCLUSIONS

Here we propose a revised set of management guidelines for patients with Cowden syndrome in Denmark to address the increased risk of various cancer types.

Spectrum of gastrointestinal tract pathology in a multicenter cohort of 43 Cowden syndrome patients

Most patients with Cowden syndrome have lesions in the gastrointestinal tract, characterized by multiple polyps of various histologic types in the large bowel, polyps in the upper gastrointestinal tract, and esophageal glycogenic acanthosis. However, pathologists are often unaware of the distinctive polyposis phenotype of Cowden syndrome. In this multicenter study, we report the spectrum of gastrointestinal manifestations in a series of 43 Cowden syndrome patients who had at least one endoscopy. The median age at the first endoscopy was 46 years and 58% were women. In 24 of 29 (83%) tested patients, a pathogenic germline mutation in PTEN was identified. The histology from 199 endoscopy procedures (67 upper gastrointestinal endoscopy and 132 colonoscopies) was reviewed. Hamartomatous polyps of the large bowel were the most common lesions, present in 85% of patients. Hamartomatous polyps showed varied histology, including lymphoid aggregates in 55% of patients, a lipomatous component in 52%, a ganglioneuromatous component in 52%, and a fibrous-rich component in 14%. Polyps with at least two different stromal components were found in 55% of patients. Inflammatory polyps were present in 21% of patients. Conventional adenomas and serrated polyps were identified in 48% and 62% of patients, respectively. In the upper gastrointestinal tract, the most common lesions were esophageal glycogenic acanthosis (37%), gastric hamartomatous polyps (47%), and duodenal hamartomatous polyps (20%). All patients with glycogenic acanthosis who had a colonoscopy had hamartomatous polyps of the large bowel. In five patients, the diagnosis of Cowden syndrome was established after the pathology report raised suspicion for the diagnosis. Pathologists who are aware of the characteristic admixture of lesions in Cowden syndrome can play an essential role in recommending referral to genetic counseling and gene testing. Early diagnosis of Cowden syndrome is important, as these patients and their relatives are at increased risk for developing multiple cancers.

PTEN Hamartoma tumor syndrome in childhood: A review of the clinical literature

PTEN hamartoma tumor syndrome (PHTS) is a highly variable autosomal dominant condition associated with intellectual disability, overgrowth, and tumor predisposition phenotypes, which often overlap. PHTS incorporates a number of historical clinical presentations including Bannayan-Riley-Ruvalcaba syndrome, Cowden syndrome, and a macrocephaly-autism/developmental delay syndrome. Many reviews in the literature focus on PHTS as an adult hamartoma and malignancy predisposition condition. Here, we review the current literature with a focus on pediatric presentations. The review starts with a summary of the main conditions encompassed within PHTS. We then discuss PHTS diagnostic criteria, and clinical features. We briefly address rarer PTEN associations, and the possible role of mTOR inhibitors in treatment. We acknowledge the limited understanding of the natural history of childhood-onset PHTS as a cancer predisposition syndrome and present a summary of important management considerations.

The Clinical Spectrum of PTEN Mutations

PTEN is a tumor suppressor gene that classically dampens the PI3K/AKT/mTOR growth-promoting signaling cascade. PTEN dysfunction causes dysregulation of this and other pathways, resulting in overgrowth. Cowden syndrome, a hereditary cancer predisposition and overgrowth disorder, was the first Mendelian condition associated with germline PTEN mutations. Since then, significant advances by the research and medical communities have elucidated how clinical phenotypic manifestations result from the underlying germline PTEN mutations. With time, it became evident that PTEN mutations can result in a broad phenotypic spectrum, causing seemingly disparate disorders from cancer to autism. Hence, the umbrella term of PTEN hamartoma tumor syndrome (PHTS) was coined. Timely diagnosis and understanding the natural history of PHTS are vital because early recognition enables gene-informed management, particularly as related to high-risk cancer surveillance and addressing the neurodevelopmental symptoms.

Clinical, Imaging, and Pathologic Features of Conditions with Combined Esophageal and Cutaneous Manifestations

A variety of clinically significant conditions can affect both the esophagus and the skin. Esophageal and cutaneous manifestations may directly reflect the underlying disease process, as in infections such as herpes simplex virus, bullous diseases such as epidermolysis bullosa and mucous membrane pemphigoid, connective tissue diseases such as systemic sclerosis, and inflammatory diseases such as lichen planus. Alternatively, esophageal and cutaneous findings may result from conditions that are closely associated with and potentially pathognomonic for but distinct from the underlying disease process, as in genetic diseases such as Cowden syndrome or paraneoplastic syndromes such as acrokeratosis paraneoplastica. Other diseases such as Crohn disease may have cutaneous manifestations that directly reflect the same underlying inflammatory process that affects the gastrointestinal tract or cutaneous manifestations that represent reactive or associated conditions distinct from the underlying inflammatory process. The cutaneous manifestations of disease may precede, coincide with, or follow the esophageal manifestations of disease. The authors present the characteristic clinical features and imaging findings associated with common and uncommon conditions that have esophageal and cutaneous manifestations. Each condition is presented with a brief overview, discussion of salient clinical and cutaneous manifestations, and description of the typical esophageal imaging findings, with particular attention to implications for diagnosis, prognosis, and treatment. Recognition of potential associations between cutaneous lesions and esophageal imaging findings is important for establishing a specific diagnosis or generating a meaningful differential diagnosis.

PTEN Hamartoma Tumor Syndrome: A Clinical Overview

The phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) is a grouping of related genetic disorders that has been linked to germline mutations in the PTEN gene. These disorders include Cowden syndrome (CS), Bannayan–Riley–Ruvalcaba syndrome, adult Lhermitte–Duclos disease, and autism spectrum disorders associated with macrocephaly. The majority of the clinical information available on PHTS, however, is related to individuals diagnosed with CS. There is still much to be learned about this disorder, since diagnostic criteria for CS were only established in 1996, before the identification of the PTEN gene, and were based primarily on features seen in cases reported in the existing literature. More recently, however, data from several large series of patients have shown that a number of the clinical features associated with PTEN mutations are either more or less common than previously reported. In addition, we now know that only about 30–35% of patients meeting clinical diagnostic criteria for Cowden syndrome actually have a detectable PTEN mutation. Thus, our understanding of PTEN-related diseases and their management has evolved significantly over time. The United States National Comprehensive Cancer Network (NCCN) has produced and regularly updates practice guidelines which include clinical diagnostic criteria as well as guidelines for PTEN testing and management of patients with mutations. This review will summarize the overall literature on PHTS as well as recent findings which are broadening our understanding of this set of disorders.

65 YEARS OF THE DOUBLE HELIX: One gene, many endocrine and metabolic syndromes: PTEN-opathies and precision medicine

An average of 10% of all cancers (range 1-40%) are caused by heritable mutations and over the years have become powerful models for precision medicine practice. Furthermore, such cancer predisposition genes for seemingly rare syndromes have turned out to help explain mechanisms of sporadic carcinogenesis and often inform normal development. The tumor suppressor PTEN encodes a ubiquitously expressed phosphatase that counteracts the PI3K/AKT/mTOR cascade - one of the most critical growth-promoting signaling pathways. Clinically, individuals with germline PTEN mutations have diverse phenotypes and fall under the umbrella term PTEN hamartoma tumor syndrome (PHTS). PHTS encompasses four clinically distinct allelic overgrowth syndromes, namely Cowden, Bannayan-Riley-Ruvalcaba, Proteus and Proteus-like syndromes. Relatedly, mutations in other genes encoding components of the PI3K/AKT/mTOR pathway downstream of PTEN also predispose patients to partially overlapping clinical manifestations, with similar effects as PTEN malfunction. We refer to these syndromes as 'PTEN-opathies.' As a tumor suppressor and key regulator of normal development, PTEN dysfunction can cause a spectrum of phenotypes including benign overgrowths, malignancies, metabolic and neurodevelopmental disorders. Relevant to clinical practice, the identification of PTEN mutations in patients not only establishes a PHTS molecular diagnosis, but also informs on more accurate cancer risk assessment and medical management of those patients and affected family members. Importantly, timely diagnosis is key, as early recognition allows for preventative measures such as high-risk screening and surveillance even prior to cancer onset. This review highlights the translational impact that the discovery of PTEN has had on the diagnosis, management and treatment of PHTS.

Gastrointestinal Polyposis in Cowden Syndrome

GOALS

To further characterize the gastrointestinal manifestations of Cowden syndrome in clinically well-annotated patients to improve the diagnosis of this syndrome.

BACKGROUND

The gastrointestinal manifestations of Cowden Syndrome, an important heritable and multiorgan cancer syndrome, are not well defined. Proper diagnosis is essential for effective cancer surveillance and prevention in these patients.

STUDY

Cowden patients with gastrointestinal polyps were selected for medical record and pathologic slide review.

RESULTS

Of 19 total patients, genetic testing revealed pathogenic PTEN mutations in 12. Pan-colonic (11-patients, 58%) and pan-gastrointestinal (8-patients, 42%) polyp distributions were common. Inflammatory (juvenile) polyps were the most common of the hamartomatous polyp (18 patients, 95%), along with expansive lymphoid follicle polyps (12 patients, 63%), ganglioneuromatous polyps (10 patients, 53%), and intramucosal lipomas (5 patients, 26%). The findings of 2 or more hamartomatous polyp types per patient emerged as a newly described and highly prevalent (79%) feature of Cowden syndrome. Ganglioneuromatous polyps, rare in the general population, and intramucosal lipomas, which may be unique to Cowden syndrome, should both prompt further evaluation. Colonic adenomas and adenocarcinomas were common; 10 patients (53%) had single and 3 (16%) had ≥3 adenomas, whereas 2 (11%) had colonic adenocarcinoma, strengthening the emerging association of colorectal cancer with Cowden syndrome.

CONCLUSIONS

The clinical phenotypes and gastrointestinal manifestations in Cowden syndrome are quite variable but this series adds the following new considerations for this syndromic diagnosis: multiple gastrointestinal hamartomas, especially 2 or more hamartoma types, and any intramucosal lipomas or ganglioneuromas. These features should warrant consideration of Cowden syndrome.

Clinical Implications for Germline PTEN Spectrum Disorders

Patients with PTEN hamartoma tumor syndrome (PHTS) may present to a variety of different subspecialties with benign and malignant clinical features. They have increased lifetime risks of breast, endometrial, thyroid, renal, and colon cancers, as well as neurodevelopmental disorders such as autism spectrum disorder. Patients and affected family members can be offered gene-directed surveillance and management. Patients who are unaffected can be spared unnecessary investigations. With longitudinal follow-up, we are likely to identify other non-cancer manifestations associated with PHTS such as metabolic, immunologic, and neurologic features.

Gastrointestinal tract cancers: Genetics, heritability and germ line mutations

Gastrointestinal (GI) tract cancers that arise due to genetic mutations affect a large number of individuals worldwide. Even though many of the GI tract cancers arise sporadically, few of these GI tract cancers harboring a hereditary predisposition are now recognized and well characterized. These include Cowden syndrome, MUTYH-associated polyposis, hereditary pancreatic cancer, Lynch syndrome, Peutz-Jeghers syndrome, familial adenomatous polyposis (FAP), attenuated FAP, serrated polyposis syndrome, and hereditary gastric cancer. Molecular characterization of the genes that are involved in these syndromes was useful in the development of genetic testing for diagnosis and also facilitated understanding of the genetic basis of GI cancers. Current knowledge on the genetics of GI cancers with emphasis on heritability and germ line mutations forms the basis of the present review.

Cowden Syndrome Detected by FDG PET/CT in an Endometrial Cancer Patient

Cowden syndrome (CS) is a rare autosomal dominant disorder characterized by multiple hamartomas in various tissues and cancers (breast, thyroid, and endometrium). We report CS of the esophagus and gastrointestinal tract that was incidentally detected by positron emission tomography/computed tomography (PET/CT) at postoperative surveillance in an endometrial cancer patient. PET/CT showed mildly increased FDG uptake along the entire esophagus and stomach. Upper GI endoscopy and histologic examination revealed glycogenic acanthosis of the esophagus and several hundred gastric polyps. In our case, increased FDG uptake of the esophageal wall contributed to the diagnosis of CS.

ACG clinical guideline: Genetic testing and management of hereditary gastrointestinal cancer syndromes

This guideline presents recommendations for the management of patients with hereditary gastrointestinal cancer syndromes. The initial assessment is the collection of a family history of cancers and premalignant gastrointestinal conditions and should provide enough information to develop a preliminary determination of the risk of a familial predisposition to cancer. Age at diagnosis and lineage (maternal and/or paternal) should be documented for all diagnoses, especially in first- and second-degree relatives. When indicated, genetic testing for a germline mutation should be done on the most informative candidate(s) identified through the family history evaluation and/or tumor analysis to confirm a diagnosis and allow for predictive testing of at-risk relatives. Genetic testing should be conducted in the context of pre- and post-test genetic counseling to ensure the patient's informed decision making. Patients who meet clinical criteria for a syndrome as well as those with identified pathogenic germline mutations should receive appropriate surveillance measures in order to minimize their overall risk of developing syndrome-specific cancers. This guideline specifically discusses genetic testing and management of Lynch syndrome, familial adenomatous polyposis (FAP), attenuated familial adenomatous polyposis (AFAP), MUTYH-associated polyposis (MAP), Peutz-Jeghers syndrome, juvenile polyposis syndrome, Cowden syndrome, serrated (hyperplastic) polyposis syndrome, hereditary pancreatic cancer, and hereditary gastric cancer.

Cronkhite–Canada syndrome six decades on: the many faces of an enigmatic disease

Cronkhite–Canada syndrome is a rare gastro-enterocolopathy of uncertain aetiology first described almost 60 years ago. It is characterised by diffuse gastrointestinal polyposis sparing only the oesophagus, ectodermal abnormalities and an unpredictable but often fatal clinical course. The disease may demonstrate extremely diverse clinical and endoscopic features, which often leads to a delay in diagnosis. A high index of suspicion and recognition of the characteristic histological findings frequently facilitate a correct diagnosis, but the distribution of the gastrointestinal pathology and its microscopic features may be atypical. The pathologist thus requires a thorough knowledge of both the typical and many atypical faces of this disease, for which various documented therapies often still prove ineffective. Close correlation with clinical findings, including any pertinent ectodermal abnormalities, and careful examination of biopsies derived from polypoid and endoscopically spared mucosa will ensure a timely and correct diagnosis in patients with this enigmatic syndrome.

Increased prevalence of eosinophilic gastrointestinal disorders in pediatric PTEN hamartoma tumor syndromes

OBJECTIVES

The PTEN hamartoma tumor syndromes (PHTSs) are a collection of disorders caused by germline mutations of the tumor suppressor gene PTEN. Eosinophilic gastrointestinal disorders (EGIDs) are rare diseases characterized by food-induced, eosinophil-dominant inflammation in various segments of the gastrointestinal tract. On the basis of our clinical observations of several patients with EGID-PHTS, we investigated whether there is an association between these 2 disorders.

METHODS

The Cincinnati Children's Hospital Medical Center (CCHMC) Informatics for Integrating Biology and the Bedside (i2b2) warehouse was queried for the years 2007 to 2012 using International Classification of Diseases-9 codes for PTEN-related diseases; the results were cross-referenced with participants enrolled in the Cincinnati Center for Eosinophilic Disorder's EGID database to identify patients with both disorders. In an effort to replicate our findings, the Cleveland Clinic Genomic Medicine Institute PTEN database was queried for cases between 2005 and 2012. Inclusion criteria were age ≤ 18 years, history of PHTS, and an esophagogastroduodenoscopy (EGD) and/or colonoscopy with at least 1 histologic EGID diagnosis confirmed by a CCHMC pathologist. The Pearson χ(2) test was used to determine the odds of EGID enrichment in PHTS.

RESULTS

Of the 1,058,260 CCHMC distinct patients identified by the i2b2 search, 53 had clinical diagnoses suggestive of PHTS. Thirteen of the 53 had PTEN mutations, with 8 of 13 (62%) having had an EGD and/or colonoscopy. Five of the 8 had confirmed EGID. At the Cleveland Clinic, 3 of 75 patients (3/4 who had EGD and/or colonoscopy) with PHTS had confirmed EGID. CCHMC i2b2 query data showed a substantial enrichment of EGIDs in PHTSs (odds ratio  272; confidence interval 89-831, P < 0.0001). An EGID prevalence estimate from the i2b2 query supported a marked enrichment of EGIDs in PHTSs in the Cleveland Clinic database (P < 0.0001). Among the 8 subjects with EGIDs and PHTSs, the age at EGID and PHTS diagnosis was 7.6 ± 3.2 and 7.9 ± 5.8 years, respectively. Patients with EGID-PHTS had excess eosinophils in biopsies of the esophagus (75%), stomach (38%), and colon (13%), with a notable presence of eosinophil-rich gastrointestinal polyposis (88%).

CONCLUSIONS

EGID is a previously unrecognized comorbid disease in pediatric patients with PHTS. These data suggest a potential role of PTEN in contributing to EGID susceptibility.

[Cowden syndrome]

INTRODUCTION

Cowden syndrome is rare; oral symptoms are not always diagnosed. This case of Cowden syndrome was revealed by gingival hypertrophy.

OBSERVATION

A 21-year-old female patient consulted for gingival hypertrophy and multiple papules in the mouth. She had a history of thyroid lobectomy due to a goiter. The gingival papillomatosis and the goiter suggested a Cowden syndrome. The diagnosis was confirmed clinically by facial skin papules.

DISCUSSION

Cutaneous and oral lesions are usually the first symptoms of the syndrome. Diffuse gingival papillomatosis may suggest a Cowden syndrome and should lead to screen for associated symptoms. A high-risk diagnosis of breast and thyroid cancer is associated to Cowden syndrome and the patient should have a yearly follow-up.

Cowden syndrome

Cowden syndrome (CS) is a rare inherited condition characterised by multiple hamartomas in a variety of tissues from all three embryonic layers. It is a cancer predisposition syndrome with an increased risk of developing malignancy in many tissues but especially breast, thyroid and endometrium. It is inherited in an autosomal dominant manner with ∼80% of patients having a germ-line mutation of the PTEN tumour suppressor gene. Presenting signs and symptoms are highly non-specific. Nevertheless clinicians should be able to recognise this syndrome so that patients may be screened for cancerous growths and afforded the opportunity to have genetic testing to assist them and their family members in making medical management decisions. We present a review of this unusual but important condition with particular emphasis on the diagnostic criteria, clinical features, genetics, management and surveillance.

Genetics of the hamartomatous polyposis syndromes: a molecular review

BACKGROUND AND AIMS

Hamartomatous polyposis syndromes are a heterogeneous group of disorders that are inherited in an autosomal dominant fashion. These syndromes only represent a small number of the inherited gastrointestinal cancer predisposition syndromes. However, many of these syndromes carry a substantial risk for developing colorectal cancer, as well as extra-colonic malignancy.

MATERIALS AND METHODS

We searched for articles on inherited hamartomatous polyposis syndromes, including familial juvenile polyposis syndrome, Peutz-Jeghers syndrome, PTEN hamartoma tumor syndrome, multiple endocrine neoplasia syndrome 2B, hereditary mixed polyposis syndrome, Cronkhite-Canada syndrome, basal cell nevus syndrome, and neurofibromatosis 1, in PubMed, Embase, and Elsevier ScienceDirect. In this review, we briefly discuss the diagnosis and clinical features of these disorders and the molecular alterations responsible for these syndromes.

RESULTS AND CONCLUSION

Given the clinical similarities of these hamartomatous syndromes and the autosomal dominant pattern of inheritance, it is sometimes difficult to differentiate hamartomatous polyps, especially with atypical presentation. The molecular analysis and diagnosis make it possible to identify the subtype of these syndromes. In addition, these tests raise an intriguing possibility that surveillance and early medical intervention will allow for the identification of at-risk patients and the reduction of morbidity and mortality.

A case of Cowden's syndrome presenting with gastric carcinomas and gastrointestinal polyposis

BACKGROUND

A 73-year-old white man was referred to a cancer genetics clinic for evaluation of a approximately 20-year history of mixed upper and lower gastrointestinal polyposis, including hyperplastic, inflammatory and adenomatous polyps, colonic ganglioneuromas, and associated diffuse, esophageal glycogenic acanthosis. Two synchronous gastric carcinomas had been identified before referral and the patient had undergone a total gastrectomy, omentectomy and cholecystectomy. Multiple hyperplastic polyps and small, sessile polyps were also observed in the gastrectomy specimen.

INVESTIGATIONS

History and physical examination, upper and lower gastrointestinal endoscopy and biopsy, genetic testing, molecular pathology investigations (immunohistochemistry), thyroid ultrasonography, fine-needle aspiration of a thyroid nodule.

DIAGNOSIS

Cowden's syndrome.

MANAGEMENT

Genetic counseling, thyroidectomy, vitamin B(12) supplementation, continued endoscopic surveillance and genetic testing of at-risk family members.

Hamartomatous polyposis syndromes

Hamartomatous polyposis syndromes are a diverse group of inherited conditions grouped together because they exhibit hamartomatous rather than epithelial polyp histology. Each syndrome exhibits characteristic polyp histology, gastrointestinal polyp distribution, gastrointestinal cancer risks, extra-intestinal benign findings and often extra-intestinal cancer risks. Identifying individuals at risk for these syndromes and accurately defining the precise diagnosis are necessary for planning surveillance and management in order to prevent the benign and malignant complications. Characteristic syndrome features including gastrointestinal findings, pathology, genetics, and management options for the three most common hamartomatous polyposis syndromes, Peutz-Jeghers syndrome, PTEN hamartoma tumour syndrome, and juvenile polyposis will be presented in this review.

Cowden syndrome: a critical review of the clinical literature

Cowden syndrome (CS) is a multi-system disease involving hamartomatous overgrowth of tissues of all three embryonic origins and increased risks for thyroid, breast and possibly other cancers. Benign breast, thyroid, uterine and skin lesions are also common. Approximately 80% of patients with CS have an identifiable germline mutation in the PTEN gene. The majority of the existing data on the frequencies of component clinical features have been obtained from compilations of case reports in the literature, many of which predate the establishment in 1996 of consensus diagnostic criteria. Many of these reports also suffer from ascertainment bias which emphasized the dermatologic features of the disease. This paper presents an overview of Cowden syndrome focusing on a critical evaluation of the major literature on the component cancers, benign features, and molecular findings in CS, noting the limitations of the published data.

Cowden syndrome: a critical review of the clinical literature

Cowden syndrome (CS) is a multi-system disease involving hamartomatous overgrowth of tissues of all three embryonic origins and increased risks for thyroid, breast and possibly other cancers. Benign breast, thyroid, uterine and skin lesions are also common. Approximately 80% of patients with CS have an identifiable germline mutation in the PTEN gene. The majority of the existing data on the frequencies of component clinical features have been obtained from compilations of case reports in the literature, many of which predate the establishment in 1996 of consensus diagnostic criteria. Many of these reports also suffer from ascertainment bias which emphasized the dermatologic features of the disease. This paper presents an overview of Cowden syndrome focusing on a critical evaluation of the major literature on the component cancers, benign features, and molecular findings in CS, noting the limitations of the published data.

PTEN: a new guardian of the genome

The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) tumor suppressor is a phosphatase that antagonizes the phosphoinositol-3-kinase/AKT signaling pathway and suppresses cell survival as well as cell proliferation. PTEN is the second most frequently mutated gene in human cancer after p53. Germline mutations of PTEN have been found in cancer susceptibility syndromes, such as Cowden syndrome, in which over 80% of patients have mutations of PTEN. Homozygous deletion of Pten causes embryonic lethality, suggesting that PTEN is essential for embryonic development. Mice heterozygous for Pten develop spontaneous tumors in a variety of organs comparable with the spectrum of its mutations in human cancer. The mechanisms of PTEN functions in tumor suppression are currently under intense investigation. Recent studies demonstrate that PTEN plays an essential role in the maintenance of chromosomal stability and that loss of PTEN leads to massive alterations of chromosomes. The tumor suppressor p53 is known as a guardian of the genome that mediates the cellular response to environmental stress, leading to cell cycle arrest or cell death. Through completely different mechanisms, PTEN also protects the genome from instability. Thus, we propose that PTEN is a new guardian of the genome. In this review, we will discuss new discoveries on the role of PTEN in tumor suppression and explore mechanisms by which PTEN maintains genomic stability.

Gastrointestinal polyposis with esophageal polyposis is useful for early diagnosis of Cowden’s disease

Cowden’s disease, one of the several hamartoma syndromes, is characterized by hyperplastic lesions and hamartomas distributed in the whole body. About thirty percent of patients with Cowden’s disease have been reported to be complicated by malignant tumors. Based on the criteria of the International Cowden Consortium, this disease is mainly diagnosed as trichilemmoma of the face and oral mucosal papillomatosis. However, Cowden’s disease patients themselves often do not recognize trichilemmoma of the face and oral mucosal papillomatosis. We report a case of Cowden's disease in a 33-year-old female patient who was diagnosed based on the characteristic findings at gastrointestinal endoscopy. Clinically, the patient was aware of having bloody stools. Multiple polyps found endoscopically in the esophagus, stomach, ileum, colon and rectum showed histopathologically hamartomatous changes and epithelial hyperplasia. Physical examination revealed oral papillomatosis and facial trichilemmomas. A germline mutation in exon 8 of the phosphatase and tensin homolog deleted on chromosome ten (PTEN) gene was found in this case. It was a point mutation of C to T at codon 1003 (CGA→TGA, arginine→stop codon). The characteristic findings on gastrointestinal endoscopy led us to a diagnosis of Cowden’s disease. It has been reported that gastrointestinal polyposis with esophageal polyposis is found in about 85.7% of Japanese patients with Cowden’s disease. The characteristic findings on gastrointestinal endoscopy can be a useful diagnostic clue to Cowden's disease.

PTEN hamartoma tumor syndromes

The PTEN hamartoma tumor syndromes (PHTS) are a collection of rare clinical syndromes characterized by germline mutations of the tumor suppressor PTEN. These syndromes are driven by cellular overgrowth, leading to benign hamartomas in virtually any organ. Cowden syndrome (CS), the prototypic PHTS syndrome, is associated with increased susceptibility to breast, thyroid, and endometrial cancer. PTEN is located on chromosome 10q22-23 and negatively regulates the prosurvival PI3K/Akt/mTOR pathway through its lipid phosphatase activity. Loss of PTEN activates this pathway and leads to increased cellular growth, migration, proliferation, and survival. Clinical management of patients with PHTS, particularly those with CS, should include early and frequent screening, surveillance, and preventive care for associated malignancies. Concomitant with improved understanding of the biology of PTEN and the PI3K/Akt/mTOR pathway, inhibitors of this pathway are being developed as anticancer agents. These medications could have applications for patients with PHTS, for whom no medical options currently exist.

Hamartomatous polyposis syndromes

The hamartomatous polyposis syndromes are a heterogeneous group of disorders that share an autosomal-dominant pattern of inheritance and are characterized by hamartomatous polyps of the gastrointestinal tract. These syndromes include juvenile polyposis syndrome, Peutz-Jeghers syndrome and the PTEN hamartoma tumor syndrome. The frequency and location of the polyps vary considerably among syndromes, as does the affected patient's predisposition to the development of gastrointestinal and other malignancies. Although the syndromes are uncommon, it is important for the clinician to recognize these disorders because they are associated with considerable morbidity and mortality, not only from malignancy but also from nonmalignant manifestations such as bleeding, intussusception, and bowel obstruction. Each hamartomatous polyposis syndrome has its own distinctive organ-specific manifestations and each requires a different surveillance strategy, which makes accurate diagnosis crucial for appropriate patient management. The availability of clinical genetic testing for these disorders means that appropriate recognition allows for timely referral for cancer genetic counseling, and often allows for predicative testing in at-risk family members. Promisingly, an understanding of the molecular pathogenesis of these disorders offers insights into the mechanisms underlying the development of sporadic malignancy, and enables rational selection of targeted therapies that warrant further investigation.

Sporadic colonic hamartomas in adults: a retrospective study

BACKGROUND

Colonic hamartomas are uncommon in adults. The aims of this study were to determine (1) the prevalence of colonic hamartomas in an adult population undergoing colonoscopy and (2) the clinical, endoscopic, and histologic features of colonic hamartomas in adult patients.

METHODS

A pathology database identified 19 adult patients of 12,707 patients with colonic hamartomas in the 11-year study period from January 1992 to October 2002. An endoscopic computer database provided information about the number of colonoscopies performed and the presence or the absence of colonic polyp(s) in study patients. Charts of patients with colonic hamartomas were reviewed, and clinical and demographic data were collated.

RESULTS

Nineteen patients were found to have colonic hamartomas. The mean age of these patients was 55 years, with an age distribution ranging from 25 to 81 years. The prevalence of colonic hamartomas in this study population was 0.15%. The prevalence of hamartomas in patients with colon polyps at index colonoscopy was 0.073%. Colonic hamartomas were more common in men than in women. The indication for colonoscopy for the majority (68%) of patients was hematochezia or the presence of occult blood in the stool. Three fourths of the polyps were greater than 1 cm in diameter, and 89% were pedunculated. Two thirds of the hamartomatous polyps were localized to the rectosigmoid region. Endoscopic characteristics of hamartomas were indistinguishable from adenomas.

CONCLUSIONS

Colonic hamartomas in adults are rare. They tend to be single, pedunculated, and localized predominantly in the rectosigmoid region. Endoscopic resection of colonic hamartomas was successful in all patients.

Genetic testing for inherited colon cancer

The genes associated with each of the inherited syndromes of colon cancer have now been identified, and genetic testing is available for diagnosis. These syndromes include familial adenomatous polyposis, hereditary nonpolyposis colorectal cancer, Peutz-Jeghers syndrome, juvenile polyposis syndrome, and, possibly, Cowden's syndrome. Clinical genetic testing approaches have been developed for each of these syndromes and are now a part of accepted clinical care. Disease-causing mutations can be found in the majority of families affected with one of the inherited syndromes, and, most importantly, once a mutation is found in an index case of the family, relatives can be tested for the presence or absence of that mutation with near 100% accuracy. Cancer screening and management in syndrome families is then based on the results of genetic testing. For the physician to order and properly interpret genetic tests, a basic understanding of the types of mutations that lead to inherited disease and the methods for detecting them is vital. These issues will be presented. Additional clinical issues somewhat unique to genetic testing include genetic counseling and informed consent for genetic testing, both of which will also be reviewed. Often the most difficult aspect of genetic testing is deciding which patients and families should undergo the testing. Furthermore, this issue is quite specific for each of the syndromes. Thus, following presentation of general principles of selection for genetic testing, a detailed approach for identifying persons who should undergo testing for each of the individual syndromes will be given, together with relevant descriptions of the syndromes. Finally, the ongoing work to discover new and possibly more common but less penetrant colon cancer susceptibility genes that cause common familial colon cancer will be presented.

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.

The hamartomatous polyposis syndromes: a clinical and molecular review

Inherited forms of gastrointestinal cancer have been a major focus of study and advancement over the past decade. Familial adenomatous polyposis and hereditary nonpolyposis colon cancer are the two most common heritable colon cancer syndromes. Inherited polyposis syndromes are characterized by the dominant type of polyp (whether adenomatous or hamartomatous) present and by the polyp's location within the gastrointestinal tract. The hamartomatous polyposis syndromes are characterized by an overgrowth of cells native to the area in which they normally occur. They represent a small but appreciable number of the gastrointestinal inherited cancer predisposition syndromes; it is now known that many of these syndromes carry a substantial risk for developing colon cancer as well as other gastrointestinal and pancreatic cancers. Patients afflicted with these syndromes are also at significant risk for extraintestinal malignancies. Seven inherited hamartomatous polyposis syndromes have been described: familial juvenile polyposis syndrome, Cowden's syndrome, Bannayan-Ruvalcaba-Riley syndrome, Peutz-Jeghers syndrome, basal cell nevus syndrome, neurofibromatosis 1, and multiple endocrine neoplasia syndrome 2B. Hereditary mixed polyposis syndrome is a variant of juvenile polyposis characterized by both hamartomatous and adenomatous polyps. The hamartomatous syndromes occur at approximately 1/10th the frequency of the adenomatous syndromes and account for <1% of colorectal cancer in Northern America. While the diagnosis of these inherited syndromes is primarily clinical, genetic testing is now available for all six syndromes. However, there are a significant number of spontaneous mutations seen in each of the syndromes. The management of these patients necessitates a coordinated multidisciplinary approach. The purpose of this review is to characterize the clinical and pathological features of these syndromes and to review the targets of cancer surveillance. The molecular alterations responsible for the inherited hamartomatous polyposis syndromes will also be discussed.