Pediatric Challenges With Cowden Syndrome and Graves' Disease: A Case Report

Cowden syndrome is a rare genetic anomaly mostly attributed to mutations in the Phosphatase and Tensin (PTEN) Homolog gene. This illness manifests with a diverse array of symptoms that impact several physiological systems and an increased susceptibility to various forms of malignancy. The patient typically exhibits mucocutaneous lesions and a heightened vulnerability to the formation of neoplasms, specifically thyroid carcinomas. The inclusion of thyroid disorders, such as Graves' disease, introduces complications to the management procedure, necessitating a complete approach that includes many healthcare practitioners to guarantee optimal care. Despite some advancements in the field, there remains a dearth of evidence-based recommendations for pediatric patients, encompassing individuals with Cowden syndrome and other thyroid disorders. The current investigation focuses on a 13-year-old female patient who presents with comorbid Cowden syndrome and Graves' disease. We emphasize the challenges associated with the diagnosis and treatment of these illnesses. A collaborative and multidisciplinary team approach was used to administer therapeutic approaches, such as total thyroidectomy, emphasizing the essential requirement for interdisciplinary cooperation among healthcare providers. Continual research endeavors play a pivotal role in elucidating the optimal management protocols and augmenting outcomes for this particular cohort of individuals.

Gorlin Syndrome and Cowden Syndrome

Gorlin syndrome and Cowden syndrome are hereditary diseases that are characterized by multiple malignancies, cutaneous symptoms, and various other abnormalities. Both disorders are caused by a mutation of the gene that regulates cell proliferation and growth, resulting in tumorigenesis. Representative mutations are mutation in the patched 1 gene (PTCH1) in Gorlin syndrome and mutation in the phosphatase and tensin homolog deleted from chromosome 10 (PTEN) gene in Cowden syndrome. Making a diagnosis of these diseases in the early years of life is important because detection of malignancies at an early stage is linked to improved prognosis. Both Gorlin syndrome and Cowden syndrome have cutaneous findings in the early phase in childhood, and the role of dermatologists is therefore important. These diseases are generally diagnosed by clinical criteria, but some patients who do not meet the criteria need genetic examinations including a genetic diagnostic panel and next-generation sequencing. The most important treatment and management are detection and resection of malignancies in the early stage, and targeted therapies have recently been used for treatment of tumors and other symptoms in these diseases. Although evidence of the effectiveness of targeted therapies has been limited, they are promising therapeutic options and further clinical trials are needed in the future.

Anesthetic Management for a Patient with Rosai-Dorfman Disease, Cowden Syndrome, and Lhermitte-Duclos Disease: An Extremely Rare Disease Combination

Rosai-Dorfman disease (RDD) is a rare condition that causes massive lymphadenopathy, most commonly in the cervical area. Cowden syndrome (CS) causes hamartomas in the skin and mucosa and predisposes individuals to various malignancies. Lhermitte-Duclos disease (LDD), or dysplastic cerebellar gangliocytoma, is often associated with CS. A 41-year-old female with all three conditions presented with abnormal uterine bleeding and endometrial intraepithelial neoplasia (EIN). Precautions should be considered when evaluating patients with RDD and CS preoperatively and during airway management owing to the potential for multisystem involvement, anatomical distortion, and difficult airways. The likelihood of having all three conditions is extremely rare.

Lhermitte-Duclos Disease: A Case Series

Lhermitte-Duclos disease (LDD), or dysplastic cerebellar gangliocytoma, is a rare benign tumor characterized by unilateral hemispheric cerebellar expansion. It is linked to mutations in the phosphatase and tensin homolog (PTEN) gene, which inhibit the phosphatidylinositol-3'-kinase pathway, leading to increased cell division and defective neuronal migration. This study aims to compare the clinical, radiological, histopathological, surgical resolution, and follow-up characteristics of reported cases of this rare condition. An in-depth search of LDD patients' clinical records at our institute between 2003 and 2023 was conducted, in addition to a systematic literature review on PubMed. Three patients with a diagnosis of LDD were found. Cerebellar abnormalities, varying headaches, and visual impairment were all present clinically. On T2 in the posterior fossa, all three MRI scans displayed the typical hyperintense parallel streak appearance. The histopathological report showed that large ganglion cells had replaced the granular layer, Purkinje cells had degenerated, the molecular layer had become hyper-myelinated, and synaptophysin and chromogranin were positive. Partial tumor resection and avoiding intracranial hypertension were the main goals of treatment. Genetic follow-up was conducted for all three patients. Neurosurgeons must be aware of LDD to provide close genetic monitoring despite the benign nature of the tumor because of its link to Cowden syndrome and elevated risk of cancer in other organs.

Cowden Syndrome With Gall Bladder Polyps and Incidental Gall Bladder Carcinoma

Cowden syndrome is an uncommon autosomal dominant disorder characterized by multiple hamartomas in various tissues. It is associated with germline mutation in the phosphatase and tensin homolog (PTEN) gene. It has an increased risk of malignancies of various organs (commonly breast, thyroid, and endometrium) and benign overgrowth of tissues like skin, colon, and thyroid. Here, we present a case of Cowden syndrome in a middle-aged female who presented with acute cholecystitis with gall bladder polyps along with intestinal polyps. She underwent total proctocolectomy with ileal pouch-anal anastomosis (IPAA) with diversion ileostomy and cholecystectomy, which was further proceeded to completion of radical cholecystectomy based on the final histopathology report as incidental gall bladder carcinoma. To the best of our knowledge, this association is seen for the first time in the literature. In Cowden syndrome, patients should be counseled for regular follow-up and instructed to be aware of the signs and symptoms of different types of cancers with higher incidence.

Squamous Papilloma on the Hard Palate: A Rare Clinical Entity

Squamous papilloma is a benign, exophytic, soft tissue tumour caused by the rapid proliferation of stratified squamous epithelium. It typically manifests in the oral cavity as a painless, soft, non-tender, pedunculated growth that resembles a cauliflower. This case report of squamous papilloma on the hard palate sheds light on the etiopathogenesis, types, clinical features, differential diagnosis, and management modalities.

Clinical and genetic diagnosis of Cowden syndrome: A case report of a rare PTEN germline variant and diverse clinical presentation

INTRODUCTION

Cowden syndrome is a rare autosomal dominant disease characterized by the development of hamartomas and increased risks of other tumors, including breast, thyroid, and uterine cancers. Most patients with Cowden syndrome show mutations of the phosphatase and tensin homolog (PTEN) gene on chromosome 10; however, some patients with mutations do not show clinical symptoms, while patients with clinical symptoms may not have detectable PTEN mutations.

CASE PRESENTATION

A 39-year-old woman with macrocephaly had previously been diagnosed with Cowden syndrome at another hospital, when she presented with the onset of breast cancer. A wide variety of complications were detected, including cerebellar tumors treated by resection, hydrocephalus, and multiple polyps in the stomach and large intestine. She was further diagnosed with adult-onset Lhermitte-Duclos disease as a complication of Cowden syndrome. She subsequently developed a dural arteriovenous fistula treated by transvenous embolization. After transfer to our hospital, she developed adenomatous goiter treated by resection, recurrent breast cancer treated with hormonal therapy, and multifocal oral mucosal papillomatosis. Her older sister had previously been diagnosed with Cowden syndrome and her father was undiagnosed but had macrocephaly, hydrocephalus, and multifocal oral mucosal papillomatosis, suggestive of Cowden syndrome. After consultation with a genetic specialist, analysis of the PTEN gene showed a rare but likely pathogenic germline c.801 + 2T>A variant located at the splice donor site of intron 7. The patient's clinical diagnosis of Cowden syndrome was accordingly confirmed by the genetic findings. Appropriate surveillance procedures were put in place to detect any further tumors.

CONCLUSIONS

The clinical symptoms of Cowden syndrome do not always correlate with the genetic results. However, recent improvements in genetic testing suggest the importance of diagnosing this disease using both clinical and genetic approaches, in collaboration with genetic experts, to ensure an accurate diagnosis and appropriate surveillance for malignant tumors.

Cowden Syndrome Case Report: Use of an Ultrasonic Surgical Aspirator for Cosmetic Removal of Lip Hamartomas

Cowden syndrome (CS) is an autosomal dominant condition that is relatively rare. CS patients can have tumors derived from all three germlines. They can present with mucocutaneous hamartomas or other benign tumors, and have an increased risk of malignancies of the thyroid, breast, kidney, GI tract, and skin. In our clinic, a 40-year-old CS patient presented for thyroidectomy after fine needle aspiration was suspicious for papillary thyroid carcinoma (PTC). Another major concern was the cosmetic appearance of her lips, which were diffusely covered with small hamartomas. We were able to remove these in a novel manner using a cavitron ultrasonic surgical aspirator (CUSA; Integra Lifesciences, Princeton, NJ, USA). Using the CUSA tangential to the lip surface allowed for removal of the hamartomas in a way that created a smooth and cosmetically appealing outcome for the patient. The use of an ultrasonic surgical aspirator is a novel way to cosmetically treat hamartomas of the lip for CS patients.

Diffuse Gastrointestinal Polyposis in Bannayan-Riley-Ruvalcaba Syndrome: A Rare Phenotype Among Phosphatase and Tensin Homolog Hamartoma Tumor Syndromes

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a rare genetic disorder caused by germline mutations in the phosphatase and tensin homolog (PTEN) gene. Clinical manifestations arise early during childhood and include multiple lipomas, hamartomatous intestinal polyps, macrocephaly, developmental delay, and autism spectrum disorder among others. The case describes a 24-year-old female with a recent diagnosis of BRRS who presented for evaluation of burning epigastric pain for the previous six months. The esophagogastroduodenoscopy (EGD) and colonoscopy revealed an erosive gastric mucosa as well as numerous polyps throughout the gastrointestinal tract. Histopathologic examination confirmed gastric Helicobacter pylori infection and different histologic types of polyps.

Multiple Meningiomata in Cowden Syndrome

Cowden syndrome (CS) is a rare, congenital disease with associated cancers, but in a neurosurgical context is typically considered part of Lhermitte-Duclos. This misrepresentation is the likely cause of under-diagnosis. Furthermore, the presence of meningiomata has been described in CS patients but its absence as part of the condition's major criteria suggest the correlation requires greater documentation. A 41-year-old woman with multiple cancers and a familial circumambience of CS was reviewed in clinic where multiple meningiomata were incidentally identified on MRI. Despite a lack of neurological impairment, and the general reluctance in treating the meningiomas of congenital disease with radiotherapy (RT), the patient underwent stereotactic radio-surgery (SRS) and at one-year post-procedure has reported no side effects or toxicity.

A Male Patient With Breast Hamartoma: An Uncommon Finding

Mammary hamartoma is a rare type of breast tumor that is composed of the same elements as normal mammary tissue. This condition is very rare in men. In current literature, there are fewer than five case reports on male breast hamartoma. This benign pathology is under-reported because of several reasons. Since breast tumors are still considered an exclusively female diagnosis and statistically proven to be gynecomastia when arising in men, they are often overlooked. In addition to the uncommon clinical presentation in men, insufficiency of definitive pathologic and radiologic characteristics can make an accurate diagnosis a challenging task. Mammary hamartoma is a benign condition with an excellent prognosis. The following case describes a rare instance of an enlarging mammary hamartoma in a male patient, highlighting the imaging features, pathohistological findings, and clinical management.

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.

PTEN interacts with RNA polymerase II to dephosphorylate polymerase II C-terminal domain

Gene transcription is a highly complex and strictly regulated process. RNA polymerase II (Pol II) C-terminal domain (CTD) undergoes massive cycles of phosphorylation and dephosphorylation during the process of gene transcription. These post-translational modifications of CTD provide an interactive platform for various factors required for transcription initiation, elongation, termination, and co-transcriptional RNA processing. Pol II CTD kinases and phosphatases are key regulators and any deviation may cause genome-wide transcriptional dysregulation leading to various pathological conditions including cancer. PTEN, a well known tumor suppressor, is one of the most commonly somatically altered in diverse malignancies. When mutated in the germline, PTEN causes cancer predisposition. Numerous studies have demonstrated that PTEN regulates the expression of hundreds of genes, however, no mechanism is known so far. PTEN is a dual specificity phosphatase, using both lipid and protein as substrates. In the present study, we demonstrate that PTEN interacts with the RNA Pol II and that PTEN expression is inversely correlated with global phosphorylation of Pol II CTD. Furthermore, PTEN dephosphorylates Pol II CTD in vitro with a significant specificity for Ser5p. Interestingly, ChIP-seq data analysis revealed that PTEN globally binds to promoter proximal regions, and PTEN loss increases genome-wide Pol II Ser5p occupancy, suggest that PTEN is a Pol II CTD phosphatase. Our observations demonstrate an unexplored function of PTEN with the potential of global transcriptional regulation, adding a new dimension to somatic carcinogenesis and germline cancer predisposition.

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.

Where Birt-Hogg-Dubé meets Cowden syndrome: mirrored genetic defects in two cases of syndromic oncocytic tumours

Birt-Hogg-Dubè (BHD) is an autosomal dominant syndrome characterised by skin fibrofolliculomas, lung cysts, spontaneous pneumothorax and renal cancer. The association of benign cutaneous lesions and increased cancer risk is also a feature of Cowden Syndrome (CS), an autosomal dominant disease caused by PTEN mutations. BHD and CS patients may develop oncocytomas, rare neoplasias that are phenotypically characterised by a prominent mitochondrial hyperplasia. We here describe the genetic analysis of a parotid and a thyroid oncocytoma, developed by a BHD and a CS patient, respectively. The BHD lesion was shown to maintain the wild-type allele of FLCN, while losing one PTEN allele. On the other hand, a double heterozygosity for the same two genes was found to be the only detectable tumorigenic hit in the CS oncocytoma. Both conditions occurred in a context of high chromosomal stability, as highlighted by comparative genomic hybridisation analysis. We conclude that, similarly to PTEN, FLCN may not always follow the classical Two Hits model of tumorigenesis and may hence belong to a class of non-canonical tumour suppressor genes. We hence introduce a role of PTEN/FLCN double heterozygosity in syndromic oncocytic tumorigenesis, suggesting this to be an alternative determinant to pathogenic mitochondrial DNA mutations, which are instead the genetic hallmark of sporadic oncocytic tumours.

Prevalence of germline PTEN, BMPR1A, SMAD4, STK11, and ENG mutations in patients with moderate-load colorectal polyps

BACKGROUND & AIMS

Gastrointestinal polyposis is a common clinical problem, yet there is no consensus on how to best manage patients with moderate-load polyposis. Identifying genetic features of this disorder could improve management and especially surveillance of these patients. We sought to determine the prevalence of hamartomatous polyposis-associated mutations in the susceptibility genes PTEN, BMPR1A, SMAD4, ENG, and STK11 in individuals with ≥5 gastrointestinal polyps, including at least 1 hamartomatous or hyperplastic/serrated polyp.

METHODS

We performed a prospective, referral-based study of 603 patients (median age: 51 years; range, 2-89 years) enrolled from June 2006 through January 2012. Genomic DNA was extracted from peripheral lymphocytes and analyzed for specific mutations and large rearrangements in PTEN, BMPR1A, SMAD4, and STK11, as well as mutations in ENG. Recursive partitioning analysis was used to determine cutoffs for continuous variables. The prevalence of mutations was compared using Fisher's exact test. Logistic regression analyses were used to determine univariate and multivariate risk factors.

RESULTS

Of 603 patients, 119 (20%) had a personal history of colorectal cancer and most (n = 461 [76%]) had <30 polyps. Seventy-seven patients (13%) were found to have polyposis-associated mutations, including 11 in ENG (1.8%), 13 in PTEN (2.2%), 13 in STK11 (2.2%), 20 in BMPR1A (3.3%), and 21 in SMAD4 (3.5%). Univariate clinical predictors for risk of having these mutations included age at presentation younger than 40 years (19% vs 10%; P = .008), a polyp burden of ≥30 (19% vs 11%; P = .014), and male sex (16% vs 10%; P = .03). Patients who had ≥1 ganglioneuroma (29% vs 2%; P < .001) or presented with polyps of ≥3 histologic types (20% vs 2%; P = .003) were more likely to have germline mutations in PTEN.

CONCLUSIONS

Age younger than 40 years, male sex, and specific polyp histologies are significantly associated with risk of germline mutations in hamartomatous-polyposis associated genes. These associations could guide clinical decision making and further investigations.

Diffuse intestinal ganglioneuromatosis in a child

A 7 year old male with a history of congenital neutropenia and growth hormone deficiency presented with abdominal pain, fevers, and diarrhea. Imaging and endoscopy revealed significant inflammation of the ascending colon with stenosis at the level of the hepatic flexure. A right hemicolectomy was performed, and pathologic findings were consistent with diffuse intestinal ganglioneuromatosis. Due to recurrent mass effect at the intestinal anastomotic site detected radiologically, a second intestinal resection was performed 7 months later. Genetic testing was negative for mutations in the RET protooncogene, NF1 and PTEN tumor suppressor genes. We report a case of diffuse intestinal ganglioneuromatosis in a child with congenital neutropenia.

Elevated plasma succinate in PTEN, SDHB, and SDHD mutation-positive individuals

PURPOSE

Cowden syndrome results from germline mutations in the gene for phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and from variants in succinate dehydrogenase B and D subunits. We hypothesized that succinate accumulation may be common among individuals with SDH variants/mutations and those with PTEN mutations.

METHODS

Urine and blood were collected from individuals meeting full or partial Cowden syndrome diagnostic criteria or those with paraganglioma (PGL) or a known susceptibility paraganglioma-associated gene mutation, and succinate was measured. PTEN, SDHB, SDHC, and SDHD genes were sequenced from genomic DNA.

RESULTS

Elevated plasma succinate was observed in 13/21 (62%) individuals with germline PTEN, SDHB, or SDHD mutations as compared with 5/32 (16%) controls (P < 0.001), in 10/15 (67%) individuals with pathogenic PTEN mutations but in <20% of mutation-negative individuals meeting identical criteria, and in individuals with mutations in SDHB (1/1, 100%) and SDHD (2/5, 40%).

CONCLUSION

Our data suggest that mutations in PTEN, SDHB, and SDHD reduce catalytic activity of succinate dehydrogenase, resulting in succinate accumulation, and identify a common biochemical alteration in these two patient populations (PTEN and SDHx mutation positive individuals). Plasma organic acid analysis may provide an effective and inexpensive screening method to determine when more expensive gene sequencing of PTEN and SDH genes is warranted.

Testicular pain as a presentation of Cowden syndrome

This case report outlines a rare case in Cowden syndrome and PTEN (phosphatase and tensin homolog) gene mutation and how it may initially present to the urologist. Also known as multiple hamartoma syndrome, Cowden syndrome is a rare disorder associated with the development of several types of malignancy. A thorough search of the literature reveals limited information regarding its presentation to the urologist. We report the case of a 47-year-old gentleman with a two-week history of worsening pain and swelling in his left testicle. Testicular ultrasound revealed multiple hyperechoic areas bilaterally suggestive of multiple lipomas. He was also found to have macrocephaly, freckling of his glans and foreskin and an enlarged nodular goitre and the geneticist diagnosed Cowden syndrome. The disease is discussed and guidance is given on its management and follow up.

Germline epigenetic regulation of KILLIN in Cowden and Cowden-like syndrome

CONTEXT

Germline loss-of-function phosphatase and tensin homolog gene (PTEN) mutations cause 80% of Cowden syndrome, a rare autosomal-dominant disorder (1 in 200,000 live births), characterized by high risks of breast, thyroid, and other cancers. A large heterogeneous group of individuals with Cowden-like syndrome, who have various combinations of Cowden syndrome features but who do not meet Cowden syndrome diagnostic criteria, have PTEN mutations less than 10% of the time, making molecular diagnosis, prediction, genetic counseling, and risk management challenging. Other mechanisms of loss of function such as hypermethylation, which should result in underexpression of PTEN or of KILLIN, a novel tumor suppressor transcribed in the opposite direction, may account for the remainder of Cowden syndrome and Cowden-like syndrome.

OBJECTIVE

To determine whether germline methylation is found in Cowden syndrome or Cowden-like syndrome in individuals lacking germline PTEN mutations.

DESIGN, SETTING, AND PARTICIPANTS

Nucleic acids from prospective nested series of 123 patients with Cowden syndrome or Cowden-like syndrome and 50 unaffected individuals without PTEN variants were analyzed for germline methylation and expression of PTEN and KILLIN at the Cleveland Clinic, August 2008-June 2010. Prevalence of component cancers between groups was compared using the Fisher exact test.

MAIN OUTCOME MEASURES

Frequency of germline methylation in PTEN mutation-negative Cowden syndrome and Cowden syndrome-like individuals. Prevalence of component cancers in methylation-positive and PTEN mutation-positive individuals.

RESULTS

Of 123 patients with Cowden syndrome or Cowden-like syndrome, 45 (37%; 95% confidence interval [CI], 29%-45%) showed hypermethylation upstream of PTEN but no transcriptional repression. The germline methylation was found to transcriptionally down-regulate KILLIN by 250-fold (95% CI, 45-14 286; P = .007) and exclusively disrupted TP53 activation of KILLIN by 30% (95% CI, 7%-45%; P = .008). Demethylation treatment increased only KILLIN expression 4.88-fold (95% CI, 1.4-18.1; P = .05). Individuals with KILLIN -promoter methylation had a 3-fold increased prevalence of breast cancer (35/42 vs 24/64; P < .0001) and a greater than 2-fold increase of kidney cancer (4/45 vs 6/155; P = .004) over individuals with germline PTEN mutations.

CONCLUSIONS

Germline KILLIN methylation is common among patients with Cowden syndrome or Cowden-like syndrome and is associated with increased risks of breast and renal cancer over PTEN mutation-positive individuals. These observations need to be replicated.

Frequent gastrointestinal polyps and colorectal adenocarcinomas in a prospective series of PTEN mutation carriers

BACKGROUND & AIMS

Germline phosphatase and tensin homolog (PTEN) mutations cause Cowden syndrome (CS), associated with breast and thyroid cancers. Case reports found 35%-85% of CS patients had gastrointestinal (GI) hamartomas. The association of benign and malignant GI neoplasias with CS remains debatable. Our goal is to describe the GI phenotype in a prospective series of PTEN mutation carriers.

METHODS

Patients who met relaxed International Cowden Consortium criteria (N = 2548) or with 5 or more GI polyps, 1 or more of which was hyperplastic or hamartomatous (N = 397), were prospectively recruited. Germline PTEN mutation/deletion analysis was performed. Of the 2945 patients, 127 (123 of 2548 and 4 of 397, respectively) patients having clear pathogenic PTEN mutations were eligible for this study. Esophagogastroduodenoscopy, colonoscopy, and pathology reports were reviewed. The Fisher 2-tailed exact test, unpaired t tests, and age- and sex-adjusted standardized incidence ratio were calculated.

RESULTS

Of 127 PTEN mutation carriers, 69 underwent 1 or more endoscopies with 64 (93%) having polyps. Of the 64, half had hyperplastic polyps. There were one to innumerable polyps in the colorectum, ileum, duodenum, stomach, and/or esophagus, with 24 subjects having both upper and lower GI polyps. Nine (13%) subjects had colorectal cancer, all younger than the age of 50. The adjusted standardized incidence ratio was 224.1 (95% confidence interval, 109.3-411.3; P < .0001).

CONCLUSIONS

PTEN-associated CS should be considered a mixed polyp syndrome, with hyperplastic polyps most prevalent, with a risk of early onset colorectal cancer. Routine colonoscopy should be considered in PTEN-associated CS, especially in the context of hyperplastic and/or adenomatous polyps.

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.

Dysregulation of the phosphatidylinositol 3-kinase pathway in thyroid neoplasia

The phosphatidylinositol 3-kinase (PI3K) signaling pathway is an important regulator of many cellular events, including apoptosis, proliferation, and motility. Enhanced activation of this pathway can occur through several mechanisms, such as inactivation of its negative regulator, phosphatase and tensin homolog deleted on chromosome ten (PTEN), and activating mutations and gene amplification of the gene encoding the catalytic subunit of PI3K (PIK3CA). These genetic abnormalities have been particularly associated with follicular thyroid neoplasia and anaplastic thyroid cancer, suggesting an important role for PI3K signaling in these disorders. In this article, the role of PI3K pathway activation in thyroid cancer is discussed, with a focus on recent advances.

Cowden syndrome and Bannayan Riley Ruvalcaba syndrome represent one condition with variable expression and age-related penetrance: results of a clinical study of PTEN mutation carriers

BACKGROUND

The most commonly reported phenotypes described in patients with PTEN mutations are Bannayan-Riley-Ruvalcaba syndrome (BRRS), with childhood onset, macrocephaly, lipomas and developmental delay, and Cowden Syndrome (CS), an adult-onset condition recognised by mucocutaneous signs, with a risk of cancers, in particular those of the thyroid and breast. It has been suggested that BRRS and CS are the same condition, but the literature continues to separate them and seek a genotype-phenotype correlation.

OBJECTIVE

To study the clinical features of patients with known PTEN mutations and observe any genotype-phenotype correlation.

METHODS

In total, 42 people (25 probands and 17 non-probands) from 26 families of all ages with PTEN mutations were recruited through the UK clinical genetics services. A full clinical history and examination were undertaken.

RESULTS

We were unable to demonstrate a genotype-phenotype correlation. Furthermore, our findings in a 31-year-old woman with CS and an exon 1 deletion refutes previous reports that whole exon deletions are only found in patients with a BRRS phenotype.

CONCLUSION

Careful phenotyping gives further support for the suggestion that BRRS and CS are actually one condition, presenting variably at different ages, as in other tumour-suppressor disorders such as neurofibromatosis type 1. This has important counselling implications, such as advice about cancer surveillance, for children diagnosed with BRRS.

Mutation screening of the PTEN gene in patients with autism spectrum disorders and macrocephaly

Mutations in the PTEN gene are associated with a broad spectrum of disorders, including Cowden syndrome (CS), Bannayan-Riley-Ruvalcaba syndrome, Proteus syndrome, and Lhermitte-Duclos disease. In addition, PTEN mutations have been described in a few patients with autism spectrum disorders (ASDs) and macrocephaly. In this study, we screened the PTEN gene for mutations and deletions in 88 patients with ASDs and macrocephaly (defined as >or=2 SD above the mean). Mutation analysis was performed by direct sequencing of all exons and flanking regions, as well as the promoter region. Dosage analysis of PTEN was carried out using multiplex ligation-dependent probe amplification (MLPA). No partial or whole gene deletions were observed. We identified a de novo missense mutation (D326N) in a highly conserved amino acid in a 5-year-old boy with autism, mental retardation, language delay, extreme macrocephaly (+9.6 SD) and polydactyly of both feet. Polydactyly has previously been described in two patients with Lhermitte-Duclos disease and CS and is thus likely to be a rare sign of PTEN mutations. Our findings suggest that PTEN mutations are a relatively infrequent cause of ASDs with macrocephaly. Screening of PTEN mutations is warranted in patients with autism and pronounced macrocephaly, even in the absence of other features of PTEN-related tumor syndromes.