PTEN Hamartoma Tumor Syndrome Research Articles

Update on Pediatric Surveillance Recommendations for PTEN Hamartoma Tumor Syndrome, DICER1-Related Tumor Predisposition, and Tuberous Sclerosis Complex.

PTEN hamartoma tumor syndrome (PHTS), DICER1-related tumor predisposition (DICER1) and tuberous sclerosis complex (TSC) are rare conditions which each increase risk for distinct spectra of benign and malignant neoplasms throughout childhood and adulthood. Surveillance considerations for each of these conditions focus on patient and family education, early detection and multidisciplinary care. In this manuscript, we present updated surveillance recommendations and considerations for children and adolescents with PHTS, DICER1 and TSC and provide suggestions for further research in each of these conditions.

Quantifying neurobehavioral profiles across neurodevelopmental genetic syndromes and idiopathic neurodevelopmental disorders.

To examine neurobehavioral findings in three genetic syndromes (PTEN hamartoma tumor syndrome, Malan syndrome [mutations in the NFIX gene], and SYNGAP1-related disorder), a mixed group of other neurodevelopmental genetic syndromes (NDGS), idiopathic neurodevelopmental disorder, and neurotypical control participants. Using a longitudinal case-control design, caregivers reported neurobehavioral information for 498 participants (PTEN hamartoma tumor syndrome n = 112, Malan syndrome n = 24, SYNGAP1-related disorder n = 47, other NDGS n = 72, idiopathic neurodevelopmental disorder n = 54, neurotypical siblings n = 74, and unrelated neurotypical control participants n = 115) at three timepoints (baseline, and 1-month and 4-month follow-ups) using the online-administered Neurobehavioral Evaluation Tool (NET). NET scales had good scale and test-retest reliability. Unique patterns of neurobehavioral findings emerged, with SYNGAP1-related disorder and Malan syndrome showing generally more severe symptom and skill patterns than for other groups of patients. Patterns could be partly accounted for by estimated cognitive level, speech level, and the presence of autism spectrum disorder. However, even when accounting for these factors, group differences remained. Reliable change indices are reported. Genetic syndromes associated with neurodevelopmental disorders present with unique neurobehavioral profiles that can inform selection of outcome measures in future clinical trials. The NET may be a useful screening and monitoring instrument in clinical practice, where frequent in-person clinic attendance is difficult for many patients.

PTEN and novel TEK germline variants associated with the phenotypes of PTEN hamartoma tumor syndrome

PTEN and novel TEK germline variants associated with the phenotypes of PTEN hamartoma tumor syndrome

7925 Cowden Disease Occurring in Association with Common Variable Hypogammaglobulinemia: A Case Report

Abstract Disclosure: M.K. Shakir: None. I.C. Ebrahim: None. D.B. Maxwell: None. N.O. Vietor: None. T.D. Hoang: None. Carriers of a pathogenic germline mutations in the PTEN gene, a tumor suppressor gene, are at increased risk of multiple benign and malignant tumors, including thyroid, breast, endometrial and colon cancer, termed as PTEN Hamartoma Tumor Syndrome (PHTS). Recent studies have shown that PHTS patients may also have an increased risk of immunological dysregulation, such as autoimmunity and immune deficiencies. We are reporting a 47-year-old female with Cowden disease (CD) and common variable hypogammaglobulinemia (CVH). Our patient was diagnosed with CVH at the age of 25 after several episodes of pneumonia as well as poor wound healing. Since then, she is being treated with monthly intravenous immunoglobulin therapy. At the age of 24 years, she had a fainting episode and a diagnosis of gangliocytoma of cerebellum was made and she underwent resection of the tumor. At this time, she was also diagnosed with CD. She has a personal history of multiple other tumors including phyllodes tumor of breast, s/p bilateral mastectomy at the age of 32, status post hysterectomy for endometrial hyperplasia at the age 35. Hurthle cell adenomas of thyroid s/p total thyroidectomy at the age of 38. Her family history was significant for sister and father with CD. Physical examination was remarkable for only acral keratosis without mucocutaneous neuromas, oral papillomas and trichilemmomas. Cowden syndrome is the best-described phenotype of PHTS; it is characterized by mucocutaneous lesions and an elevated risk of breast, thyroid, endometrial, colorectal, and renal cancers as well as various benign manifestations such as macrocephaly and dysplastic gangliocytoma of the cerebellum. Our patient was diagnosed with CD when she presented with gangliocytoma of the cerebellum. Immunodeficiency has been reported previously in patients with CD, and these patients often present with recurrent cellulitis and abscesses, and reduced T cell numbers and in vitro T cell proliferative function. Thus, PHTS patients may also have an increased risk of immunological dysregulation, such as autoimmunity and immune deficiencies. Additionally, a decreased ability of dendritic cells to prime CD8+ T cells may occur, leading to impaired tumor eradication. Immune dysfunction in PHTS patients might be a potentially manageable contributing factor to the increased cancer risk in PHTS. In conclusion, patients presenting with CD should also be screened for disorders of immunological dysregulation. Presentation: 6/2/2024

12345 Staying Ahead of Cowden’s Syndrome in Differentiated Thyroid Cancer

Abstract Disclosure: M.S. Gordon: None. M.B. Gordon: None. Cowden’s syndrome or multiple hamartoma syndrome, is an uncommon autosomal dominant genodermatosis and is a member of the spectrum of disorders involving mutations in the phosphatase and tensin homolog gene (PTEN). It is associated with differentiated thyroid cancer (DTC), ¾ papillary, including follicular variant (FVPTC), 1/4 follicular (FTC), and other malignancies, including breast (most common), colorectal, renal cell, endometrial and skin cancers. We report a case of Cowden’s syndrome in which the patient presented with FVPTC but had no other apparent indication of a genetic abnormality until she was found to have a melanoma and was noted to have macrocephaly. The patient presented at age 26 with a thyroid nodule of 2.7 cm in maximal dimension. FNA was benign. By age 31 the lesion had grown to 3.3 cm and a repeat FNA showed a follicular neoplasm. She underwent left lobectomy and isthmusectomy revealing a 3.0 cm FVPTC with focal Hurthle cell features. There was capsular irregularity, and subsequently she underwent completion thyroidectomy showing a right sided 8mm FVPTC. She then received 30 mCi I 131. There were no apparent pathologic mucocutaneous lesions, intellectual deficits, and no family history of Cowden’s syndrome. At age 39 she was found to have a Stage IA malignant melanoma of the periumbilical skin which was resected. With two malignancies diagnosed at a relatively young age, she was evaluated for genetic syndromes and it was simultaneously noted that she had macrocephaly with head circumference of 66 cm. (>99 percentile). An analysis of 69 genes by Ambry genetics revealed a pathogenic variant in the PTEN gene (c.388 C>T (p.R130*). PTEN R130* results in a premature truncation of the PTEN protein at amino acid 130 of 403 within the phosphatase tensin-type domain resulting in loss of function. Macrocephaly (2% population frequency) is seen in 80% of patients with PTEN mutations. Twenty percent of patients with thyroid carcinoma and macrocephaly have a PTEN mutation and lifetime risk of melanoma in DTC is 25%. BRAF and RAS mutations may cooperate with PTEN loss and explain the increased co-occurrence of malignancies with BRAF and RAS mutations such as melanoma, FTC, and PTC in Cowden’s syndrome. In conclusion, we suggest that head circumference should be measured in all patients with DTC to screen for PTEN abnormalities. Patients with DTC also should have a thorough skin examination. Presentation: 6/2/2024

Quantitative evaluation of DNA damage repair dynamics to elucidate predictors of autism vs. cancer in individuals with germline PTEN variants.

Persons with germline variants in the tumor suppressor gene phosphatase and tensin homolog, PTEN, are molecularly diagnosed with PTEN hamartoma tumor syndrome (PHTS). PHTS confers high risks of specific malignancies, and up to 23% of the patients are diagnosed with autism spectrum disorder (ASD) and/or developmental delay (DD). The accurate prediction of these two seemingly disparate phenotypes (cancer vs. ASD/DD) for PHTS at the individual level remains elusive despite the available statistical prevalence of specific phenotypes of the syndrome at the population level. The pleiotropy of the syndrome may, in part, be due to the alterations of the key multi-functions of PTEN. Maintenance of genome integrity is one of the key biological functions of PTEN, but no integrative studies have been conducted to quantify the DNA damage response (DDR) in individuals with PHTS and to relate to phenotypes and genotypes. In this study, we used 43 PHTS patient-derived lymphoblastoid cell lines (LCLs) to investigate the associations between DDR and PTEN genotypes and/or clinical phenotypes ASD/DD vs. cancer. The dynamics of DDR of γ-irradiated LCLs were analyzed using the exponential decay mathematical model to fit temporal changes in γH2AX levels which report the degree of DNA damage. We found that PTEN nonsense variants are associated with less efficient DNA damage repair ability resulting in higher DNA damage levels at 24 hours after irradiation compared to PTEN missense variants. Regarding PHTS phenotypes, LCLs from PHTS individuals with ASD/DD showed faster DNA damage repairing rate than those from patients without ASD/DD or cancer. We also applied the reaction-diffusion partial differential equation (PDE) mathematical model, a cell growth model with a DNA damage term, to accurately describe the DDR process in the LCLs. For each LCL, we can derive parameters of the PDE. Then we averaged the numerical results by PHTS phenotypes. By performing simple subtraction of two subgroup average results, we found that PHTS-ASD/DD is associated with higher live cell density at lower DNA damage level but lower cell density level at higher DNA damage level compared to LCLs from individuals with PHTS-cancer and PHTS-neither.

Clinical, histological and receptor profiles of invasive breast cancer and ductal carcinoma in situ in females with germline pathogenic variants in PTEN and implications for germline testing

PTEN hamartoma tumour syndrome (PHTS) is an autosomal dominant hereditary cancer syndrome, caused mostly by germline pathogenic variants in PTEN. Female carriers have an up to 80% lifetime risk of breast cancer. Pathologic features of breast cancer in PHTS have seldom been reported.In a collaboration between all histopathology laboratories in our state and our statewide familial cancer service, we tracked the breast biopsies of 12 females with known PTEN pathogenic or likely pathogenic variants (Jan 1990 to Jan 2018). Two further cases were added by a Victorian cancer genetics unit.Breast cancer, inclusive of invasive cancer or ductal carcinoma in situ (DCIS), was diagnosed in 12 of 14 cases (85.7%). One case had a family history of PHTS and six a family history of breast cancer. The mean age at first breast cancer diagnosis was 41.6 years (range 27-63). Six cases developed more than one breast cancer. Five (42%) developed contralateral breast cancer. Ten of the 12 invasive cancers were of no special type, two were reported as lobular carcinomas. None were grade 1. When reported, all cancers were hormone receptor positive and HER2 negative. All were associated with DCIS. The DCIS spanned all grades.The two cases without breast cancer still required surgery for exuberant benign changes, including papillomas, fibroadenomatoid change, florid ductal epithelial hyperplasia, adenosis and stromal fibrosis.We note that the morphology and receptor profiles of breast cancer in individuals with P/LP PTEN variants are not distinctive. Contrary to prevalent beliefs, these cancers do not conform to the contemporary definition of apocrine breast carcinoma. Greater familiarity of healthcare professionals with the overall clinical and pathologic findings in PHTS and the validated Cleveland Clinic PTEN calculator (http://www.lerner.ccf.org/gmi/ccscore) would improve the recognition of female PHTS individuals with breast cancer. Earlier identification of their cancer predisposition syndrome would benefit these patients and their families who are at high risk of a range of cancers.

Pathologists' integration of prior biopsies of women with germline PTEN mutations may expedite the identification of this rare cancer predisposition syndrome

PTEN hamartoma tumour syndrome (PHTS) is a rare cancer predisposition syndrome, caused chiefly by pathogenic and likely pathogenic (P/LP) variants in in the PTEN gene. Carriers have substantially elevated risks of various malignancies and develop benign lesions in multiple organ systems. The rarity of this disease, the decades long unfolding of its clinical features, involvement of multiple sites and the absence of distinguishing features of each lesion hamper the identification of this condition, limiting opportunities for screening of affected individuals and their families. Given laboratory information systems are the repositories of patients' biopsies, we are interested in whether PHTS patients' prior biopsies may serve as clues to the possibility of this syndrome. With ethics committee approval, through a collaboration amongst our state-wide Adult Genetics Unit and all pathology laboratories in our state, we have undertaken a 28-year longitudinal survey (1990–2018) of the biopsy histories of 12 women known to have P/LP PTEN variants. Only one woman had a family history of Cowden syndrome, with the remaining 11 patients' mutations becoming discovered later. The earliest biopsy was at age 19. The most common finding was the development of multiple benign mucocutaneous lesions, with 10 women presenting with these. These included a range of benign vascular lesions: eight patients, various fibromatous lesions of the skin and mucosal sites: six patients, a ganglioneuroma and a juvenile polyp. Ten women developed breast cancer, only four before the age of 40. Seven women developed a second breast cancer, two synchronously and five at intervals of 3–11 years. Other neoplasms included endometrial carcinoma (two patients) and dysplastic cerebellar gangliocytoma (three patients). Integrating the biopsy histories of PTEN P/LP variant carriers over time may assist in raising the possibility of an underlying cancer susceptibility syndrome, so appropriate clinical and genetic counselling and evaluation may be considered.

A systematic review of Bannayan – Riley – Ruvalcaba syndrome

Bannayan–Riley–Ruvalcaba syndrome (BRRS) is a rare overgrowth condition caused by a pathogenic variant in the phosphatase and tensin homolog (PTEN) gene and belongs to a group of disorders called PTEN hamartoma tumor syndrome (PHTS). The diagnosis is often complicated by great phenotypic diversity. Furthermore, to this date treatment options are limited. Here we performed a systematic review using PubMed, Cochrane, and Scopus databases to identify cases of pediatric patients diagnosed with BRRS and summarized information about the clinical presentation, treatment, and long-term patient care. A total of 83 pediatric patients with BRRS were identified. The most common clinical findings were macrocephaly (77%) and developmental disorders (63%). Surgical interventions were the treatment of choice, described in 19 articles. Patient surveillance was proposed in 15 case reports and mostly aimed at periodic cancer screening. Recognition of BRRS clinical symptoms and early referral to a geneticist is important for better disease control and overall prognosis. As targeted treatment is still lacking, symptom relief and long-term surveillance remain the main management strategies.

Sirolimus for vascular anomalies associated with PTEN hamartoma tumor syndrome.

Phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) is a rare condition associated with vascular anomalies and increased tumor risk. Sirolimus, an mTOR inhibitor used for managing vascular anomalies is underexplored in PHTS. A single-institution retrospective review of children with PHTS and vascular anomalies treated with sirolimus identified seven patients. Median age at sirolimus initiation was 10years. After a median 2.5-year follow-up, six of seven patients (86%) showed significant clinical improvement. No significant adverse effects were observed, except mild buccal ulcers and acne. This study supports sirolimus as an effective and safe treatment for vascular anomalies in a small group of children with PHTS.

Potentiation by Protein Synthesis Inducers of Translational Readthrough of Pathogenic Premature Termination Codons in PTEN Isoforms.

The PTEN tumor suppressor is frequently targeted in tumors and patients with PTEN hamartoma tumor syndrome (PHTS) through nonsense mutations generating premature termination codons (PTC) that may cause the translation of truncated non-functional PTEN proteins. We have previously described a global analysis of the readthrough reconstitution of the protein translation and function of the human canonical PTEN isoform by aminoglycosides. Here, we report the efficient functional readthrough reconstitution of the PTEN translational isoform PTEN-L, which displays a minimal number of PTC in its specific N-terminal extension in association with disease. We illustrate the importance of the specific PTC and its nucleotide proximal sequence for optimal readthrough and show that the more frequent human PTEN PTC variants and their mouse PTEN PTC equivalents display similar patterns of readthrough efficiency. The heterogeneous readthrough response of the different PTEN PTC variants was independent of the length of the PTEN protein being reconstituted, and we found a correlation between the amount of PTEN protein being synthesized and the PTEN readthrough efficiency. Furthermore, combination of aminoglycosides and protein synthesis inducers increased the readthrough response of specific PTEN PTC. Our results provide insights with which to improve the functional reconstitution of human-disease-related PTC pathogenic variants from PTEN isoforms by increasing protein synthesis coupled to translational readthrough.

Experience in a PHTS Expertise Centre: Yield of Thyroid Ultrasound Surveillance in Children with PTEN Hamartoma Tumor Syndrome.

Children with PTEN hamartoma tumor syndrome (PHTS) are at increased risk for developing thyroid abnormalities, including differentiated thyroid carcinoma (DTC). The Dutch PHTS guideline recommends ultrasound surveillance starting from age 18. Since the literature describes PHTS patients who developed DTC before age 18, the Dutch PHTS expertise centre has initiated annual ultrasound surveillance starting from age 12. The purpose of this study was to identify the yield of thyroid ultrasound surveillance in children. A retrospective single centre cohort study was conducted. Pediatric PHTS patients who received thyroid ultrasound surveillance before age 18 between 2016-2023 were included. Patients' medical records have been reviewed. Primary outcomes included prevalence and time to develop thyroid nodules ≥10mm, nodular growth, goiter, thyroiditis and DTC. Descriptive statistics and Kaplan-Meier analyses were performed. Forty-three patients were included. Two patients (5%) were diagnosed with DTC at ages 12 and 17. Both DTCs were identified as minimally invasive follicular carcinoma at stages pT3NxMx and pT1NxMx respectively. A total of 84% were diagnosed with thyroid abnormalities at a median age of 12 years (range 9-18). Most common findings were benign, including nodular disease (74%), goiter (30%) and autoimmune thyroiditis (12%). Nodular growth was observed in 14 patients (33%) resulting in (hemi)thyroidectomy in 7 patients (16%). Thyroid ultrasound surveillance resulted in the detection of DTC in 2/43 PHTS patients before age 18. These findings support the recommendation to initiate thyroid ultrasound surveillance in children at least from age 12, preferably within an expertise centre.

Increased frequency of infections and autoimmune disease in adults with PTEN Hamartoma Tumour Syndrome

There are indications for immune dysregulation in PTEN Hamartoma Tumour Syndrome (PHTS), however information on the clinical immune phenotype is lacking. We aimed to assess the frequency of infections and autoimmune disease in PHTS patients. A retrospective cohort study including 81 paediatric and 109 adult PHTS patients and 73 female adult controls and self-reported data from yearly surveillance visits. Differences between adult patients and controls were assessed with odds ratios (OR). Of paediatric patients, 1% reported fungal infections, 23% tonsillectomy/adenoidectomy, 36% bacterial infections requiring antibiotics, and 2% autoimmune disease. Of adult patients, up to 67% repeatedly reported fungal infections, and 73% was ever affected which was similar to controls. Compared to controls, adult patients more often reported (signs of) viral infections: tonsillectomy/adenoidectomy (78%; OR = 7.4 (95%CI: 3.7–15.8)), frequent infections during childhood (43%; OR = 2.5 (95%CI: 1.3–5.2)), and flu or cold infections more often than others (49%; OR = 3.9 (95%CI: 2.0–8.0)). Autoimmune disease was also more frequent (24%, OR = 2.7 (95%CI: 1.1–7.3)) in adult patients, and antibiotics use (38%, OR = 4.7 (95%CI: 1.3–23.0)) in female adult patients. PHTS patients experience a broad clinical phenotype of immune dysregulation. At adult age, this consists of more often viral and bacterial infections and autoimmune disease, and repetitive fungal infections.

Can thyroid histomorphology identify patients with PTEN hamartoma tumour syndrome?

The phosphatase and tensin homologue (PTEN) hamartoma tumour syndrome (PHTS) is a genetic disorder with variable clinical presentation and increased lifetime risk of multiorgan malignancies. The thyroid gland is commonly affected with follicular nodular disease (FND) and follicular cell-derived carcinomas. Histopathological and immunohistochemical assessment of thyroid disease in PHTS is essential to identify patients at-risk. In all, 30 PHTS patients with available thyroidectomy specimen material (2000-2023) and 31 control patients with FND and "adenomatous nodules" were retrieved. Histologic criteria, including the frequency of adenomatous-type nodules versus hyperplastic-type nodules, background and nodular lipomatous metaplasia, chronic lymphocytic thyroiditis, cytoplasmic clearing of follicular cells in nodules, nodule-in-nodule appearance, and spectrum of nuclear atypia between nodules were evaluated in both cohorts and a Thyroid Histomorphologic PHTS Score (THiPS) system was established with a cutoff of 4 points or higher being considered concerning for PHTS. In all, 27 PHTS (90%) and five control (16.1%) cases had THiPS ≥4. A PTEN immunohistochemical stain was evaluated in 25 cases of each cohort and showed nuclear and cytoplasmic loss of expression in all or most of the nodules of 24/25 PHTS cases. In 3/25 control cases, two with THiPS ≥4, had loss of expression in one to multiple nodules. Conventional papillary thyroid carcinomas in PHTS patients retained PTEN cytoplasmic expression. Our study supports that, although not specific, the finding of multiple histologic features is found more frequently in patients with PHTS compared to the non-PHTS control group. The THiPS system has high sensitivity for thyroid specimens from patients with PHTS.

Histopathological phenotyping of cancers in PTEN Hamartoma Tumor Syndrome for improved recognition: A single-center study.

PTEN hamartoma tumor syndrome (PHTS) has a broad clinical spectrum including various benign and malignant tumors at varying age of diagnosis. Many patients remain unrecognized, unaware of their increased cancer risk. We aimed to describe the cancer spectrum, age of onset and histopathological cancer characteristics to assess whether specific cancer characteristics could improve PHTS recognition. Genetic testing results and pathology reports were collected for patients tested for germline PTEN variants between 1997 and 2020 from the diagnostic laboratory and the Dutch nationwide pathology databank (Palga). The cancer spectrum and age of onset were assessed in patients with (PTENpos) and without (PTENneg) a germline PTEN variant. Histopathological cancer characteristics were assessed in a nested cohort. 341 PTENpos patients (56% females) and 2882 PTENneg patients (66% females) were included. PTENpos patients presented mostly with female breast (BC, 30%), endometrial (EC, 6%), thyroid (TC, 4%) or colorectal cancer (4%). PTENpos were significantly younger at cancer onset (43 vs. 47 years) and had more often (46% vs. 18%) a second BC than PTENneg. PTEN detection rates were highest for BC <40 years (9%), TC <20 years (15%) and EC <50 years (28%), and dropped to 6%, 4%, and 15% by age 60. Histopathological characteristics were similar between groups. No histopathological cancer characteristics were distinctive for PHTS. However, PTENpos were significantly younger at cancer onset. Therefore early-onset BC, EC, or TC warrants consideration of PHTS diagnostics either through a pre-screen for other PHTS features or direct germline testing.

Neuropsychological functioning of adults with PTEN hamartoma tumor syndrome.

PTEN hamartoma tumor syndrome (PHTS) might be associated with a distinct cognitive and psychological profile. However, previous studies are limited, predominantly based on small and pediatric cohorts, likely affected by selection bias, and show a broad range of findings. We aimed to characterize the neuropsychological functioning of adults with PHTS. A total of 40 participants, with intellectual disability as exclusion criterium, completed an extensive clinical neuropsychological assessment including cognitive tasks, questionnaires, and a clinical diagnostic interview. The cognitive tasks and questionnaire data were categorized as below and above average based on 1.5 SD. About 80% of participants showed an average level of intelligence. In addition, 30% and 24% of participants scored below average on immediate memory recall and speed of information processing, respectively. Furthermore, about 25% reported above average scores on the majority of the questionnaires, indicating psychological distress, signs of alexithymia, and cognitive complaints. Personality of participants was characterized by inflexibility, social withdrawal, and difficulties in recognizing and describing their own emotions. Adults with PHTS demonstrate a heterogeneous yet distinct neuropsychological profile that is characterized by slower information processing, psychological problems, and specific personality traits. These findings provide directions on how to optimize the care and daily lives of adults with PHTS.

Facial Features of Hereditary Cancer Predisposition.

In the age of telehealth medicine, an individual's facial features may provide the only physical clues signaling the presence of a heritable cancer predisposition syndrome. These syndromes include APC-associated polyposis, Birt-Hogg-Dubé syndrome, CYLD cutaneous syndrome, hereditary leiomyomatosis and renal cell cancer, multiple endocrine neoplasia, neurofibromatosis type 1, Peutz-Jeghers syndrome, PTEN hamartoma tumor syndrome, and tuberous sclerosis complex 1 and 2, among others. Correctly identifying characteristic features is important for genetic and nongenetic specialists as early detection can enable prompt intervention, improving patient outcomes. Advancements in the availability of genetic testing allow patients and their relatives to have more information about their genetic risk profile than before. These changes in clinical pathways, combined with improvements in screening and risk-reducing treatment, highlight the need to outline the cutaneous and morphologic features of high-risk cancer syndromes for clinicians. In this review, we describe the important facial features of hereditary cancer predisposition, with emphasis on diagnosis, cutaneous and extracutaneous manifestations, and screening.

Exploring the Prevalence of Oral Features for Early Detection of PTEN Hamartoma Tumour Syndrome

AimsPatients with PTEN hamartoma tumour syndrome (PHTS) have an increased risk of developing cancer due to a pathogenic germline variant in the PTEN tumour suppressor gene. Early recognition of PHTS facilitates initiation of cancer surveillance which is highly effective in preventing the development of advanced malignancies. PHTS is rare and due to its varied phenotype, even within families, oral abnormalities may be a valuable tool in the identification of these patients at an early stage before cancer development. Materials and methodsBetween 1997 and 2020, phenotypic characteristics were evaluated in 81 paediatric (median age: 9 years) and 86 adult (median age: 40 years) PHTS patients by one of 2 medical experts during yearly surveillance visits at a Dutch PHTS expertise centre. Oral features evaluated included gingival hypertrophy, oral papillomas, and high palate (in adults). ResultsWithin adults, gingival hypertrophy was present in 94%, oral papillomas in 88%, and a high palate in 89%. All adult patients had at least one of these oral features, and 99% showed at least 2 oral features. Oral features were less common in paediatric patients, especially under 11 years of age. Gingival hypertrophy was observed in 44% and oral papillomas in 54% of paediatric patients. ConclusionsThe presence of 2 or 3 oral features may indicate PHTS in adults or adolescents, especially if macrocephaly is present. Dental professionals are well-positioned to recognise these oral manifestations could be related to PHTS. They can initiate an overall clinical assessment of the patient by alerting the patient's medical practitioner of the findings and the possible need for genetic testing. This could significantly improve outcomes, including life expectancy, for patients and possibly for their relatives. Clinical relevanceDental professionals are ideally placed to recognise oral features and initiate early assessment of PHTS which could significantly improve patient outcomes.

PTEN Hamartoma Tumor Syndrome Presenting with a Rare Phenotype of Hemimegalencephaly and Intractable Epilepsy (P9-8.004)

PTEN Hamartoma Tumor Syndrome Presenting with a Rare Phenotype of Hemimegalencephaly and Intractable Epilepsy (P9-8.004)

Developmental and behavioral phenotypes of pediatric patients with PTEN hamartoma tumor syndrome.

Our study characterized the neurodevelopmental spectrum of individuals with PTEN Hamartoma Tumor Syndrome (PHTS), a syndrome that predisposes to both neurodevelopmental phenotypes and cancer risk. We aim to better understand life-impacting neurodevelopmental features of PHTS. Our study recruited 20 children/adolescents with PHTS, who were then administered assessments for autism spectrum disorder (ASD) and other neurocognitive measures, including assessment of IQ, executive and adaptive functioning, and health-related quality of life. Thirteen individuals (65%) were identified as having ASD, of which five were newly diagnosed during the study. Of those, ASD symptom severity was in the mild-moderate range for 77%. Overall, IQ was in the average range, with a mean of 92.61 (SD 24.45, p = 0.5), though there was a non-statistically significant trend toward individuals without ASD having a higher mean IQ (102.7 vs 82.3; p = 0.1). Subjects had significant impairment in processing speed (mean 75.38, SD 24.75, p < 0.05), decreased adaptive functioning skills across all domains, and a trend toward having more executive functioning problems. Individuals with PHTS are at increased risk of neurodevelopmental disorders, including ASD and impaired executive and adaptive functioning. Although clear guidelines exist for cancer surveillance for individuals with PHTS, additional guidelines and screening for neurodevelopmental disorders are warranted.