Five additional Costello syndrome patients with rhabdomyosarcoma: proposal for a tumor screening protocol

Cancer incidence and surveillance strategies in individuals with RASopathies

RASopathies are a set of clinical syndromes that have molecular and clinical overlap. Genetically, these syndromes are defined by germline pathogenic variants in RAS/MAPK pathway genes resulting in activation of this pathway. Clinically, their common molecular signature leads to comparable phenotypes, including cardiac anomalies, neurologic disorders and notably, elevated cancer risk. Cancer risk in individuals with RASopathies has been estimated from retrospective reviews and cohort studies. For example, in Costello syndrome, cancer incidence is significantly elevated over the general population, largely due to solid tumors. In some forms of Noonan syndrome, cancer risk is also elevated over the general population and is enriched for hematologic malignancies. Thus, cancer surveillance guidelines have been developed to monitor for the occurrence of such cancers in individuals with some RASopathies. These include abdominal ultrasound and urinalyses for individuals with Costello syndrome, while complete blood counts and splenic examination are recommended in Noonan syndrome. Improved cancer risk estimates and refinement of surveillance recommendations will improve the care of individuals with RASopathies.

Cutaneous mosaic RASopathies associated with rhabdomyosarcoma

Variants in RAS are known drivers of certain pediatric blood and solid cancers, including brain tumors. Though most RAS-driven cancers are thought to occur sporadically, genetic syndromes caused by germline RAS variants portend a slightly higher risk of rhabdomyosarcoma (RMS) development. Three new cases and a review of the literature demonstrate that in rare cases, certain somatic RAS variants are associated with an increased risk of RMS and that RMS development may be heralded by the presence of concomitant RAS-driven birthmarks. Further prospective studies are needed to establish incidence and recommend appropriate monitoring guidelines for patients at risk.

Hyperinsulinemic Hypoglycemia in a Patient with Costello Syndrome: An Etiology to Consider in Hypoglycemia

Several endocrine disorders have been defined in patients with Costello syndrome (CS). In this report, we describe a patient with CS accompanied by a clinical picture of hyperinsulinemic hypoglycemia responsive to diazoxide treatment. A 41-day-old female patient with a birth weight of 3,600 g was referred for atypical facial features and swallowing dysfunction. She had a weight of 4,000 g (-0.8 SDS), a length of 50 cm (-2.4 SDS), and a head circumference of 38 cm (0.2 SDS). The clinical findings were suggestive of a genetic syndrome, mainly a RASopathy or Beckwith-Wiedemann syndrome. Whole exome sequencing revealed a de novo heterozygous missense variant in the HRAS (NM_001130442) gene in exon 2: c.35G>C; p.(Gly12Ala), establishing the molecular diagnosis of CS. The patient developed symptomatic hypoglycemia (jitteriness and sweating) at the age of 13 months. The patient's serum glucose was 38 mg/dL with simultaneous serum insulin and C-peptide levels, 2.8 μIU/mL and 1.8 ng/mL, respectively. Hyperinsulinism was suspected, and an exaggerated glucose response was detected in a glucagon test. Blood glucose monitoring indicated episodes of fasting hypoglycemia and postprandial hyperglycemia. Diazoxide of 10 mg/kg/day was initiated in 3 doses for hyperinsulinemic hypoglycemia, which resolved without new episodes of postprandial hyperglycemia. The patient deceased at the age of 17 months due to cardiorespiratory failure in the course of severe pneumonia complicated with pulmonary hypertension and hypertrophic cardiomyopathy. Several genetic syndromes including CS are associated with endocrinologic manifestations including abnormal glucose homeostasis. Although the frequency and underlying mechanisms leading to hyperinsulinemic hypoglycemia are yet unknown, hypoglycemia in CS responds well to diazoxide.

Genetic Predisposition to Solid Pediatric Cancers

Progresses over the past years have extensively improved our capacity to use genome-scale analyses—including high-density genotyping and exome and genome sequencing—to identify the genetic basis of pediatric tumors. In particular, exome sequencing has contributed to the evidence that about 10% of children and adolescents with tumors have germline genetic variants associated with cancer predisposition. In this review, we provide an overview of genetic variations predisposing to solid pediatric tumors (medulloblastoma, ependymoma, astrocytoma, neuroblastoma, retinoblastoma, Wilms tumor, osteosarcoma, rhabdomyosarcoma, and Ewing sarcoma) and outline the biological processes affected by the involved mutated genes. A careful description of the genetic basis underlying a large number of syndromes associated with an increased risk of pediatric cancer is also reported. We place particular emphasis on the emerging view that interactions between germline and somatic alterations are a key determinant of cancer development. We propose future research directions, which focus on the biological function of pediatric risk alleles and on the potential links between the germline genome and somatic changes. Finally, the importance of developing new molecular diagnostic tests including all the identified risk germline mutations and of considering the genetic predisposition in screening tests and novel therapies is emphasized.

Germline predisposition to genitourinary rhabdomyosarcoma

Multiple genetic conditions predispose to the development of rhabdomyosarcoma. Much of the literature on rhabdomyosarcoma in genetic syndromes does not sub-divide the location or the pathology of the sarcomas. Therefore, there are limited data on genitourinary specific associations with certain genetic syndromes. We summarize, here, the primary differential considerations for rhabdomyosarcoma of the genitourinary system. Primary considerations include DICER1 pathogenic variation, Li-Fraumeni syndrome, constitutional mismatch repair deficiency, mosaic variegated aneuploidy, neurofibromatosis type 1, Noonan syndrome, other RASopathies, Costello syndrome, and Beckwith-Wiedemann syndrome. Some conditions may present with specific pathological, clinical and/or family history features, but for others, the genitourinary tumor may be the only presenting sign at the time of diagnosis. Genetic evaluation with counseling and/or testing may help identify an underlying tumor predisposition. This manuscript serves as an introduction to germline considerations for children with genitourinary rhabdomyosarcoma.

Significantly greater prevalence of DICER1 alterations in uterine embryonal rhabdomyosarcoma compared to adenosarcoma

Embryonal rhabdomyosarcomas (ERMS) account for 2-3% of cancers in pediatric and adolescent populations. They are rarer in adults. We and others have reported that ERMS arising in the uterine cervix may harbor mutations in the gene encoding the microRNA biogenesis enzyme, DICER1, but a large series of cases has not been published. In the uterus, distinguishing ERMS from adenosarcoma can be very challenging, even for expert pathologists, and DICER1 alterations have been identified in a variable subset of uterine adenosarcomas. We hypothesized that DICER1 genetic testing may be useful in distinguishing between ERMS and adenosarcoma. We conducted a central pathology review-based study of 64 tumors initially thought to be uterine ERMS or adenosarcoma; 19 neoplasms had a consensus diagnosis of ERMS, 27 of adenosarcoma and for 18, no consensus diagnosis was reached. The median age at diagnosis was 30 years (range 2.5-69) for ERMS, 57.5 years (range 27-82) for adenosarcoma, and 65.5 years (range 32-86) for no consensus cases. In our series, the DICER1 mutation prevalence differed between the three groups: DICER1 alterations were present in 18/19 (95%) ERMS, 7/27 (26%) adenosarcomas (p < 0.001), and 4/18 (22%) no consensus cases. A germline alteration was present in 6/12 ERMS patients tested versus 0/6 adenosarcoma patients. Thus, although DICER1 mutations are near ubiquitous in uterine ERMS and are significantly less common in uterine adenosarcoma, DICER1 testing is only of value in distinguishing between the two neoplasms when a DICER1 mutation is absent, as this is helpful in excluding ERMS. On review of the clinical and radiological features of the single DICER1 wild-type cervical ERMS, this was thought most likely to be of vaginal origin. Given the significant prevalence of DICER1 germline pathogenic variants in uterine ERMS, all patients with this diagnosis should be referred to a genetics service.

Advancing RAS/RASopathy therapies: An NCI-sponsored intramural and extramural collaboration for the study of RASopathies

RASopathies caused by germline pathogenic variants in genes that encode RAS pathway proteins. These disorders include neurofibromatosis type 1 (NF1), Noonan syndrome (NS), cardiofaciocutaneous syndrome (CFC), and Costello syndrome (CS), and others. RASopathies are characterized by heterogenous manifestations, including congenital heart disease, failure to thrive, and increased risk of cancers. Previous work led by the NCI Pediatric Oncology Branch has altered the natural course of one of the key manifestations of the RASopathy NF1. Through the conduct of a longitudinal cohort study and early phase clinical trials, the MEK inhibitor selumetinib was identified as the first active therapy for the NF1-related peripheral nerve sheath tumors called plexiform neurofibromas (PNs). As a result, selumetinib was granted breakthrough therapy designation by the FDA for the treatment of PN. Other RASopathy manifestations may also benefit from RAS targeted therapies. The overall goal of Advancing RAS/RASopathy Therapies (ART), a new NCI initiative, is to develop effective therapies and prevention strategies for the clinical manifestations of the non-NF1 RASopathies and for tumors characterized by somatic RAS mutations. This report reflects discussions from a February 2019 initiation meeting for this project, which had broad international collaboration from basic and clinical researchers and patient advocates.

Recombinant GH treatment in a case of Costello syndrome with a 5-year follow-up

Costello syndrome (CS) is a rare member of the group of neuro-cardio-facio-cutaneous diseases known as RASopathies. CS involves characteristic dysmorphic craniofacial features, cardiac defects, and increased cancer susceptibility, depending on the heterozygous activating germline mutations in HRAS. Polyhydramnios and high birth weight are the most common presentations in the perinatal and neonatal periods; while poor postnatal growth, short stature, and failure to thrive are significant issues in infancy. Possible mechanisms of short stature in CS include GH deficiency and feeding difficulties. Only a few reported cases of CS with GH deficiency exist in literature. Here, we describe the 5-yr follow-up of a CS patient with complete GH deficiency treated with recombinant human GH (rhGH) from the age of four years. No significant adverse events regarding progression of hypertrophic cardiomyopathy and tumor development were observed. She has been responsive to treatment with improved growth velocity and height standard deviation scores. She is still under continuous monitoring for concerns on the possible development of cardiac events and malignancies. This case indicated that rhGH therapy is effective for improving the height and growth velocity of CS patients with GH deficiency under close cardiac and oncological monitoring.

The impact of RASopathy-associated mutations on CNS development in mice and humans

The RAS signaling pathway is involved in the regulation of developmental processes, including cell growth, proliferation, and differentiation, in the central nervous system (CNS). Germline mutations in the RAS signaling pathway genes are associated with a group of neurodevelopmental disorders, collectively called RASopathy, which includes neurofibromatosis type 1, Noonan syndrome, cardio-facio-cutaneous syndrome, and Costello syndrome. Most mutations associated with RASopathies increase the activity of the RAS-ERK signaling pathway, and therefore, most individuals with RASopathies share common phenotypes, such as a short stature, heart defects, facial abnormalities, and cognitive impairments, which are often accompanied by abnormal CNS development. Recent studies using mouse models of RASopathies demonstrated that particular mutations associated with each disorder disrupt CNS development in a mutation-specific manner. Here, we reviewed the recent literatures that investigated the developmental role of RASopathy-associated mutations using mutant mice, which provided insights into the specific contribution of RAS-ERK signaling molecules to CNS development and the subsequent impact on cognitive function in adult mice.

Medically actionable comorbidities in adults with Costello syndrome

Costello syndrome (CS) is an autosomal-dominant condition caused by activating missense mutations in HRAS. There is little literature describing health concerns specific to adults with CS. Parents of individuals with CS need to know what to anticipate as their children age. We surveyed a group of 20 adults and older adolescents with CS regarding their medical concerns and lifestyle characteristics. We identified several previously undescribed actionable medical concerns in adults with CS. First, the high prevalence of anxiety in this cohort indicates that screening for anxiety is warranted since this is a treatable condition that can have a significant impact on quality of life. Second, adults with CS should be monitored for progressive contractures or other problems that could decrease mobility. This is especially important in a population that seems to have increased risk for osteopenia. Finally, the lack of cancer diagnoses in adulthood is of interest, although the cohort is too small to draw definitive conclusions about cancer risk in adults with CS. Ongoing follow-up of the current cohort of adults with CS is necessary to delineate progressive medical and physical problems, which is essential for providing targeted management recommendations and anticipatory guidance to families.

Costello syndrome: Clinical phenotype, genotype, and management guidelines

Costello syndrome (CS) is a RASopathy caused by activating germline mutations in HRAS. Due to ubiquitous HRAS gene expression, CS affects multiple organ systems and individuals are predisposed to cancer. Individuals with CS may have distinctive craniofacial features, cardiac anomalies, growth and developmental delays, as well as dermatological, orthopedic, ocular, and neurological issues; however, considerable overlap with other RASopathies exists. Medical evaluation requires an understanding of the multifaceted phenotype. Subspecialists may have limited experience in caring for these individuals because of the rarity of CS. Furthermore, the phenotypic presentation may vary with the underlying genotype. These guidelines were developed by an interdisciplinary team of experts in order to encourage timely health care practices and provide medical management guidelines for the primary and specialty care provider, as well as for the families and affected individuals across their lifespan. These guidelines are based on expert opinion and do not represent evidence-based guidelines due to the lack of data for this rare condition.

Phenotypic and Genetic Characteristics of Five Korean Patients with Costello Syndrome

Costello syndrome (CS) is a rare genetic disorder characterized by distinctive facial appearance, cardiopulmonary complications, severe growth retardation, skin and skeletal defects, developmental delay, and tumor predisposition. CS is caused by heterozygous de novo mutations in the proto-oncogene HRAS, which is a component of the RAS/mitogen-activated protein kinase pathway. Herein, we reviewed the phenotypic and genetic features of 5 Korean patients who were genetically diagnosed with CS. Atrial tachycardia and polyhydramnios, which are important prenatal features for CS, were observed in 4 and 5 patients, respectively. The distinctive coarse facial appearances of the patients and presence of deep palmoplantar creases supported the clinical diagnosis of CS, which was confirmed by HRAS sequence analysis. Extremely poor postnatal growth was observed in all 5 patients. Further, all patients exhibited cardiac abnormalities; left ventricular hypertrophy and hypertrophic cardiomyopathy were observed in 3 patients. All 5 patients suffered from airway problems; 3 of them required intubation right after birth, and 2 of them received tracheostomy. One patient with a p.Gly12Ser mutation was diagnosed with retroperitoneal rhabdomyosarcoma alveolar type at the age of 5 years. Consistent with previous reports, both patients with p.Gly12Cys mutations died within the first year of life due to cardiopulmonary failure. Our study summarizes the characteristics of these 5 Korean patients with CS and, along with previous studies, provides clues for genotype-phenotype correlation in patients with CS.

A case of woolly hair nevus, multiple linear pigmentation, and epidermal nevi with somatic HRAS p.G12S mutation

Woolly hair nevus is a rare syndrome that presents as woolly hair in restricted areas of the scalp and may be associated with pigmented macules or epidermal nevus on the body. Here, we report a case of woolly hair nevus, linear pigmentation, and multiple epidermal nevi with a somatic HRAS c.34G>A(p.G12S) mutation.

Craniofacial and cutaneous findings in Noonan, Costello and LEOPARD syndromes

Noonan, Costello and LEOPARD syndromes belong to a family of cardiofaciocutaneous disorders and share common genetic traits. As they are associated with a germline mutation in genes encoding proteins involved in RAS/MAPK, patients suffering from these syndromes are at a greater risk of cancer and abnormal myelopoiesis in infancy. Patients with cardio faciocutaneous syndromes share some clinically overlapping syndromes, therefore differential diagnosis can be problematic. In this paper we aim at demonstrating distinctive craniofacial and cutaneous manifestations of Noonan, Costello and LEOPARD syndromes which can be useful for clinicians who aim at treatment of children with rare diseases.

Consequences of diagnosing a tumor predisposition syndrome in children with cancer: A literature review

Up to 8.5% of children with cancer have a genetic cause for their cancer: a tumor predisposition syndrome (TPS). Diagnosing a TPS is of great importance, as it may have major consequences for clinical care. Patients with TPSs require specific monitoring and management. We present an overview of the cancer-related and noncancer-related consequences for the 36 most common TPSs.

Cytotoxicity of Zardaverine in Embryonal Rhabdomyosarcoma from a Costello Syndrome Patient

Costello syndrome (CS) patients suffer from a very high 10% incidence of embryonal rhabdomyosarcoma (ERMS). As tools to discover targeted therapeutic leads, we used a CS patient-derived ERMS cell line (CS242 ERMS) harboring a homozygous p.G12A mutation in HRAS, and a control cell line derived from the same patient comprising non-malignant CS242 fibroblasts with a heterozygous p.G12A HRAS mutation. A library of 2,000 compounds with known pharmacological activities was screened for their effect on CS242 ERMS cell viability. Follow-up testing in a panel of cell lines revealed that various compounds originally developed for other indications were remarkably selective; notably, the phosphodiesterase (PDE) inhibitor zardaverine was at least 1,000-fold more potent in CS242 ERMS than in the patient-matched non-malignant CS242 fibroblasts, other ERMS, or normal fibroblasts. Chronic treatment with zardaverine led to the emergence of resistant cells, consistent with CS242 ERMS comprising a mixed population of cells. Many PDE inhibitors in addition to zardaverine were tested on CS242 ERMS, but almost all had no effect. Interestingly, zardaverine and analogs showed a similar cytotoxicity profile in CS242 ERMS and cervical carcinoma-derived HeLa cells, suggesting a mechanism of action common to both cell types that does not require the presence of an HRAS mutation (HeLa contains wild type HRAS). Two recent studies presented possible mechanistic explanations for the cytotoxicity of zardaverine in HeLa cells. One revealed that zardaverine inhibited a HeLa cell-based screen measuring glucocorticoid receptor (GR) activation; however, using engineered HeLa cells, we ruled out a specific effect of zardaverine on signaling through the GR. The second attributed zardaverine toxicity in HeLa cells to promotion of the interaction of phosphodiesterase 3A and the growth regulatory protein Schlafen 12. We speculate that this work may provide a possible mechanism for zardaverine action in CS242 ERMS, although we have not yet tested this hypothesis. In conclusion, we have identified zardaverine as a potent cytotoxic agent in a CS-derived ERMS cell line and in HeLa. Although we have ruled out some possibilities, the mechanism of action of zardaverine in CS242 ERMS remains to be determined.

A Comprehensive Review of Pediatric Tumors and Associated Cancer Predisposition Syndromes

An understanding of the role of inherited cancer predisposition syndromes in pediatric tumor diagnoses continues to develop as more information is learned through the application of genomic technology. Identifying patients and their relatives at an increased risk for developing cancer is an important step in the care of this patient population. The purpose of this review is to highlight various tumor types that arise in the pediatric population and the cancer predisposition syndromes associated with those tumors. The review serves as a guide for recognizing genes and conditions to consider when a pediatric cancer referral presents to the genetics clinic.

Childhood cancer predisposition syndromes-A concise review and recommendations by the Cancer Predisposition Working Group of the Society for Pediatric Oncology and Hematology

Heritable predisposition is an important cause of cancer in children and adolescents. Although a large number of cancer predisposition genes and their associated syndromes and malignancies have already been described, it appears likely that there are more pediatric cancer patients in whom heritable cancer predisposition syndromes have yet to be recognized. In a consensus meeting in the beginning of 2016, we convened experts in Human Genetics and Pediatric Hematology/Oncology to review the available data, to categorize the large amount of information, and to develop recommendations regarding when a cancer predisposition syndrome should be suspected in a young oncology patient. This review summarizes the current knowledge of cancer predisposition syndromes in pediatric oncology and provides essential information on clinical situations in which a childhood cancer predisposition syndrome should be suspected.

Costello Syndrome and Umbilical Ligament Rhabdomyosarcoma in Two Pediatric Patients: Case Reports and Review of the Literature

Costello syndrome is caused by heterozygous de novo missense mutations in the protooncogene HRAS with tumor predisposition, especially rhabdomyosarcoma. We here report two pediatric patients with Costello syndrome and umbilical ligament rhabdomyosarcoma. A review of the literature published in English in MEDLINE from January 1971 to June 2016 using the search terms “Costello syndrome” and “rhabdomyosarcoma” was performed, including two new cases that we describe. Twenty-six patients with Costello syndrome and rhabdomyosarcoma were recorded with mean age of diagnosis of 2 years and 8 months. The most common tumor location was the abdomen/pelvis, including four out of ten of those in the umbilical ligament. The most common histological subtype was embryonal rhabdomyosarcoma. Overall survival was 43%. A total of 17 rhabdomyosarcomas in pediatric patients arising in the umbilical ligament were recorded with mean age of diagnosis of 3 years and 4 months. Overall survival was 69%. Costello syndrome is a poorly known disorder in pediatric oncology but their predisposition to malignancies implies the need for a new perspective on early diagnosis and aggressive medical and surgical treatment.

Novel pathogenic variant in the HRAS gene with lethal outcome and a broad phenotypic spectrum among Polish patients with Costello syndrome

Costello syndrome (CS) is a rare congenital disorder from the group of RASopathies, characterized by a distinctive facial appearance, failure to thrive, cardiac and skin anomalies, intellectual disability, and a predisposition to neoplasia. CS is associated with germline mutations in the proto-oncogene HRAS, a small GTPase from the Ras family. In this study, a molecular and clinical analysis was carried out in eight Polish patients with the Costello phenotype. A molecular test showed two known heterozygous mutations in the first coding exon of the gene in seven patients: p.G12S (n=4) and p.G12A (n=3), and a novel pathogenic variant p.G60V in one child with an unusually severe, lethal course of the syndrome. In addition, a fatal course of CS was present in one patient with the p.G12A mutation and in another with p.G12S, there was a co-occurrence of Turner syndrome because of the distal Xp deletion. A severe clinical manifestation with a lethal outcome in an individual with p.G60V in HRAS and contrary observations of an attenuated phenotype in CS patients with other mutations at glycine-60 residue may suggest that the nature of the substituted amino acid plays a significant role in the clinical variability observed in some CS cases.

Primary rhabdomyosarcoma of the distal femoral diaphysis: a case report and review of the literature

Primary rhabdomyosarcoma of the bone is an extremely rare condition with few examples reported in the literature. We present the case of a 34-year-old male who presented with a lesion in the distal femur with initial imaging features consistent with Ewing sarcoma. Histologically, the lesion consisted of atypical pleomorphic polygonal rhabdomyoblasts demonstrating focal desmin and myogenin expression. A diagnosis of pleomorphic rhabdomyosarcoma was rendered. Despite systemic treatment and surgery, this patient experienced a rapidly progressive disease course. We believe this is only the second report in the orthopedic literature of a case of primary pleomorphic rhabdomyosarcoma of the bone. The key imaging, pathologic, and clinical findings are discussed.

A clinicopathologic study of head and neck rhabdomyosarcomas showing FOXO1 fusion-positive alveolar and MYOD1-mutant sclerosing are associated with unfavorable outcome

BACKGROUND

Based on their distinctive histologic and genetic features, the latest WHO classification of soft tissue tumors includes four pathologic variants of rhabdomyosarcoma (RMS): embryonal (ERMS), alveolar (ARMS), spindle cell-sclerosing (SRMS-ScRMS) and pleomorphic RMS. The aim of this study focused on a detailed clinicopathologic and survival analysis of head and neck RMS (HNRMS) using the latest pathologic and molecular criteria reflecting this new subclassification in a large cohort.

PATIENTS AND METHODS

Patients managed for HNRMS in our institution (1996-2015) were analyzed. The presence of a FOXO1 fusion was required for the classification of ARMS. MYOD1 mutations in SRMS-ScRMS were tested when material available. Univariate and multivariate analyses were performed to evaluate variables related to overall survival (OS).

RESULTS

Ninety-nine HNRMS patients (52 males and 47 females, mean of 16years) were included in the study after pathologic re-review. The most common location was parameningeal (PM) (n=64), followed by non-orbital/non-PM (n=25) and orbital (n=10). There were 53 ERMS, 33 fusion-positive ARMS and 13 SRMS-ScRMS [SRMS (8); ScRMS (5)]. The 5-year OS rate for ERMS patients was significantly higher (82%) compared to ARMS (53%) and SRMS-ScRMS (50%) [SRMS (75%); ScRMS (30%)]. Univariate analysis showed that survival was dependent on histology (P=0.012), tumor size >5cm (P<0.001), regional lymph node involvement (P=0.002), metastasis at initial presentation (P<0.001), stage (P<0.001), and recurrence (P=0.002). Multivariate analysis confirmed histologic subtype to be significant (P=0.043).

CONCLUSION

Our findings reinforce that HNRMS is a heterogenous disease with ARMS and SRMS-ScRMS having an equally unfavorable outcome.

Recombinant growth hormone therapy in a girl with Costello syndrome: a 4-year observation

Background

Costello syndrome is a rare syndrome of multiple congenital anomalies. The typical clinical traits include dysmorphic craniofacial features, skin hyperpigmentation and excess, feeding difficulties leading to severe postnatal growth retardation, short stature, joint hypermobility, and delayed psychomotor development. Additionally, Costello syndrome may present with an increased incidence of congenital heart disease, hypertrophic cardiomyopathy, and increased risk of both benign and malignant tumors. Furthermore, cases of patients with endocrine disorders such as adrenal insufficiency and endogenous growth hormone deficiency have also been documented.

Case presentation

We present a patient with Costello syndrome who has been successfully treated with recombinant human growth hormone (rhGH) for almost 4 years.

Conclusions

The possibility of growth hormone (GH) treatment can be considered in cases of documented GH deficiency in patients with Costello syndrome, but only under close oncologic and cardiologic supervision.

Paternal uniparental disomy 11p15.5 in the pancreatic nodule of an infant with Costello syndrome: Shared mechanism for hyperinsulinemic hypoglycemia in neonates with Costello and Beckwith-Wiedemann syndrome and somatic loss of heterozygosity in Costello syndrome driving clonal expansion

Costello syndrome (CS) entails a cancer predisposition and is caused by activating HRAS mutations, typically arising de novo in the paternal germline. Hypoglycemia is common in CS neonates. A previously reported individual with the rare HRAS p.Gln22Lys had hyperinsulinemic hypoglycemia. Autopsy showed a discrete pancreatic nodule. The morphologic and immunohistochemistry findings, including loss of p57(Kip2) protein, were identical to a focal lesion of congenital hyperinsulinism, however, no KCNJ11 or ABCC8 mutation was identified and germline derived DNA showed no alternation of the maternal or paternal 11p15 alleles. Here we report paternal uniparental disomy (pUPD) within the lesion, similar to the pUPD11p15.5 in Beckwith-Wiedemann syndrome (BWS). The similar extent of the pUPD suggests a similar mechanism driving hyperinsulinemia in both conditions. After coincidental somatic LOH and pUPD, the growth promoting effects of the paternally derived HRAS mutation, in combination with the increased function of the adjacent paternally expressed IGF2, may together result in clonal expansion. Although this somatic LOH within pancreatic tissue resulted in hyperinsulinism, similar LOH in mesenchymal cells may drive embryonal rhabdomyosarcoma (ERMS). Interestingly, biallelic IGF2 expression has been linked to rhabdomyosarcoma tumorigenesis and pUPD11 occurred in all 8 ERMS samples from CS individuals. Somatic KRAS and HRAS mutations occur with comparable frequency in isolated malignancies. Yet, the malignancy risk in CS is notably higher than in Noonan syndrome with a KRAS mutation. It is conceivable that HRAS co-localization with IGF2 and the combined effect of pUPD 11p15.5 on both genes contributes to the oncogenic potential.

Costello syndrome: Analysis of the posterior cranial fossa in children with posterior fossa crowding

This study aimed to assess changes in the posterior cranial fossa (PCF) to shed light on the mechanism of cerebellar herniation in children with Costello syndrome (CS) and posterior fossa crowding. We performed a morphovolumetric PCF analysis on brain magnetic resonance imaging (MRI) in seven children with CS (mean age 31 ± 16 months) comparing the MRI scans with those of seven age-matched healthy subjects.PCF volume (PCFV), PCF brain volume (PCFBV) and cerebellar volume (CeV) were assessed on axial T2-weighted MRI. Morphometric parameters (diameters of the foramen magnum, tentorial angle, basiocciput, supraocciput, basisphenoid and exocciput lengths) were measured on sagittal T1-weighted MRI. The volume of the cerebrospinal fluid (CSF) spaces was calculated as PCFV minus PCFBV.Five out of seven CS children showed tonsillar herniation in the upper cervical canal; no child had hydrocephalus but three out of seven children showed ventriculomegaly. In addition, the PCFV/PCFBV ratio, PCFV, CSF spaces volume, basiocciput, basisphenoid and exocciput lengths and latero-lateral and antero-posterior diameters of the foramen magnum were significantly reduced, whereas no significant changes were found in supraocciput length, PCFBV, CeV or hindbrain volume. The volumetric reduction of the PCF due to bony posterior fossa hypoplasia is a predisposing factor for developing cerebellar tonsillar herniation through the foramen magnum in children with CS. The altered anatomy of the foramen magnum and upward expansion of the PCF secondary to an increased tentorial slope serves to explain the possible mechanism of cerebellar herniation in patients with CS.

Rhabdomyosarcomas in children with neurofibromatosis type I: A national historical cohort

BACKGROUND

Rhabdomyosarcoma (RMS) occasionally occurs in a context of a predisposition syndrome. The most common predisposition syndromes include germline TP53 mutations and constitutive alterations in RAS pathway activation, such as Costello syndrome, Noonan syndrome and neurofibromatosis type 1. We report a national retrospective series of 16 RMS occurring in neurofibromatosis type 1 (NF1) patients during childhood, within a 20-year period.

RESULTS

The mean age at diagnosis of the cancer was 2.5 years. All were embryonal subtype. Most tumours developed in the pelvis. One was metastatic. Chemotherapy and radiotherapy were normally scheduled without any specific toxicity. The 5-year event-free survival and overall survival were 67% and 87%, respectively. Long-term sequel related to chemotherapy consisted in two chronic tubulopathies, hence not obviously different from non-NF1 patients. No second cancer was reported so far with a median follow-up of 9.7 years. The genomic analysis performed on six samples revealed the abnormalities commonly observed in sporadic RMS: gain of chromosome 2 (5/6), 8 (6/6) and chromosome 11p loss of heterozygosity (5/6). Interestingly, we identified small deletions in tumour suppressor genes that may synergize with NF1 inactivation.

CONCLUSIONS

Patients with neurofibromatosis are prone to develop embryonal-type RMS that require the same treatment as sporadic cases.

Rhabdomyosarcoma of the head and neck in children

Rhabdomyosarcoma (RMS) is the most frequent soft tissue sarcoma in children. It is localized in the head and neck region in 40% of cases. Treatment of RMS is complex, including multi-drug chemotherapy, radiotherapy and surgery. The progress that has been accomplished in oncology in recent decades significantly improved outcomes. The 5-year survival rate raised from 25% in 1970 to 73% in 2001, according to IRS-IV data. The outcome is influenced by primary tumor localization, clinical staging, histological tumor type and age at the moment of diagnosis. The relatively rare incidence of these tumors resulted in difficulties in creating more standardized therapeutic protocols. Comparison of outcomes in large patients groups led to an increase in the number of patients with complete remission. Although survival rates of RMS patients have improved, searching for new therapeutic modalities and substances is still essential to improve outcomes in cases of more advanced stages and unfavorable tumor localizations.

Growth hormone replacement therapy in Costello syndrome

Costello syndrome (CS) is considered an overgrowth disorder given the macrosomia that is present at birth .However, shortly after birth the weight drops dramatically and the patients are usually referred for failure to thrive. Subsequently, affected patients develop the distinctive coarse facial appearance and are at risk for cardiac anomalies and solid tumor malignancies. Various endocrine disorders, although not very often, have been reported in patients with CS, including growth hormone deficiency, hypoglycemia, ACTH deficiency, cryptorchidism and hypothyroidism. We report a case of Costello syndrome with hypothyroidism, cryptorchidism and growth hormone deficiency and we evaluate the long-term safety and efficacy of growth hormone replacement therapy. The index patient is a paradigm of successful and safe treatment with growth hormone for almost 7 years. Since patients with CS are at increased risk for cardiac myopathy and tumor development they deserve close monitoring during treatment.

Perinatal features of the RASopathies: Noonan syndrome, cardiofaciocutaneous syndrome and Costello syndrome

The RASopathies are a family of developmental disorders caused by heritable defects of the RAS/MAPK signaling pathway. While the postnatal presentation of this group of disorders is well known, the prenatal and neonatal findings are less widely recognized. We report on the perinatal presentation of 10 patients with Noonan syndrome (NS), nine with Cardiofaciocutaneous syndrome (CFCS) and three with Costello syndrome (CS), in conjunction with the results of a comprehensive literature review. The majority of perinatal findings in NS, CS, and CFCS are shared: polyhydramnios; prematurity; lymphatic dysplasia; macrosomia; relative macrocephaly; respiratory distress; hypotonia, as well as cardiac and renal anomalies. In contrast, fetal arrhythmia and neonatal hypoglycemia are relatively specific to CS. NS, CS, and CFCS should all be considered as a possible diagnosis in pregnancies with a normal karyotype and ultrasound findings of a RASopathy. Recognition of the common perinatal findings of these disorders should facilitate both their prenatal and neonatal diagnosis.

Ras/MAPK syndromes and childhood hemato-oncological diseases

Noonan syndrome (NS) is an autosomal-dominant disease characterized by distinctive facial features, webbed neck, cardiac anomalies, short stature and cryptorchidism. NS exhibits phenotypic overlap with Costello syndrome and cardio-facio-cutaneous (CFC) syndrome. Germline mutations of genes encoding proteins in the RAS/mitogen-activated protein kinase (MAPK) pathway cause NS and related disorders. Germline mutations in PTPN11, KRAS, SOS1, RAF1, and NRAS have been identified in 60-80 % of NS patients. Germline mutations in HRAS have been identified in patients with Costello syndrome and mutations in KRAS, BRAF, and MAP2K1/2 (MEK1/2) have been identified in patients with CFC syndrome. Recently, mutations in SHOC2 and CBL have been identified in patients with Noonan-like syndrome. It has been suggested that these syndromes be comprehensively termed RAS/MAPK syndromes, or RASopathies. Molecular analysis is beneficial for the confirmation of clinical diagnoses and follow-up with patients using a tumor-screening protocol, as patients with NS and related disorders have an increased risk of developing tumors. In this review, we summarize the genetic mutations, clinical manifestations, associations with malignant tumors, and possible therapeutic approaches for these disorders.

Costello syndrome: a Ras/mitogen activated protein kinase pathway syndrome (rasopathy) resulting from HRAS germline mutations

Costello syndrome (OMIM# 218040) is a distinctive rare multisystem disorder comprising a characteristic coarse facial appearance, intellectual disabilities, and tumor predisposition. Although the diagnosis can be suspected clinically, confirmation requires identification of a heterozygous mutation in the proto-oncogene HRAS. In contrast to somatic oncogenic mutations in neoplasia, the Costello syndrome changes are typically introduced in the paternal germline. The predicted amino acid substitutions allow for constitutive or prolonged activation of the HRAS protein, resulting in dysregulation of the Ras/mitogen activated protein kinase pathway. Dysregulation of this signaling pathway is the disease mechanism shared among Costello syndrome and other rasopathies, including neurofibromatosis type 1, Noonan syndrome, cardio-facio-cutaneous syndrome, and Legius syndrome. The Ras/mitogen activated protein kinase pathway governs cell proliferation and differentiation, and its dysregulation affects cardiac and brain development, accounting for the significant overlap in physical and developmental differences and common medical problems among rasopathies. Unlike the genetically heterogeneous Noonan syndrome and cardio-facio-cutaneous syndrome, Costello syndrome is caused by HRAS mutations only. Patients, clinicians, and researchers may benefit from a multidisciplinary "rasopathy clinic," which serves patients with more common conditions such as Noonan syndrome and neurofibromatosis and those affected by rare conditions such as Costello syndrome.

RasGRF1 regulates proliferation and metastatic behavior of human alveolar rhabdomyosarcomas

The involvement of the Ras superfamily of GTPases in the pathogenesis of rhabdomysarcoma (RMS) is not well understood. While mutant H-Ras leads to embryonal RMS (ERMS) formation in experimental animals and in Costello syndrome patients, no data exists on the potential role of Ras GTPases in the pathogenesis of alveolar RMS (ARMS). To address this issue better, we focused on the role of the GTP exchange factor RasGRF1 in this process. We observed that, in comparison to normal skeletal muscle cells, RasGRF1 mRNA is upregulated in the majority of human ARMS cell lines and subsequently confirmed its high expression in patient samples. By employing confocal microscopy analysis, we observed RasGRF1 accumulation in cell filopodia, which suggests its involvement in ARMS cell migration. Furthermore, we observed that RasGRF1 becomes phosphorylated in ARMS after stimulation by several pro-metastatic factors, such as SDF-1 and HGF/SF, as well as after exposure to growth-promoting Igf-2 and insulin. More importantly, activation of RasGRF1 expression correlated with activation of p42/44 MAPK and AKT. When the expression of RasGRF1 was down-regulated in ARMS cells by an shRNA strategy, these RasGRF1-kd RMS cells did not respond to stimulation by SDF-1, HGF/SF, Igf-2 or insulin by phosphorylation of p42/44 MAPK and AKT and lost their chemotactic responsiveness; however, their adhesion was not affected. We also observed that RasGRF1-kd ARMS cells proliferated at a very low rate in vitro, and, more importantly, after inoculation into immunodeficient SCID/beige inbred mice they formed significantly smaller tumors. We conclude that RasGRF1 plays an important role in ARMS pathogenesis and is a new potential therapeutic target to inhibit ARMS growth.

Myogenic tumors in children and adolescents

Neoplasms of striated and smooth muscle in children are a diverse group of neoplasms that have some unique aspects in contrast to these tumors in adults. Rhabdomyosarcoma is the most common soft tissue sarcoma of infancy and childhood and is relatively common in adolescents. In contrast, smooth muscle tumors are relatively rare, and the various types of rhabdomyoma and smooth and skeletal muscle hamartomas are very uncommon. In recent years, the understanding of the pathologic and genetic aspects of rhabdomyosarcoma has been enhanced by adjunct techniques, such as immunohistochemistry and cytogenetic or molecular genetic analysis. The current classification of rhabdomyosarcoma emphasizes the histologic-prognostic correlations. This article reviews the clinicopathologic features of striated and smooth muscle tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents and the differential diagnosis.

Prevalence and clinical features of Costello syndrome and cardio-facio-cutaneous syndrome in Japan: findings from a nationwide epidemiological survey

Costello syndrome and cardio-facio-cutaneous (CFC) syndrome are congenital anomaly syndromes characterized by a distinctive facial appearance, heart defects, and intellectual disability. Germline mutations in HRAS cause Costello syndrome, and mutations in KRAS, BRAF, and MAP2K1/2 (MEK1/2) cause CFC syndrome. Since the discovery of the causative genes, approximately 150 new patients with each syndrome have been reported. However, the clinico-epidemiological features of these disorders remain to be identified. In order to assess the prevalence, natural history, prognosis, and tumor incidence associated with these diseases, we conducted a nationwide prevalence study of patients with Costello and CFC syndromes in Japan. Based on the result of our survey, we estimated a total number of patients with either Costello syndrome or CFC syndrome in Japan of 99 (95% confidence interval, 77-120) and 157 (95% confidence interval, 86-229), respectively. The prevalences of Costello and CFC syndromes are estimated to be 1 in 1,290,000 and 1 in 810,000 individuals, respectively. An evaluation of 15 adult patients 18-32 years of age revealed that 12 had moderate to severe intellectual disability and most live at home without constant medical care. These results suggested that the number of adult patients is likely underestimated and our results represent a minimum prevalence. This is the first epidemiological study of Costello syndrome and CFC syndrome. Identifying patients older than 32 years of age and following up on the patients reported here is important to estimate the precise prevalence and the natural history of these disorders.

Non-hodgkin lymphoma in a patient with cardiofaciocutaneous syndrome

Cardiofaciocutaneous (CFC) syndrome is a multiple congenital anomaly/mental retardation syndrome characterized by a distinctive facial appearance, ectodermal abnormalities, and heart defects. Clinically, it overlaps with both Noonan syndrome and Costello syndrome. Mutations in KRAS, BRAF, and MAP2K1/2 (MEK1/2) have been identified in patients with CFC syndrome. BRAF mutations are involved in more than 80% of CFC syndrome patients, and we have reported earlier that 2 CFC patients with BRAF mutations developed acute lymphoblastic leukemia. Here we report a boy with CFC syndrome who developed non-Hodgkin lymphoma. At 2 months of age, he developed pneumonia with pleurisy and was diagnosed as having non-Hodgkin lymphoma (precursor T-cell lymphoblastic lymphoma) by cytopathologic examination of the pleural fluid. He was suspected of having Noonan syndrome because of his facial appearance, webbed neck, and cubitus valgus. Precursor T-cell lymphoblastic lymphoma was treated by the TCCSG NHL 94-04 protocol. At 9 years of age, he was clinically reevaluated and diagnosed as having CFC syndrome because of his distinctive facial appearance, multiple nevi, and moderate mental retardation. Sequencing analysis showed a germline p.A246P (c.736G>C) mutation in BRAF reported earlier in CFC syndrome. Molecular diagnosis and careful observation should be considered in children with CFC syndrome.

Polyps and masses of the pediatric urinary bladder: a 21-year pathology review

Although not uncommon in adults, bladder tumors are rare in children. In addition, the histologic types of tumors seen in the pediatric population differ from those seen in adults. Although rhabdomyosarcoma is the most common pediatric bladder tumor, many other benign, malignant, and reactive lesions can be encountered. All may present clinically as a mass or polyp in the bladder. This study was designed to describe the pathology and patient demographics of pediatric bladder masses, because there are few studies describing these entities. Retrospectively reviewing our experience over a 21-year period, we identified 98 specimens from 65 patients with polyps or masses in the urinary bladder. As expected, the most frequent diagnosis was rhabdomyosarcoma. This was followed by fibroepithelial polyp and a variety of additional nonurothelial tumors. Only 7 urothelial tumors were identified, including 1 low-grade papillary urothelial carcinoma. Inflammatory lesions, such as cystitis cystica and nephrogenic adenoma, were invariably associated with an irritating factor when a history was provided. Our findings emphasize that diagnoses made in the pediatric urinary bladder are distinct from those in adults, although a wide variety of lesions may still be seen.

Cancer in Noonan, Costello, cardiofaciocutaneous and LEOPARD syndromes

Noonan syndrome (NS), Costello syndrome (CS), cardiofaciocutaneous syndrome (CFCS), and LEOPARD syndrome (now also referred to as Noonan syndrome with multiple lentigines or NSML) are clinically overlapping dominant disorders that are caused by mutations in RAS signaling pathway genes. The spectrum of cancer susceptibility in this group of disorders has not been studied in detail. We identified more than 1900 cases of NS, CS, CFCS, or NSML reported in the literature between 1937 and 2010; 88 cancers were reported. The most common cancers reported in 1051 NS subjects were neuroblastoma (n = 8), acute lymphoblastic leukemia (n = 8), low grade glioma (n = 6), and rhabdomyosarcoma (n = 6). These associations are biologically plausible, given that somatic RAS pathway mutations are known to occur in these specific cancers. In addition, 40 childhood cases of myeloproliferative disease were described in individuals with NS, several of whom experienced a benign course of this hematologic condition. We confirmed the previously described association between CS and cancer in 268 reported individuals: 19 had rhabdomyosarcoma, 4 had bladder cancer, and 5 had neuroblastoma. By age 20, the cumulative incidence of cancer was approximately 4% for NS and 15% for CS; both syndromes had a cancer incidence peak in childhood. The cancers described in CFCS and NSML overlapped with those reported in NS and CS. Future epidemiologic studies will be required to confirm the described cancer spectrum and to estimate precise cancer risks.

Cancer in Noonan, Costello, cardiofaciocutaneous and LEOPARD syndromes

Noonan syndrome (NS), Costello syndrome (CS), cardiofaciocutaneous syndrome (CFCS), and LEOPARD syndrome (now also referred to as Noonan syndrome with multiple lentigines or NSML) are clinically overlapping dominant disorders that are caused by mutations in RAS signaling pathway genes. The spectrum of cancer susceptibility in this group of disorders has not been studied in detail. We identified more than 1900 cases of NS, CS, CFCS, or NSML reported in the literature between 1937 and 2010; 88 cancers were reported. The most common cancers reported in 1051 NS subjects were neuroblastoma (n = 8), acute lymphoblastic leukemia (n = 8), low grade glioma (n = 6), and rhabdomyosarcoma (n = 6). These associations are biologically plausible, given that somatic RAS pathway mutations are known to occur in these specific cancers. In addition, 40 childhood cases of myeloproliferative disease were described in individuals with NS, several of whom experienced a benign course of this hematologic condition. We confirmed the previously described association between CS and cancer in 268 reported individuals: 19 had rhabdomyosarcoma, 4 had bladder cancer, and 5 had neuroblastoma. By age 20, the cumulative incidence of cancer was approximately 4% for NS and 15% for CS; both syndromes had a cancer incidence peak in childhood. The cancers described in CFCS and NSML overlapped with those reported in NS and CS. Future epidemiologic studies will be required to confirm the described cancer spectrum and to estimate precise cancer risks.

Clinical, pathological, and molecular analyses of cardiovascular abnormalities in Costello syndrome: a Ras/MAPK pathway syndrome

Cardiovascular abnormalities are important features of Costello syndrome and other Ras/MAPK pathway syndromes ("RASopathies"). We conducted clinical, pathological and molecular analyses of 146 patients with an HRAS mutation including 61 enrolled in an ongoing longitudinal study and 85 from the literature. In our study, the most common (84%) HRAS mutation was p.G12S. A congenital heart defect (CHD) was present in 27 of 61 patients (44%), usually non-progressive valvar pulmonary stenosis. Hypertrophic cardiomyopathy (HCM), typically subaortic septal hypertrophy, was noted in 37 (61%), and 5 also had a CHD (14% of those with HCM). HCM was chronic or progressive in 14 (37%), stabilized in 10 (27%), and resolved in 5 (15%) patients with HCM; follow-up data was not available in 8 (22%). Atrial tachycardia occurred in 29 (48%). Valvar pulmonary stenosis rarely progressed and atrial septal defect was uncommon. Among those with HCM, the likelihood of progressing or remaining stable was similar (37%, 41% respectively). The observation of myocardial fiber disarray in 7 of 10 (70%) genotyped specimens with Costello syndrome is consistent with sarcomeric dysfunction. Multifocal atrial tachycardia may be distinctive for Costello syndrome. Potentially serious atrial tachycardia may present in the fetus, and may continue or worsen in about one-fourth of those with arrhythmia, but is generally self-limited in the remaining three-fourths of patients. Physicians should be aware of the potential for rapid development of severe HCM in infants with Costello syndrome, and the need for cardiovascular surveillance into adulthood as the natural history continues to be delineated.