Neurofibromatosis type I and malignancy: review of 32 pediatric cases treated at a single institution

Genomic Newborn Screening for Pediatric Cancer Predisposition Syndromes: A Holistic Approach

As next-generation sequencing (NGS) has become more widely used, germline and rare genetic variations responsible for inherited illnesses, including cancer predisposition syndromes (CPSs) that account for up to 10% of childhood malignancies, have been found. The CPSs are a group of germline genetic disorders that have been identified as risk factors for pediatric cancer development. Excluding a few "classic" CPSs, there is no agreement regarding when and how to conduct germline genetic diagnostic studies in children with cancer due to the constant evolution of knowledge in NGS technologies. Various clinical screening tools have been suggested to aid in the identification of individuals who are at greater risk, using diverse strategies and with varied outcomes. We present here an overview of the primary clinical and molecular characteristics of various CPSs and summarize the existing clinical genomics data on the prevalence of CPSs in pediatric cancer patients. Additionally, we discuss several ethical issues, challenges, limitations, cost-effectiveness, and integration of genomic newborn screening for CPSs into a healthcare system. Furthermore, we assess the effectiveness of commonly utilized decision-support tools in identifying patients who may benefit from genetic counseling and/or direct genetic testing. This investigation highlights a tailored and systematic approach utilizing medical newborn screening tools such as the genome sequencing of high-risk newborns for CPSs, which could be a practical and cost-effective strategy in pediatric cancer care.

Conjunctival Marginal Zone Lymphoma in a Patient With Neurofibromatosis Type 1: A Case Report

We present a case of painless bulbar conjunctival mass due to B-cell non-Hodgkin lymphoma (NHL), without systemic involvement, in a 76-year-old man. Following an excision biopsy, histopathologic examination and immunohistochemistry confirmed the diagnosis, prompting a referral for hemato-oncological assessment. The patient underwent comprehensive laboratory and imaging scans, subsequently receiving combined chemo-immunotherapy that resulted in complete remission to date. This case is reported as it is crucial to recognize that a conjunctival insult might emerge in neurofibromatosis type 1 (NF1) patients.

Etiology of Acute Leukemia: A Review

Simple Summary

Acute leukemias are some of the most common cancers affecting all age groups. Despite a significant improvement made in the treatment of acute leukemias, their cause remains unknown. A number of genetic and environmental factors for the development of acute leukemias have been proposed, but none have been proven. Undoubtedly, genetics have a major role in the development of these diseases. The effects of a variety of environmental factors, occupations and hobbies have been explored. A recent “two-hit” theory” for the development of acute lymphoblastic leukemia has been proposed. This combines genetic factors and exposure to infections for the development of this disease. Several genetic factors are suggested. Most recently, for the infection portion, exposure to a virus containing Aspergillus Flavus has been proposed. This review summarizes what is currently known about the factors that are proposed for the development of acute leukemias.

Abstract

Acute leukemias constitute some of the most common malignant disorders. Despite significant progress made in the treatment of these disorders, their etiology remains unknown. A large and diverse group of genetic and environmental variables have been proposed. The role of a variety of factors, including pre-existing and acquired genetic mutations, exposure to radiation and various chemicals during preconception, pregnancy and throughout life, have been explored. The effects of inherited genetic variations and disorders, pre-existing diseases, infectious agents, hobbies, occupations, prior treatments, and a host of other factors have been proposed, but none is universally applicable to all cases. Variation in the incidence and prognosis based on the age, sex, race, type of the disease, geographic area of residence and other factors are intriguing but remain unexplained. Advances in genomic profiling, including genome-wide gene expression, DNA copy number and single nucleotide polymorphism (SNP) genotype, may shed some light on the role of genetics in these disparities. Separate two-hit hypotheses for the development of acute myeloblastic and lymphoblastic leukemia have been proposed. The latter combines genetics and infection factors resulting in leukemogenesis. A number of pre- and post-natal environmental conditions and exposure to infections, including a mycovirus infected Aspergillus flavus, have been suggested. The exact nature, timing, sequence of the events and mechanisms resulting in the occurrence of leukemia requires further investigations. This review summarizes some of the above factors in acute lymphoblastic and myeloblastic leukemias and the direction for future research on the etiology of these disorders.

Coincidental Expression of Classic Hodgkin Lymphoma and Neurofibromatosis Type I and Literature Review

Neurofibromatosis Type 1 (NF1) is a genetic disorder with an incidence of 1 in 2600 to 3000 individuals. It is a clinical diagnosis characterized by café-au-lait macules, neurofibromas, and axillary and/or groin freckling. Because of genetic mutations in the NF1 gene affecting the Ras/mitogen-activated protein kinase pathway, there is also risk of associated soft tissue sarcomas and hematologic malignancies. However, reports of classic Hodgkin lymphoma in patients with NF1 are sparse. We report an adolescent with NF1 who developed classic Hodgkin lymphoma. Although there is an unclear association between mutations in the NF1 gene and classic Hodgkin lymphoma, further studies are warranted.

Epithelioid sarcoma associated with neurofibromatosis type I

In general, patients with neurofibromatosis type I have a higher risk than those with other types of neurofibromatosis of developing soft-tissue sarcomas related to the nervous system. We here present a 42-year-old man with neurofibromatosis type I who developed a protruding mass over only 2 weeks. The histopathological diagnosis was epithelioid sarcoma. Epithelioid sarcomas are rare and, to the best of our knowledge, no epithelioid sarcomas have been reported in patients with neurofibromatosis type I. Radical excision of the primary lesion was performed and postoperative radiotherapy and chemotherapy administered, as is recommended for epithelioid sarcoma. Our case emphasizes that patients with neurofibromatosis type I may develop malignant tumors

Pediatric Adenocarcinoma in Korea: A Multicenter Study

Purpose

Adenocarcinoma is an extremely rare malignancy in the pediatric population. Research regarding pediatric adenocarcinoma is very rare in Korea. This study aimed to investigate the clinical features of pediatric adenocarcinomas of various primary organ sites in Korea.

Materials and Methods

Pediatric patients under 18 years, diagnosed with adenocarcinoma of various sites between January 1995 and December 2016, were included. We retrospectively reviewed patient and tumor characteristics and calculated survival estimates, reported as 5-year survival rate and 95% confidence interval.

Results

Of 80 patients (median age, 15 years; range, 10 to 17 years), 37 (46.3%) were men, and 24 (30%) had a family history of cancer or underlying disease relevant to malignancy. The cancer locations were the colon and rectum (n=32), ovaries (n=18), stomach (n=15), lung (n=4), small bowel (n=1), and other sites (n=10). Totally, 54.8% patients (42/77) had stage 3 or 4 disease. The median follow-up period was 2.0 years (range, 0 to 20.4). The 5-year overall survival estimate for all patients, and for those with stomach, colorectal, ovarian, and other cancer sites were 57.9%±11.5%, 58.2%±25.7%, 41.5%±18.2%, 87.5%±16.2%, and 64.0%±34.4%, respectively. The 5-year survival rate differed significantly between categories of adenocarcinomas into gastrointestinal (GI) (44.7%) and non-GI adenocarcinomas (78.8%) (p=0.007). The 5-year survival rate also differed significantly according to carcinoembryonic antigen level (69.3% in < 3 ng/mL, 23.8% in > 3 ng/mL; p < 0.001).

Conclusion

In pediatric patients, adenocarcinomas arise from various organs and are often diagnosed at advanced stages. Large, prospective studies for their accurate clinical characteristics and prognostic factors are needed.

Synchronous multiple colonic adenocarcinomas arising in patient with neurofibromatosis type 1

We report a case of synchronous multiple colon adenocarcinomas in a patient with neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant inherited disorder and patients with NF1 have high risk for both benign and malignant tumors. However, adenocarcinomas involving the colon have rarely been reported in patients with NF1. A 61-year-old man was referred for generalized peritonitis due to descending colon perforation. Left hemicolectomy was performed and pathologic examination showed four adenocarcinomas. Peritoneal nodules were confirmed as metastatic adenocarcinoma (pT4N1M1). The patient also had clinical features compatible with NF1 such as café au lait macules, axillary freckles, neurofibromas across the body, and Lisch nodules. Upon review of the literature, colon adenocarcinoma in patients with NF1 tends to occur in males and relatively young age groups, and is associated with advanced tumor stages and multiple colon cancers. To improve treatment outcome, early colonoscopic surveillance should be considered in patients with NF1.

Colonic adenocarcinoma as a secondary malignancy after treatment of embryonal rhabdomyosarcoma

BACKGROUND

Survivors of childhood malignancies are known to be at an increased risk for developing a variety of secondary cancers. Primary adenocarcinoma of the colon is very rare in children and adenocarcinoma of the colon occurring as a secondary malignancy in children is much rarer.

METHODS

A boy with a history of successfully treated embryonal rhabdomyosarcoma developed adenocarcinoma of the colon as a secondary cancer.

RESULTS

The boy presented with a solid mass of the left cheek at 3 years of age. The mass was excised and histological examination showed embryonal rhabdomyosarcoma. He was treated with multi-agent chemotherapy and local radiotherapy, which resulted in complete remission. Four years later, he presented with recurrent colicky abdominal pain and bleeding per rectum and was found to have intussusceptions. Colonoscopy revealed a tumor in the transverse colon, which was biopsied and proved to be an adenocarcinoma. The boy underwent excision followed by chemotherapy using an adult colon cancer regimen. He is currently off chemotherapy for 2 years with no evidence of the disease.

CONCLUSIONS

We report a rare case of colon cancer after treatment of rhabdomyosarcoma. Colorectal adenocarcinoma must be kept in mind as a secondary neoplasm following treatment for early childhood malignancies although it is extremely rare.

Survival meta-analyses for >1800 malignant peripheral nerve sheath tumor patients with and without neurofibromatosis type 1

There are conflicting reports as to whether malignant peripheral nerve sheath tumor (MPNST) patients with neurofibromatosis type 1 (NF1) have worse prognosis than non-NF1 MPNST patients. Large clinical studies to address this problem are lacking due to the rareness of MPNST. We have performed meta-analyses testing the effect of NF1 status on MPNST survival based on publications from the last 50 years, including only nonoverlapping patients reported from each institution. In addition, we analyzed survival characteristics for 179 MPNST patients from 3 European sarcoma centers. The meta-analyses including data from a total of 48 studies and >1800 patients revealed a significantly higher odds ratio for overall survival (OR(OS)) and disease-specific survival (OR(DSS)) in the non-NF1 group (OR(OS) = 1.75, 95% confidence interval [CI] = 1.28-2.39, and OR(DSS) = 1.68, 95% CI = 1.18-2.40). However, in studies published in the last decade, survival in the 2 patient groups has been converging, as especially the NF1 group has shown improved prognosis. For our own MPNST patients, NF1 status had no effect on overall or disease-specific survival. The compiled literature from 1963 to the present indicates a significantly worse outcome of MPNST in patients with NF1 syndrome compared with non-NF1 patients. However, survival for the NF1 patients has improved in the last decade, and the survival difference is diminishing. These observations support the hypothesis that MPNSTs arising in NF1 and non-NF1 patients are not different per se. Consequently, we suggest that the choice of treatment for MPNST should be independent of NF1 status.

Neoplasms associated with germline and somatic NF1 gene mutations

INTRODUCTION

Neurofibromatosis 1 is a tumor predisposition genetic syndrome with autosomal dominant inheritance and virtually 100% penetrance by the age of 5 years. NF1 results from a loss-of-function mutation in the NF1 gene, resulting in decreased levels of neurofibromin in the cell. Neurofibromin is a negative regulator of various intracellular signaling pathways involved in the cellular proliferation. Although the loss of heterozygosity in the NF1 gene may predispose NF1 patients to certain malignancies, additional genetic alterations are a prerequisite for their development. The precise nature of these additional genetic alterations is not well defined, and genetic testing of all malignancies in NF1 patients becomes an essential component of future research in this subset of patients. In addition to germline NF1 mutations, alteration of the somatic NF1 gene is associated with sporadic malignancies such as adenocarcinoma of the colon, myelodysplastic syndrome, and anaplastic astrocytoma.

MATERIALS AND METHODS

A comprehensive English and non-English language search for all articles pertinent to malignancies associated with NF1 was conducted using PubMed, a search engine provided by the U.S. National Library of Medicine and the National Institutes of Health. Key words searched included the following: "malignancies associated with NF1", "tumors associated with NF1", and "NF1 and malignancies". A comprehensive analysis in terms age and mode of presentation, investigation and therapeutic modalities, and outcome of the published data was performed and compared with similar information on the sporadic cases.

RESULTS

Malignancies in NF1 patients typically occur at an earlier age and, with an exception of optic pathway gliomas, certain types of malignancies carry a poor prognosis compared with their sporadic counterparts. Malignancies are the leading cause of death in NF1 patients, resulting in a 10- to 15-year decreased life expectancy compared with the general population.

CONCLUSIONS

The lack of well-defined screening tests for early detection and the nonspecific clinical presentation contributes to a poorer outcome in malignancies associated with NF1. Small study group size, mixed patient population, and a lack of uniformity in reporting research results make comparison of treatment outcome for this group difficult. An International Consensus Meeting to address and recommend best practices for screening, diagnosis, management, and follow-up of malignancies associated with NF1 is needed.

Soft tissue sarcomas and central nervous system tumors in children with neurofibromatosis type 1

OBJECTS

We aim to evaluate the characteristics of pediatric patients with neurofibromatosis type 1 (NF1) who developed soft tissue sarcomas (STSs) and central nervous system (CNS) tumors that have been followed up in our center.

MATERIALS AND METHODS

Medical records of children with NF1 were retrospectively analyzed.

RESULTS

There were 78 patients who met at least two diagnostic criteria for NF1. The median age of patients was 10 years (0.5-18), and M/F ratio was 1.3. The prevalance of the optic glioma was 11.5% (n = 9), and one patient with optic glioma also had cystic astrocytoma, one patient had brain stem tumor, and one patient had a CNS tumor (without histopathologic diagnosis). Seven of nine children were ≥ 7 years old at the time of the diagnosis of optic glioma. Visual impairment developed in four patients, and two of them were treated with radiotherapy solely on the basis of evidence of clinical and radiological progression of the tumors. Four patients developed STSs. Two of them had malignant peripheral nerve sheath tumors (MPNST), and the remaining two had bladder rhabdomyosarcoma. Three of the four patients with STSs died with progressive disease.

CONCLUSION

The clinical course of malignancy in NF1 is often different from that of similar tumor types in the general population. Careful follow-up in patients with NF1 is required to enable the early diagnosis of malignancies, and the developments of new targeted therapies are needed for improvement of the outcome for patients of this group, especially with MPNST.

Malignant brachial plexopathy: A pictorial essay of MRI findings

For imaging, the brachial plexus is a technically and anatomically challenging region of the peripheral nervous system. MRI has a central role in the identification and accurate characterization of malignant lesions arising here, as also in defining their extent and the status of the adjacent structures. The purpose of this pictorial essay is to describe the MRI features of primary and secondary malignant brachial plexopathies and radiation-induced brachial nerve damage.

An unusual self-limited clonal Mott cell proliferation with lymphoplasmacytic lymphoma-like features in a child with the Wiskott-Aldrich syndrome and Von Recklinghausen's neurofibromatosis

Patients with the Wiskott-Aldrich syndrome are at high risk for development of lymphomas, which are predominantly extranodal and of the immunoblastic type. We present a case of a self-limited lymphoproliferation with features of lymphoplasmacytic lymphoma arising in a patient with the Wiskott-Aldrich syndrome. The patient also had stigmata of von Recklinghausen's neurofibromatosis. The tumor was composed of CD138+, IgGkappa+, CD20-, PAX-5- Mott cells and CD5-, CD10-, CD19+, CD20+, CD43- small lymphoid B-cells that partially expressed CD23. The lymphadenopathy spontaneously resolved after a period of less than a year, and the patient had remained free of detectable lymphoproliferation for almost 4 years. He then developed Burkitt's lymphoma of the left parapharyngeal space. It is remarkable that both known lymphoproliferations with features of lymphoplasmatic lymphoma arising in patients with the Wiskott-Aldrich syndrome, this one and the previously described one, have spontaneously resolved. This observation is truly intriguing and requires further clinico-pathologic studies.

The Neurofibromatosis type 1:A dominantly inherited tumors-predisposing disorder

Neurofibromatosis type I (NF1) is a hereditary multisystem disease involving the skin and nervous system. It is the most common form of autosomal dominant phakomatoses with 100% penetrance but wide phenotypic variability. The NF1 gene is located on chromosome 17q11.2 and encodes for a tumour suppressor protein. Because affected individuals have an increased risk of tumor formation, this disorder is classified as inherited cancer syndrome. The risk of malignancies in NF1 affected patients is estimated to be 5–15% higher than in the general population. We reviewed clinical aspects and genetic mechanisms of tumorigenesis in NF1 affected patients.

Compound heterozygosity for MSH6 mutations in a pediatric lymphoma patient

An 8-year-old male with lymphoblastic lymphoma was noted to have multiple café-au-lait macules and possible Lisch nodules. Work-up revealed the child as compound heterozygous for mutations in the DNA mismatch repair gene, MSH6. This case emphasizes many clinical issues regarding individuals with biallelic mismatch repair mutations, a rare and easily missed hereditary predisposition to childhood cancer. The issues include the need for high clinical suspicion based on skin examination findings and family history, the phenotypic similarity to neurofibromatosis type 1 with possibility of misdiagnosis, the high risk for subsequent malignances, and the need for further research of possible treatment resistance.

Assessment of benign tumor burden by whole-body MRI in patients with neurofibromatosis 1

People with neurofibromatosis 1 (NF1) have multiple benign neurofibromas and a 10% lifetime risk of developing malignant peripheral nerve sheath tumors (MPNSTs). Most MPNSTs develop from benign plexiform neurofibromas, so the burden of benign tumors may be a risk factor for developing MPNST. We studied 13 NF1 patients with MPNSTs and 26 age- and sex-matched controls (NF1 patients who did not have MPNSTs) with detailed clinical examinations and whole-body MRI to characterize their body burden of internal benign neurofibromas. Internal plexiform neurofibromas were identified in 22 (56%) of the 39 NF1 patients studied. All six of the NF1 patients with MPNSTs under 30 years of age had neurofibromas visualized on whole-body MRI, compared to only 3 of 11 matched NF1 controls under age 30 (p < 0.05). Both the median number of plexiform neurofibromas (p < 0.05) and the median neurofibroma volume (p < 0.01) on whole-body MRI were significantly greater among MPNST patients younger than 30 years of age than among controls. No significant differences in whole-body MRI findings were observed between NF1 patients with MPNSTs and controls who were 30 years of age or older. Whole-body MRI of NF1 patients allows assessment of the burden of internal neurofibromas, most of which are not apparent on physical examination. Whole-body imaging of young NF1 patients may allow those at highest risk for developing MPNST to be identified early in life. Close surveillance of these high-risk patients may permit earlier diagnosis and more effective treatment of MPNSTs that develop.

Neurofibromatose tipo 1 na infância: revisão dos aspectos clínicos

OBJETIVO: Realizar uma revisão da literatura sobre neurofibromatose tipo 1 (NF1) em crianças e adolescentes, enfatizando as manifestações clínicas. FONTES DE DADOS: Artigos publicados, indexados na base de dados Medline e publicados entre 1998 a 2007, buscados pelos seguintes termos: "neurofibromatosis type 1", "neurofibroma", "von Recklinghausen" e "optic pathway gliomas". SÍNTESE DOS DADOS: A NF1 é uma doença genética autossômica dominante, crônica e progressiva, com incidência de 1/2.000 a 1/7.800 nascidos vivos. Tem sido observada em diferentes partes do mundo, em todas as raças e nos dois sexos. Metade dos casos representa mutações novas. A taxa de mutação para o gene NF1 é de 1/10.000, a qual se deve ao fato do gene ser grande e possuir estrutura interna atípica, que predispõe a deleções e mutações. O diagnóstico presuntivo da NF1 é feito por critérios clínicos. As três principais manifestações - neurofibromas, manchas café-com-leite e nódulos de Lisch - ocorrem em mais de 90% dos pacientes até a puberdade. CONCLUSÕES: Os cuidados com os pacientes com NF1 devem antecipar as principais complicações e oferecer um tratamento precoce. No aconselhamento genético, é importante informar pais e familiares a respeito do panorama geral da doença e suas possíveis complicações, enfatizando que a maioria dos pacientes apresenta vida saudável e produtiva.

Colonic vascular anomalies and colon cancer in neurofibromatosis: report of a case

We report a case of neurofibromatosis with synchronous adenocarcinomas in the sigmoid and transverse colon. There was widespread intimal proliferation in arteries in the region of the tumors and also in the cecum. Such vascular lesions are associated with von Recklinghausen's disease. The cecal lesion produced mural thickening visible on computed tomography. This case supports a possible genetic link between neurofibromatosis and adenocarcinoma of the colon.

Management of childhood malignant peripheral nerve sheath tumor

Malignant peripheral nerve sheath tumor (MPNST) is rare, but is one of the most frequent non-rhabdomyosarcoma soft-tissue sarcomas in the pediatric population. These tumors occur most frequently at axial sites and are characterized by local aggressiveness and a propensity to metastasize. They are often associated with neurofibromatosis type 1 (NF-1): the lifetime risk of patients with NF-1 developing MPNST has been estimated at 8-13%, compared with 0.001% in the general population. Because of the rarity of this tumor, little information is available on its clinical management, particularly in the pediatric age group. In a recent report on the clinical findings and treatment outcomes from a large number of children and adolescents with MPNST in an Italian and German series, less satisfactory overall outcomes than those for other pediatric sarcomas were described. Therefore, the approach to the treatment of patients with MPNST should be aggressive and risk adapted, and is necessarily complex. Patients should be referred to selected institutions with adequate experience in treating soft-tissue sarcomas, and with the multidisciplinary skills for enrolling patients in clinical trials. Surgical resection represents the mainstay of treatment, while the role of adjuvant treatment is not yet clear. Post-operative radiotherapy seems to have a role in improving local control, although the potential morbidity of irradiation should be taken into account, particularly when treating children. Although lack of local control is the major cause of treatment failure, MPNST may give rise to distant metastases. These tumors are usually considered as having uncertain chemosensitivity, but recent evidence suggests that there may be a role for chemotherapy in patients with a high-grade histology. For the near future, our hopes lie in the development of novel tailored therapies directed specifically against the molecular targets of the neoplastic cells: soft-tissue sarcomas seem particularly promising candidates for targeted therapy.

Soft-tissue sarcomas in children and adolescents with neurofibromatosis type 1

BACKGROUND

Patients affected by neurofibromatosis type 1 (NF1) are at higher risk of developing soft-tissue sarcomas (STS) than the general population. The clinical findings and outcome in 43 children and adolescents with NF1 treated for STS in the Italian protocols between 1988 and 2004 are reported.

METHODS

The study included 37 patients with neurogenic sarcomas (36 malignant peripheral nerve sheath tumors [MPNST], 1 triton tumor) and 6 cases of rhabdomyosarcoma (RMS). The prevalence of NF1 observed during the study period was 43% in the MPNST population and 1% in the RMS group.

RESULTS

Most patients with neurogenic sarcomas had large, invasive tumors. Five-year event-free and overall survival rates were 19% and 28%, respectively. Two of 16 patients with evaluable disease responded to chemotherapy. All 6 RMS patients were </=3 years old and had embryonal subtype, 5 of 6 arising in the genitourinary tract or pelvis (paravesical); 4 were alive in first remission at the time of the analysis, 1 was alive in second remission after a local recurrence, and 1 died of disease.

CONCLUSIONS

The occurrence of STS in pediatric patients with NF1 syndrome in Italy is discussed, confirming that NF1 patients have a high risk of developing STS, and particularly MPNST, often with an aggressive clinical presentation and poor outcome. Cases of RMS tended to have particular features (early age, embryonal histotype, genitourinary site) and their outcome seemed to resemble that of the general RMS population.

Endoscopic excision of a supraorbital schwannoma

Patients with neurofibromatosis 1 frequently require multiple tumor excisions over the course of many years. Minimally invasive techniques of excision offer promise in reducing morbidity and scarring in a group of patients with well-circumscribed benign tumors in aesthetically sensitive areas. The safety and efficacy of endoscopic approaches to a variety of conditions affecting the craniofacial frontal region are well established. This report describes the endoscopic excision of a benign supraorbital nerve schwannoma in a 5-year-old girl.

Risk factors for acute leukemia in children: a review

Although overall incidence is rare, leukemia is the most common type of childhood cancer. It accounts for 30% of all cancers diagnosed in children younger than 15 years. Within this population, acute lymphocytic leukemia (ALL) occurs approximately five times more frequently than acute myelogenous leukemia (AML) and accounts for approximately 78% of all childhood leukemia diagnoses. Epidemiologic studies of acute leukemias in children have examined possible risk factors, including genetic, infectious, and environmental, in an attempt to determine etiology. Only one environmental risk factor (ionizing radiation) has been significantly linked to ALL or AML. Most environmental risk factors have been found to be weakly and inconsistently associated with either form of acute childhood leukemia. Our review focuses on the demographics of childhood leukemia and the risk factors that have been associated with the development of childhood ALL or AML. The environmental risk factors discussed include ionizing radiation, non-ionizing radiation, hydrocarbons, pesticides, alcohol use, cigarette smoking, and illicit drug use. Knowledge of these particular risk factors can be used to support measures to reduce potentially harmful exposures and decrease the risk of disease. We also review genetic and infectious risk factors and other variables, including maternal reproductive history and birth characteristics.

Survival data for patients with malignant schwannoma

Malignant schwannomas are uncommon sarcomas that arise from the sheath of Schwann surrounding peripheral nerve fibers. These tumors may arise spontaneously in adult patients or may occur with reportedly increased frequency in patients with neurofibromatosis Type I. The tumors have had a reputation for malignancy with rapid metastasis, especially when they arise in relation to neurofibromatosis. We have reviewed the experience of the connective tissue oncology unit with patients with these tumors during the past 25 years. There were 80 malignant schwannomas identified in 41 females and 39 males with a mean age of 36 +/- 17 years. The largest numbers of tumors were seen in the thigh, shoulder, and pelvis but they also occurred in more central (abdomen and thorax) and distal (forearm, hand and foot) locations. The Musculoskeletal Tumor Society stages showed that the majority of the patients had Stage II (high grade but not metastasized) tumors; however, additionally, 10 of the patients had metastases at outset (Stage III). Patient gender was not a factor but stage was a notable determinant of survival. Anatomic location also had a significant effect. Overall, the entire series of patients had a survival of 85% at 11 +/- 5 years and even more remarkable was the fact that there was no difference between the numbers and outcome statistics for tumors arising spontaneously and those occurring in patients with neurofibromatosis.

Second neoplasms in pediatric patients with primary central nervous system tumors

BACKGROUND

Details on second neoplasms (SNs) following pediatric central nervous system (CNS) tumors are scant, because of the rarity of such SNs. The goal of the current study was to investigate and characterize these rare SNs.

METHODS

The authors reviewed clinical and treatment data on all institutional patients age < 22 years at diagnosis of a primary CNS tumor who developed any type of SN. Patients with neurofibromatosis type 1 were excluded. Cumulative incidence rates were estimated, and putative risk factors were analyzed.

RESULTS

The SNs investigated in the current study included 10 gliomas (42%), 5 meningiomas (21%), 2 desmoid tumors, 2 myelodysplastic syndromes, 2 basal cell carcinomas, 1 leukemia, 1 malignant fibrous histiocytoma, and 1 thyroid carcinoma. Twenty-one patients had previously received radiotherapy, and 12 patients had received chemotherapy. The SN was related to a genetic cause in 7 patients (29%). Eleven patients died of their SNs, including 8 patients with glioma and 2 patients with myelodysplastic syndromes. The estimated 15-year cumulative incidence rate for malignant SNs was 4%. Children with choroid plexus tumors had an estimated 10-year cumulative incidence rate of 20.2%; 2 of those patients had germline TP53 mutations. Age </= 2 years was a significant risk factor (P = 0.016) for development of an SN only when patients with genetic conditions were included in the analysis. No significant difference in the estimated cumulative incidence of SNs was found among patients who had received different types of therapy.

CONCLUSIONS

The risk of lethal SNs after pediatric CNS tumors is small. Young patients and patients with choroid plexus tumors appear to have an increased risk of SNs that is associated with genetic factors.

Identification of growth hormone receptor in localised neurofibromas of patients with neurofibromatosis type 1

BACKGROUND

The hallmark of neurofibromatosis type 1 (NF1) is the development of multiple neurofibromas. Solitary neurofibroma may occur in an individual who does not have NF1, but multiple neurofibromas tend to develop only in those with NF1. It has been suggested that hormones may influence the neurofibromas of patients with NF1. The evidence that hormones may influence the growth of neurofibromas comes mainly from the observation that localised neurofibromas of patients with NF1 commonly grow during puberty and pregnancy. Because growth hormone (GH) concentrations increase during puberty, it is possible that GH influences the growth of these tumours.

AIMS

To investigate the presence of GH receptors (GHRs) in neurofibromas.

METHODS

By means of immunohistochemistry, the presence of GHRs was investigated in two groups of patients: 16 patients without NF1 with solitary neurofibromas (group A) and 10 patients with NF1 with localised neurofibromas (group B).

RESULTS

Six of the 16 patients in group A had neurofibromas that were immunopositive for GHR, whereas nine of the 10 patients in group B were immunopositive.

CONCLUSIONS

Most patients with NF1 have localised neurofibromas that express GHR. This suggests that GH may play some role in the development of localised neurofibromas in patients with NF1.

Neurofibromatosis 1: clinical manifestations and diagnostic criteria

Neurofibromatosis 1 occurs in 2 to 3 people per 10,000. The most frequent clinical features are café-au-lait macules, neurofibromas, intertriginous freckling, Lisch nodules, and learning disabilities, but optic and other gliomas, malignant peripheral nerve sheath tumors, and characteristic osseous lesions also can be present. Two striking aspects of neurofibromatosis 1 are its progressive nature and its extreme variability. This article reviews the natural history and some important clinical manifestations of neurofibromatosis 1, with emphasis on features that constitute the standard diagnostic criteria. The pathogenic implications of these clinical manifestations are also considered.

Neurofibromas in children with neurofibromatosis 1

Neurofibromatosis 1 is a common autosomal dominant disease reported in approximately 1 in 3000 individuals. Although some features of neurofibromatosis 1, such as café-au-lait spots and Lisch nodules, are clinically silent, neurofibromas cause a significant degree of morbidity, mortality, and cosmetic disfigurement. Childhood through early adulthood is a vulnerable period for the growth of these lesions. Neurofibromas are a heterogeneous group of benign tumors that grow from intraneural and extraneural tissues. These tumors take on different morphology, grow at variable rates, and occur in multiple locations. Symptoms arise as neurofibromas enlarge, compressing and distorting local structures. The unpredictable nature of neurofibromas has a serious impact on the quality of life of patients with neurofibromatosis 1, and their management is challenging for physicians. Surgical removal remains the mainstay of treatment. However, advances in the understanding of the genetics and pathogenesis of neurofibromatosis 1 have led to the development of promising new biologically directed therapies. The purpose of this review is to summarize the defining characteristics, incidence, clinical course, management options, and outcome of neurofibromas in children with neurofibromatosis 1.

Segmentally distributed neurofibromatosis associated with adenocarcinoma of the colon

Neurofibromatosis can be associated with various malignancies, but an association with adenocarcinoma is extremely rare. A 61-year-old man who had been diagnosed with adenocarcinoma of the hepatic flexure of the colon was referred for segmentally located, multiple café-au-lait spots and tumors on his back and axillary freckles for 40 years. Histopathologic examination of the tumor was consistent with the neurofibromatosis. We report an unusual case of type I neurofibromatosis associated with adenocarcinoma of the colon that was clinically similar to segmental neurofibromatosis.

Second malignancies in children: the usual suspects?

The aim of this article is to provide an up to date review of second malignant neoplasms (SMN's) following treatment for childhood cancer, referring to their incidence, the role of genetic factors, and how the primary malignancy and treatment received influence the type, site and prognosis of SMN's. The role of genetic factors will be discussed as far as they impact upon a predisposition to later development of SMN's. The primary malignancies that have important associations with SMN's will then be discussed, in particular Hodgkin's disease, retinoblastoma and acute lymphoblastic leukaemia. The important second malignancies will be highlighted, including tumours of the CNS and thyroid, osteosarcoma, secondary acute myeloid leukaemia and melanoma. Emphasis will be put upon identifying which patients are most likely to suffer from these tumours. An important part of the article are case histories. These are provided in combination with illustrations as a useful adjunct to the text, with a particular emphasis on radiological features, diagnosis and screening. Finally, the important but different roles of causal agents, in particular chemotherapy and radiotherapy are highlighted.

Malignancy in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) represents a major risk factor for development of malignancy, particularly malignant peripheral nerve sheath tumors (MPNST), optic gliomas, other gliomas, and leukemias. The oncologist will see NF1 patients referred for treatment of malignancy, and should be alert to the possibility of undiagnosed NF1 among patients with cancer. Brain tumors tend to have a more indolent course in NF1 than in the general population, and hence are best managed conservatively. MPNST, in contrast, do not respond to standard chemotherapy or radiation therapy. The most effective treatment of MPNST appears to be early diagnosis and surgery, but early diagnosis is hampered by frequent occurrence within preexisting large tumors, making new growth or change difficult to detect. New insights into pathogenesis now offer hope of development of specific methods of treatment with reduced toxicity and more precise molecular targeting. There is an urgent need, however, to develop methods to measure tumor growth and monitor outcomes, develop preclinical drug screening systems, and further explore the pathogenesis of the disorder to determine whether mechanisms other than Ras regulation may be important in pathogenesis.

Second malignancies in children: the usual suspects?

The aim of this article is to provide an up to date review of second malignant neoplasms (SMN's) following treatment for childhood cancer, referring to their incidence, the role of genetic factors, and how the primary malignancy and treatment received influence the type, site and prognosis of SMN's. The role of genetic factors will be discussed as far as they impact upon a predisposition to later development of SMN's. The primary malignancies that have important associations with SMN's will then be discussed, in particular Hodgkin's disease, retinoblastoma and acute lymphoblastic leukaemia. The important second malignancies will be highlighted, including tumours of the CNS and thyroid, osteosarcoma, secondary acute myeloid leukaemia and melanoma. Emphasis will be put upon identifying which patients are most likely to suffer from these tumours. An important part of the article are case histories. These are provided in combination with illustrations as a useful adjunct to the text, with a particular emphasis on radiological features, diagnosis and screening. Finally, the important but different roles of causal agents, in particular chemotherapy and radiotherapy are highlighted.

Neonatal brain tumors: a review

This article presents two cases of infants with brain tumors and reviews the literature pertinent to congenital and neonatal brain tumors. Information regarding epidemiology, presentation, prognosis, and clinical management are also addressed with specific regard to differences between neonatal and childhood brain tumors. An appeal is made to consider (1) coordination of the care of these children through pediatric multidisciplinary neuro-oncology programs; (2) enrollment, whenever possible, in clinical trials; and (3) submission of available tumor tissue to pediatric tumor banks to assure its availability to interested researchers.

Neurofibromatosis-Noonan syndrome and acute lymphoblastic leukemia: a report of two cases

Two boys with neurofibromatosis-Noonan syndrome in whom acute lymphoblastic leukemia (ALL) developed are described. Both patients demonstrated B-lineage leukemias with normal cytogenetics. They were treated with combination chemotherapy and remain in remission off therapy. Patients with neurofibromatosis-Noonan syndrome may be at increased risk for ALL.

MR imaging differentiation of benign and malignant peripheral nerve sheath tumors: use of the target sign

BACKGROUND

T2-weighted MR imaging of soft tissue tumors of neural origin may show round lesions with a central hypointensity and a hyperintense rim resembling a target. We define the "target sign" as a mass consisting of a solitary target, or a multicompartmental mass in which the largest component consists of multiple targets.

OBJECTIVE

The objective of this study was to determine whether the target sign can differentiate benign neurofibromas and their malignant counterparts, malignant peripheral nerve sheath tumors. Materials and methods. Preoperative T2-weighted MR images of 23 neurofibromas or malignant peripheral nerve sheath tumors were retrospectively reviewed in 16 patients, aged 3 weeks to 20 years (median 15 years), without knowledge of the pathologic diagnosis. The presence or absence of a target sign was noted.

RESULTS

The target sign was seen in all 12 neurofibromas and 1 of the 11 malignant peripheral nerve sheath tumors. Statistical analysis showed good differentiation of benign and malignant tumors using this sign (chi = 0.91).

CONCLUSION

The target sign on T2-weighted MR imaging is helpful in differentiating neurofibromas from malignant peripheral nerve sheath tumors.

Absence of germline mutations in exons 5-9 of the p53 gene in patients with Li-Fraumeni-like (SBLA) and familial adenomatous polyposis heritable cancer syndromes

Although acquired mutations in the human p53 gene occur in many tumor types, germline mutations are rare. An exception is the occurrence of germline p53 mutations in a fraction of families afflicted with the Li-Fraumeni syndrome (LFS). Previous studies from our laboratory demonstrated increased levels of wild type p53 protein in skin fibroblasts (SF) of patients from heritable cancer syndrome, including familial adenomatous polyposis (FAP), neurofibromatosis type 1 (NF1), and bilateral retinoblastoma (bRB) (Kopelovich and DeLeo, 1984,1986). Here, we further address the association between germline p53 alterations and genetic predisposition to cancer in the SBLA syndrome and in FAP. DNA sequencing and single-stranded conformational polymorphism analysis (SSCP) were utilized to screen for the presence of mutations within exons 5-9 of the p53 gene in SF and in benign tumors. Thus we observed no germline mutations in exons 5-9 of the p53 gene in SF from SBLA or FAP patients, including the Gardner variant. In addition, we observed no acquired mutations in exons 5-9 of the p53 gene in benign tumors from FAP patients. In conclusion, we found no association between germline p53 mutations and SBLA or FAP. How mechanisms that involve nonmutational activation of the p53 protein might affect genetic predisposition to cancer remains to be established.

Association of childhood rhabdomyosarcoma with neurofibromatosis type I and birth defects

Rhabdomyosarcoma (RMS) is an uncommon malignant soft tissue sarcoma whose cause is largely unknown. Reported risk factors include genetic alterations (e.g., p53 mutations, a defective gene at 11p15.5, or specific chromosomal translocation of t(2:13)), and parents' use of drugs around the time of conception. We present results from a national, case-control study of 249 RMS cases (170 males and 79 females) and 302 controls (196 males and 106 females). The cases, aged 0-20 years at diagnosis, were identified via the Intergroup RMS Study-III during 1982-1988. Controls were selected by random digit telephone dialing. As a supplement to the original study, information on genetic diseases and birth defects (BD) was collected from the subjects' parents by telephone interview. Fifty-six (22.5%) cases and 55 (18.2%) controls were reported to have genetic diseases or BD (odds ratio [OR] = 1.30,95% confidence interval [CI] = 0.85-2.02, P = .21). The case group had a significantly higher frequency of neurofibromatosis type I (NF1) than did the control group, i.e., five cases (2.0%) had NF1 vs. zero controls (P = .02). The case group also had a higher frequency of major BDs than did the control group (6.0% vs. 2.6%, OR = 2.36, 95% CI = 0.92-6.52, P = .05). However, this excess was only observed in males (7.6% vs. 2.6%, OR = 3.16, 95% CI = 1.02-10.41, P = .02). Among the 15 cases having both RMS and major BDs, six (40.0%) had both conditions in the same regional anatomic site: Two (13.3%) had both in the extremities, two (13.3%) in the genitourinary system, and two in the head and neck. These findings suggest that common genetic mechanisms or in utero exposures may be involved in the development of many childhood tumors and congenital abnormalities.