Recent advances in the developmental origin of neuroblastoma: an overview.

Neuroblastoma (NB) is a pediatric tumor that originates from neural crest-derived cells undergoing a defective differentiation due to genomic and epigenetic impairments. Therefore, NB may arise at any final site reached by migrating neural crest cells (NCCs) and their progeny, preferentially in the adrenal medulla or in the para-spinal ganglia.NB shows a remarkable genetic heterogeneity including several chromosome/gene alterations and deregulated expression of key oncogenes that drive tumor initiation and promote disease progression.NB substantially contributes to childhood cancer mortality, with a survival rate of only 40% for high-risk patients suffering chemo-resistant relapse. Hence, NB remains a challenge in pediatric oncology and the need of designing new therapies targeted to specific genetic/epigenetic alterations become imperative to improve the outcome of high-risk NB patients with refractory disease or chemo-resistant relapse.In this review, we give a broad overview of the latest advances that have unraveled the developmental origin of NB and its complex epigenetic landscape.Single-cell RNA sequencing with spatial transcriptomics and lineage tracing have identified the NCC progeny involved in normal development and in NB oncogenesis, revealing that adrenal NB cells transcriptionally resemble immature neuroblasts or their closest progenitors. The comparison of adrenal NB cells from patients classified into risk subgroups with normal sympatho-adrenal cells has highlighted that tumor phenotype severity correlates with neuroblast differentiation grade.Transcriptional profiling of NB tumors has identified two cell identities that represent divergent differentiation states, i.e. undifferentiated mesenchymal (MES) and committed adrenergic (ADRN), able to interconvert by epigenetic reprogramming and to confer intra-tumoral heterogeneity and high plasticity to NB.Chromatin immunoprecipitation sequencing has disclosed the existence of two super-enhancers and their associated transcription factor networks underlying MES and ADRN identities and controlling NB gene expression programs.The discovery of NB-specific regulatory circuitries driving oncogenic transformation and maintaining the malignant state opens new perspectives on the design of innovative therapies targeted to the genetic and epigenetic determinants of NB. Remodeling the disrupted regulatory networks from a dysregulated expression, which blocks differentiation and enhances proliferation, toward a controlled expression that prompts the most differentiated state may represent a promising therapeutic strategy for NB.

Single-cell transcriptomics of human embryos identifies multiple sympathoblast lineages with potential implications for neuroblastoma origin.

Characterization of the progression of cellular states during human embryogenesis can provide insights into the origin of pediatric diseases. We examined the transcriptional states of neural crest- and mesoderm-derived lineages differentiating into adrenal glands, kidneys, endothelium and hematopoietic tissue between post-conception weeks 6 and 14 of human development. Our results reveal transitions connecting the intermediate mesoderm and progenitors of organ primordia, the hematopoietic system and endothelial subtypes. Unexpectedly, by using a combination of single-cell transcriptomics and lineage tracing, we found that intra-adrenal sympathoblasts at that stage are directly derived from nerve-associated Schwann cell precursors, similarly to local chromaffin cells, whereas the majority of extra-adrenal sympathoblasts arise from the migratory neural crest. In humans, this process persists during several weeks of development within the large intra-adrenal ganglia-like structures, which may also serve as reservoirs of originating cells in neuroblastoma.

Neurocristopathies: Enigmatic Appearances of Neural Crest Cell-derived Abnormalities.

The neural crest is an important transient structure that develops during embryogenesis in vertebrates. Neural crest cells are multipotent progenitor cells that migrate and develop into a diverse range of cells and tissues throughout the body. Although neural crest cells originate from the ectoderm, they can differentiate into mesodermal-type or endodermal-type cells and tissues. Some of these tissues include the peripheral, autonomic, and enteric nervous systems; chromaffin cells of the adrenal medulla; smooth muscles of the intracranial blood vessels; melanocytes of the skin; cartilage and bones of the face; and parafollicular cells of the thyroid gland. Neurocristopathies are a group of diseases caused by the abnormal generation, migration, or differentiation of neural crest cells. They often involve multiple organ systems in a single person, are often familial, and can be associated with the development of neoplasms. As understanding of the neural crest has advanced, many seemingly disparate diseases, such Treacher Collins syndrome, 22q11.2 deletion syndrome, Hirschsprung disease, neuroblastoma, neurocutaneous melanocytosis, and neurofibromatosis, have come to be recognized as neurocristopathies. Neurocristopathies can be divided into three main categories: dysgenetic malformations, neoplasms, and combined dysgenetic and neoplastic syndromes. In this article, neural crest development, as well as several associated dysgenetic, neoplastic, and combined neurocristopathies, are reviewed. Neurocristopathies often have clinical manifestations in multiple organ systems, and radiologists are positioned to have significant roles in the initial diagnosis of these disorders, evaluation of subclinical associated lesions, creation of treatment plans, and patient follow-up. Online supplemental material is available for this article. ©RSNA, 2019.

Metastatic neuroblastoma diagnosed on prenatal sonographic examination performed for decreased fetal movement.

We report a case of fetal neuroblastoma presenting with massive liver metastasis diagnosed during the biophysical profile sonographic examination performed for decreased fetal movement. The patient presented at 37 weeks' gestation with limited fetal movement over 24 hours. Biophysical profile showed marked polyhydramnios and an enlarged abdomen filled with a homogeneous mass lesion suspicious for liver metastasis. Primary urgent cesarean section was performed revealing a cachectic neonate with a rigid and grossly distended abdomen. Neonatal evaluation confirmed the etiology of the abdominal mass to be liver metastasis from neuroblastoma. The child died on the 46th day. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:502-506, 2017.

Diagnostic Imaging of Fetal and Neonatal Abdominal and Soft Tissue Tumors.

Imaging plays a key role in the diagnosis and staging of prenatal and neonatal tumors, and is essential in treatment planning. Though obstetrical ultrasound is the first choice prenatally, fetal MRI continues to play an increasing role as experience with this imaging modality increases. In the neonate, in addition to ultrasound and MRI, CT and nuclear medicine studies can also play an important role. We describe the prenatal and neonatal imaging findings of some of the most common congenital abdominal and soft tissue neoplasms including neuroblastoma, renal, liver and soft tissue tumors.

Ascl1 phospho-status regulates neuronal differentiation in a Xenopus developmental model of neuroblastoma.

Neuroblastoma (NB), although rare, accounts for 15% of all paediatric cancer mortality. Unusual among cancers, NBs lack a consistent set of gene mutations and, excluding large-scale chromosomal rearrangements, the genome seems to be largely intact. Indeed, many interesting features of NB suggest that it has little in common with adult solid tumours but instead has characteristics of a developmental disorder. NB arises overwhelmingly in infants under 2 years of age during a specific window of development and, histologically, NB bears striking similarity to undifferentiated neuroblasts of the sympathetic nervous system, its likely cells of origin. Hence, NB could be considered a disease of development arising when neuroblasts of the sympathetic nervous system fail to undergo proper differentiation, but instead are maintained precociously as progenitors with the potential for acquiring further mutations eventually resulting in tumour formation. To explore this possibility, we require a robust and flexible developmental model to investigate the differentiation of NB's presumptive cell of origin. Here, we use Xenopus frog embryos to characterise the differentiation of anteroventral noradrenergic (AVNA) cells, cells derived from the neural crest. We find that these cells share many characteristics with their mammalian developmental counterparts, and also with NB cells. We find that the transcriptional regulator Ascl1 is expressed transiently in normal AVNA cell differentiation but its expression is aberrantly maintained in NB cells, where it is largely phosphorylated on multiple sites. We show that Ascl1's ability to induce differentiation of AVNA cells is inhibited by its multi-site phosphorylation at serine-proline motifs, whereas overexpression of cyclin-dependent kinases (CDKs) and MYCN inhibit wild-type Ascl1-driven AVNA differentiation, but not differentiation driven by a phospho-mutant form of Ascl1. This suggests that the maintenance of ASCL1 in its multiply phosphorylated state might prevent terminal differentiation in NB, which could offer new approaches for differentiation therapy in NB.

Cyclin D1 in human neuroblastic tumors recapitulates its developmental expression: An immunohistochemical study.

The protein cyclin D1 (CD1), which belongs to a family of proteins functioning as regulators of CDKs (cyclin-dependent kinases) throughout the cell cycle, has been immunohistochemically detected in a wide variety of human malignant tumors. The aim of the present study was to investigate immunohistochemically the expression and distribution of CD1 in the developing human peripheral sympathetic nervous system (PSNS) and in childhood peripheral neuroblastic tumors (neuroblastomas, ganglioneuroblastomas, and ganglioneuromas). The above mentioned fetal and neoplastic tissues represent an in vivo model in which undifferentiated neuroblastic cells undergo ganglion cell differentiation. During development, a strong nuclear expression of CD1 was restricted to neuroblasts, disappearing progressively from the maturing ganglion cells with increasing gestational age. In neoplastic tissues, CD1 immunoreactivity was restricted to neuroblastic cell component of all neuroblastomas and ganglioneuroblastomas, whereas it was absent or only focally detectable in maturing/mature ganglion cell component of differentiating neuroblastomas, ganglioneuroblastomas, and ganglioneuromas. We conclude that CD1 is a reliable marker, which can be used routinely to stain neuroblastic cells in both developing and neoplastic tissues. Furthermore, our results indicate that CD1 expression in childhood peripheral neuroblastic tumors recapitulates the changes during normal development of PSNS, as previously reported for Bcl-2 oncoprotein, c-ErbB2, insulin-like growth factor 2, ß-2-microglobulin, and cathepsin D. This is consistent with the current view that childhood peripheral neuroblastic tumors exhibit gene expression profiles mirroring those occurring during PSNS development.

Neuroblastoma: molecular pathogenesis and therapy.

Neuroblastoma is a developmental tumor of young children arising from the embryonic sympathoadrenal lineage of the neural crest. Neuroblastoma is the primary cause of death from pediatric cancer for children between the ages of one and five years and accounts for ∼13% of all pediatric cancer mortality. Its clinical impact and unique biology have made this aggressive malignancy the focus of a large concerted translational research effort. New insights into tumor biology are driving the development of new classification schemas. Novel targeted therapeutic approaches include small-molecule inhibitors as well as epigenetic, noncoding-RNA, and cell-based immunologic therapies. In this review, recent insights regarding the pathogenesis and biology of neuroblastoma are placed in context with the current understanding of tumor biology and tumor/host interactions. Systematic classification of patients coupled with therapeutic advances point to a future of improved clinical outcomes for this biologically distinct and highly aggressive pediatric malignancy.

Neuroblastoma in monozygotic twins with distinct presentation pathology and outcome: is it familial or in utero metastasis.

To date ten sets of monozygotic twins with neuroblastoma have been reported in the literature. Twin-to-twin in utero metastasis have been proposed as the mechanism of tumor development in the second twin; based on similar pathology, presence of metastatic disease, absence of a primary tumor, and/or later presentation in the second twin. Hereditary neuroblastoma has not been described in this context. We propose that primary neuroblastoma can occur in monozygotic twins without twin-twin transmission; due to the different ages of presentation, histology, ploidy, and tumor behavior.

Neuroblastoma cells injected into experimental mature teratoma reveal a tropism for embryonic loose mesenchyme.

Embryonic neural tumors are responsible for a disproportionate number of cancer deaths in children. Although dramatic improvements in survival for pediatric malignancy has been achieved in previous years advancements seem to be slowing down. For the development of new enhanced therapy and an increased understanding of the disease, pre-clinical models better capturing the neoplastic niche are essential. Tumors of early childhood present in this respect a particular challenge. Here, we explore how components of the embryonic process in stem­cell induced mature teratoma can function as an experimental in vivo microenvironment instigating the growth of injected childhood neuroblastoma (NB) cell lines. Three human NB cell lines, IMR-32, Kelly and SK-N-BE(2), were injected into mature pluripotent stem cell­induced teratoma (PSCT) and compared to xenografts of the same cell lines. Proliferative NB cells from all lines were readily detected in both models with a typical histology of a poorly differentiated NB tumor with a variable amount of fibrovascular stroma. Uniquely in the PSCT microenvironment, NB cells were found integrated in a non­random fashion. Neuroblastoma cells were never observed in areas with well-differentiated somatic tissue i.e. bone, muscle, gut or areas of other easily identifiable tissue types. Instead, the three cell lines all showed initial growth exclusively occurring in the embryonic loose mesenchymal stroma, resulting in a histology recapitulating NB native presentation in vivo. Whether this reflects the 'open' nature of loose mesenchyme more easily giving space to new cells compared to other more dense tissues, the rigidity of matrix providing physical cues modulating NB characteristics, or if embryonic loose mesenchyme may supply developmental cues that attracted or promoted the integration of NB, remains to be tested. We tentatively hypothesize that mature PSCT provide an embryonic niche well suited for in vivo studies on NB.

Prenatal intrarenal neuroblastoma mimicking a mesoblastic nephroma: a case report.

Mesoblastic nephroma is by far the most frequent intrarenal fetal tumor. To the best of our knowledge, we report the first case of a newborn with an intrarenal neuroblastoma that was discovered prenatally. An intrarenal echogenic and homogenous mass was observed on routine prenatal ultrasonography, corroborated by magnetic resonance imaging, in a 30-week gestation fetus. A male weighing 3280 g was born with elevated blood pressure and cardiac failure. Postnatal ultrasound confirmed a left intrarenal tumor with microcalcifications and perirenal adenopathy. An open total left nephrectomy by laparotomy was performed. The pathologic study reported that the mass was an intrarenal neuroblastoma with local and regional invasion. Immediate postoperative urine analysis revealed a high level of vanillylmandelic acid, and blood samples showed high levels of normetanephrine. The purpose of this report is to demonstrate that prenatal intrarenal neuroblastoma can clinically and radiologically mimick a mesoblastic nephroma. High blood pressure, calcifications, and lymphadenopathy on ultrasound should raise the index of suspicion for a possible malignant process. Preoperative measurement of urinary vanillylmandelic acid (VMA) and metanephrines should be performed if the diagnosis is in doubt.

Concordance for neuroblastoma in monozygotic twins: case report and review of the literature.

The patients were infant male twins born by cesarean delivery following a healthy pregnancy at 36 weeks' gestation to unrelated parents. At 4 months of age, twin 2 presented with hepatomegaly and a right suprarenal mass. Resection of an adrenal tumor and a liver tumor biopsy were performed. Twin 1 had no symptoms at 4 months of age. Screening by abdominal ultrasonography showed multiple masses in the liver but no adrenal mass. Metaiodobenzylguanidine scintigraphy showed positive findings in multiple liver masses. A laparoscopic biopsy for a liver tumor was performed. All primary tumor and liver tumor specimens from twin 2 and the liver tumor of twin 1 had the same histologic classification of neuroblastoma and nearly identical genetic aberrations, including a chromosome gain or loss using array-comparative genomic hybridization. From these clinical and pathologic findings and genetic analyses, we strongly demonstrate the transplacental metastatic spread from twin 2 to twin 1. In the literature, 9 pairs of concordant twin neuroblastomas, including the current twin, have been presented; and the clinical findings of 5 twin pairs may represent placental metastases from one twin with congenital neuroblastoma to the other twin. This study is the first report presenting the possibility of twin-to-twin metastasis in monozygotic twins with neuroblastoma based on an analysis of the clinical features and genetic aberrations.

[Prenatal diagnosis of retroperitoneal neuroblastoma. Case report]. / Diagnóstico prenatal de neuroblastoma retroperitoneal. Reporte de un caso.

Neuroblastoma is the foremost malignant neoplasm of the fetus and neonate. It is a tumor of the sympathetic nervous system that originates from the neural crest which etiology is largely unknown. Due to its general variability in outcome, neuroblastoma has long been considered one of the most enigmatic of cancers. Although technological advances in ultrasonography have possible intrauterine detection, prenatal diagnosis is still a rare event. This kind of tumor has a high morbidity and mortality rate due to the metastatic risk. Early detection of the tumor is critical to improve outcome. We report a case of retroperitoneal neuroblastoma diagnosed at 32 week of gestation.

Prenatal diagnosis and subsequent treatment of an intermediate-risk paraspinal neuroblastoma: case report and review of the literature.

OBJECTIVES: Neuroblastoma is the most common extracranial solid tumor of childhood, and the most common malignancy diagnosed during infancy. In comparison, neonatal neuroblastoma is relatively rare. Improvements in prenatal imaging and widespread use of fetal ultrasonography have led to an increased rate of prenatal diagnoses. METHODS: Case report and literature review. RESULTS: We report a case of an intermediate-risk neuroblastoma, diagnosed at 36 weeks' gestation by ultrasound and subsequently visualized by fetal MRI, that resulted in spinal cord compression and decreased fetal movement. A multidisciplinary team approach resulted in rapid delivery, evaluation, biopsy, staging, and treatment implementation in a successful effort to preserve lower extremity function. CONCLUSION: Prenatal diagnosis of neuroblastoma, management and outcomes are reviewed. Prompt diagnosis can strongly influence perinatal management and improve prognosis.

Spontaneous resolution of an adrenal mass seen on ultrasound at 17 weeks gestation.

We report a congenital neuroblastoma with findings at 17 weeks gestation that was managed expectantly; this represents the earliest reported finding of a congenital neuroblastoma we could find in the English literature.

Tumores fetales: I parte / Fetal tumors: Part I

Se presenta una revisión sistemática y resumida de los diferentes tumores fetales, haciendo énfasis en su diagnóstico prenatal y posibles tratamientos intrauterinos. En esta primera parte se introduce el tema y se analizan tumores del sistema nervioso central, cara y cuello.

Motoneuronal cell death is not correlated with aggregate formation of androgen receptors containing an elongated polyglutamine tract.

Spinal and bulbar muscular atrophy (SBMA) is associated with an abnormal expansion of the (CAG)(n)repeat in the androgen receptor (AR) gene. Similar mutations have been reported in other proteins that cause neurodegenerative disorders. The CAG-coded elongated polyglutamine (polyGln) tracts induce the formation of neuronal intracellular aggregates. We have produced a model to study the effects of potentially 'neurotoxic' aggregates in SBMA using immortalized motoneuronal cells (NSC34) transfected with AR containing polyGln repeats of different sizes [(AR.Q(n = 0, 23 or 46)]. Using chimeras of AR.Q(n) and the green fluorescent protein (GFP), we have shown that aggregate formation occurs when the polyGln tract is elongated and AR is activated by androgens. In NSC34 cells co-expressing the AR with the polyGln of pathological length (AR.Q46) and the GFP we have noted the presence of several dystrophic neurites. Cell viability analyses have shown a reduced growth/survival rate in NSC34 expressing the AR.Q46, whereas testosterone treatment partially counteracted both cell death and the formation of dystrophic neurites. These observations indicate the lack of correlation between aggregate formation and cell survival, and suggest that neuronal degeneration in SBMA might be secondary to axonal/dendritic insults.

In vivo spontaneous neuronal to neuroendocrine lineage conversion in a subset of neuroblastomas.

Neuroblastoma is an embryonal tumor derived from the sympathetic nervous system. Although all neuroblastomas have a neuronal character, a subset of tumors also show evidence of extra-adrenal neuroendocrine differentiation in discrete cell layers. A characterization of the cells of the developing human sympathetic nervous system was performed, identifying growth-associated protein-43, neuropeptide tyrosine, and Bcl-2 as marker genes for sympathetic neurons. Whereas all neuroblastomas express growth-associated protein-43, neuropeptide tyrosine, and Bcl-2, tumors with differentiating cells with neuroendocrine features expressed these genes only in the morphologically immature, proliferating cells. Thus, with neuroendocrine tumor cell differentiation, neuronal marker gene expression vanished and proliferation ceased and was succeeded by expression of chromogranin A/B and insulin-like growth factor-2, markers of neuroendocrine chromaffin differentiation. These tumors appear to provide examples of spontaneous lineage conversion from a neuronal to a neuroendocrine phenotype.