The many faces of neuroblastoma

Pediatric presacral tumors with intraspinal extension: a rare entity with diagnostic challenges

The presacral space is a potential space located between the rectum and the lumbosacral spine. It contains various primitive germ cell types that serve as the origin for a range of tumors. Imaging is crucial in characterizing, assessing the extent of and evaluating the treatment response to these tumors. We report a series of six cases of pediatric presacral tumors with intraspinal extension, including an immature sacrococcygeal teratoma (Altman type II), a malignant sacrococcygeal teratoma (Altman type IV), a neuroblastoma, a rhabdomyosarcoma, a clear cell sarcoma and an Ewing's sarcoma of the ilium. These tumors can be broadly categorized as tumors of germ cell, neuroblastic, mesenchymal and osteogenic origin. Despite overlapping imaging features, a review of the existing literature and careful retrospective observation revealed several distinctive features that aid in the optimal characterization of tumors. These include the tumor's epicenter, the pattern and degree of bone involvement, the status of sacral foramina and neural elements, and internal tumor characteristics such as the presence of fat, calcification, hemorrhage and necrosis.

56 Fe ion exposure increases the incidence of lung and brain tumors at a similar rate in male and female mice

The main deterrent to long-term space travel is the risk of Radiation Exposure Induced Death (REID). The National Aeronautics and Space Administration (NASA) has adopted Permissible Exposure Levels (PELs) to limit the probability of REID to 3% for the risk of death due to radiation-induced carcinogenesis. The most significant contributor to current REID estimates for astronauts is the risk of lung cancer. Recently updated lung cancer estimates from Japan's atomic bomb survivors showed that the excess relative risk of lung cancer by age 70 is roughly four-fold higher in females compared to males. However, whether sex differences may impact the risk of lung cancer due to exposure to high charge and energy (HZE) radiation is not well studied. Thus, to evaluate the impact of sex differences on the risk of solid cancer development post-HZE radiation exposure, we irradiated Rb ^fl/fl ; Trp53 ^fl/+ male and female mice infected with Adeno-Cre with various doses of 320 kVp X-rays or 600 MeV/n ⁵⁶ Fe ions and monitored them for any radiation-induced malignancies. We observed that lung adenomas/carcinomas and esthesioneuroblastomas (ENBs) were the most common primary malignancies in X-ray and ⁵⁶ Fe ion-exposed mice, respectively. In addition, 1 Gy ⁵⁶ Fe ion exposure compared to X-rays led to a significantly higher incidence of lung adenomas/carcinomas (p=0.02) and ENBs (p<0.0001). However, we did not find a significantly higher incidence of any solid malignancies in female mice as compared to male mice, regardless of radiation quality. Furthermore, gene expression analysis of ENBs suggested a distinct gene expression pattern with similar hallmark pathways altered, such as MYC targets and MTORC1 signaling, in X-ray and ⁵⁶ Fe ion-induced ENBs. Thus, our data revealed that ⁵⁶ Fe ion exposure significantly accelerated the development of lung adenomas/carcinomas and ENBs compared to X-rays, but the rate of solid malignancies was similar between male and female mice, regardless of radiation quality.

Identification of a novel eighteen-gene signature of recurrent metastasis neuroblastoma

Neuroblastoma is the most common malignant tumor in childhood, and metastases occur in more than 30% patients. Recurrent metastasis is the main cause of poor prognosis and high mortality in neuroblastoma. In this regard, there is still a lack of sufficient biomarkers and effective therapies. Therefore, we performed a multi-omics analysis of neuroblastoma patients from Therapeutically Applicable Research To Generate Effective Treatments (TARGET). With clinical relapse site information, tumor samples derived from the primary site were divided into recurrent metastasis and primary tumor groups. The initial gene signature was obtained by comparing RNA-Seq and copy number variation differences. Survival data was used to further filter prognosis-related genes. This 18-gene signature consists of three clusters: tumor suppression, cell proliferation, and immunity. A super enhancer is involved in the enhanced expression of NCAPG in cluster2 together with IRF3. Based on the gene signature expression in primary neuroblastoma, it is possible to predict tumor metastasis before it occurs. According to the anticancer drug dataset of Genomics of Drug Sensitivity in Cancer (GDSC), vinorelbine and docetaxel were predicted to have high sensitivity against recurrent metastatic neuroblastoma. In conclusion, our study offers a novel metastasis biomarker and helps understand the mechanisms of tumor recurrent metastasis. KEY MESSAGES: We identified a novel eighteen-gene signature of recurrent metastasis neuroblastoma and build risk and classification models. We dissected the regulatory role of NCAPG in signatures. We found immune exhaustion and immunosuppression in recurrent metastasis neuroblastoma. Vinorelbine and docetaxel were predicted to have high sensitivity against recurrent metastatic neuroblastoma.

A retrospective evaluation of the presentation, prognostic factors and outcomes of neuroblastoma in Ugandan children

Neuroblastoma (NB) is the most common extracranial solid tumor of childhood. The complete burden and outcomes in Uganda are unknown. The study was a multicenter retrospective chart review of children aged between 0 to 15 years diagnosed with NB from 2010 to 2020. Demographic, clinical and tumor-related characteristics were extracted for analysis. Kaplan-Meier survival curves and Cox regression models were used to determine the one-year overall survival (OS) and identify prognostic factors. Seventy-five patients were evaluated, with a median age at diagnosis of 48 months (IQR 26-108 months). Fever (74.7%), weight loss (74.7%), high blood pressure (70.3%) and abdominal swelling/mass (65.3%) were the most common features at diagnosis. Suprarenal tumors (52%) and stage 4 disease (70.7%) were also common. The one-year OS was 60.0% (95%CI 56.8%; 64.3%) with a median survival time of 12.6 months (95% CI: 8.1; 20.8). The one-year OS for non-metastatic and metastatic disease was 67.3% and 42.6% (p = 0.11) respectively. Leukocytosis (p < 0.001) at diagnosis was of prognostic significance while clinical remission after induction chemotherapy (p < 0.001) provided survival advantages. Children who received maintenance chemotherapy had a longer median survival time of 38.5 months (range 10.8-69.5). Age (p = 0.001), lung metastasis (p < 0.001), and leukocytosis (p < 0.001) remained significant on multivariate analysis. In this Ugandan study, leukocytosis was a clinical predictor of prognosis, metastatic disease had management challenges and maintenance chemotherapy prolonged the survival time but not OS.

A Rare Case Report of Unilateral Maxillary Mass from Adrenal Neuroblastoma

Neuroblastoma is the most common extracranial neoplasm among paediatric patients, which arises from ectodermal neural crest cells. The most frequent primary site of neuroblastoma arises from retroperitoneum, specifically in the adrenal medulla. We present a rare case of adrenal neuroblastoma metastasis to maxillary sinus in a 20 month-old boy presenting with right maxillary swelling for the past 2 months. Computed tomography (CT) scan of paranasal sinus demonstrated right maxillary mass. A biopsy performed via a sublabial approach, surprisingly revealed neuroblastoma. Subsequent further workup depicted a huge right adrenal tumour. He was diagnosed with adrenal neuroblastoma stage 4 and treated with chemotherapy and surgical resection.

Continuous and progressive 'wash-in' without 'wash-out' of contrast in adrenal mass: a useful feature of ganglioneuroma

Computed tomography (CT) scan is a useful and widely performed diagnostic modality to evaluate adrenal masses. Nature of the mass determines the degree of attenuation both in unenhanced and in different phases of contrast enhancement. Benign neurogenic tumours like ganglioneuroma mimicks pheochromocytoma and adrenocortical carcinoma in non-contrast CT scan. The 'adrenal protocol' routinely calculates the wash-out pattern at delayed venous phase (DVP) (15 min) following contrast administration to differentiate majority of benign masses from the malignant ones. Ganglioneuromas typically exhibit continuous wash-in of contrast where enhancement gradually increases to attain its peak in DVP. Such wash-in pattern is different from the wash-out pattern observed in pheochromocytomas or adrenocortical adenomas or carcinomas. Presence of this wash-in pattern provides a useful clue to the clinician for underlying ganglioneuroma in hormonally inactive adrenal masses with suspicious morphological appearances. This wash-in pattern also effectively rules out any malignant potential of ganglioneuroma, and thus helps in preoperative decision-making.

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.

Biochemical testing for neuroblastoma using plasma free 3-O-methyldopa, 3-methoxytyramine, and normetanephrine

BACKGROUND

Neuroblastoma, the most common extracranial solid tumor of childhood, produces catecholamines that are metabolized within tumor cells. Homovanillic acid (HVA) and vanillylmandelic acid (VMA), the end products of catecholamine metabolism, have limited accuracy for testing of the tumors. This study assessed whether metabolites produced in earlier steps of catecholamine metabolism might offer improved diagnostic accuracy over urinary HVA and VMA.

PROCEDURE

Plasma concentrations of 3-methoxytyramine, normetanephrine, and metanephrine were measured in two pediatric cohorts: (i) 96 children with confirmed neuroblastoma and (ii) 41 children with signs and symptoms of a catecholamine-producing tumor or other neoplasms and in whom neuroblastoma was excluded. Additional measurements of plasma 3-O-methyldopa and relationships of metabolites to MYCN amplification were examined in patient subgroups.

RESULTS

Overall, 94 of the 96 patients with neuroblastoma had concentrations of 3-methoxytyramine or normetanephrine above age-specific upper limits of reference intervals, providing a diagnostic sensitivity of 97.9% that was higher (P < 0.0001) than that of 82.2% for HVA and VMA. One of the two patients with normal plasma results showed an elevation of plasma 3-O-methyldopa. Diagnostic specificities were, respectively, 95.1% and 84.8%. Areas under receiver-operating characteristic curves confirmed the superior diagnostic power of the plasma than the urinary test (0.994 vs 0.945; P = 0.0095). Ratios of plasma 3-methoxytyramine to normetanephrine were 7.2-fold higher (P < 0.0001) for patients who had neuroblastomas with MYCN amplification than without MYCN amplification.

CONCLUSIONS

Measurements of plasma 3-methoxytyramine and normetanephrine provide a highly accurate diagnostic test for neuroblastoma and also offer potential for prognostic risk stratification.

Overall survival for neuroblastoma in South Africa between 2000 and 2014

BACKGROUND

Outcome data for neuroblastoma in sub-Saharan Africa are minimal, whereas poor outcome is reported in low- and middle-income countries. A multi-institutional retrospective study across South Africa was undertaken to determine outcome.

METHODS

Patients treated between January 2000 and December 2014 in nine South African pediatric oncology units were included. Kaplan-Meier curves and Cox regression models were employed to determine two-year survival rates and to identify prognostic factors.

RESULTS

Data from 390 patients were analyzed. The median age was 39.9 months (range, 0-201 months). The majority presented with stage 4 disease (70%). The main chemotherapy regimens were OPEC/OJEC (44.8%), St Jude NB84 protocol (28.96%), and Rapid COJEC (22.17%). Only 44.4% had surgery across all risk groups, whereas only 16.5% of high-risk patients received radiotherapy. The two-year overall survival (OS) for the whole cohort was 37.6%: 94.1%, 81.6%, and 66.7%, respectively, for the very-low-risk, low-risk, and intermediate-risk groups and 27.6% for the high-risk group (P < 0.001, 95% CI). The median survival time for the whole group was 13 months (mean, 41.9 months; range, 0.1-209 months). MYCN-nonamplified patients had a superior two-year OS of 51.3% in comparison with MYCN-amplified patients at 37.3% (P = 0.002, 95% CI).

CONCLUSIONS

Limited disease had an OS comparable with high-income countries, but advanced disease had a poor OS. South Africa should focus on early diagnosis and implementation of a national protocol with equitable access to treatment.

Neuroblastoma image-defined risk factors in adrenal neuroblastoma: role of radiologist

Neuroblastoma, one of the most common extracranial solid malignancies in children, is often localized in the adrenal glands (49%). The staging system for prognostic purpose was one of the first points of disagreement, which led to the International Neuroblastoma Staging System (INSS) of 1986, revised in 1989, which relies on surgical staging. The limit of this classification was the different surgical resection, also done at interval times from diagnosis. To overcome this difficulty, a new staging system was made based on preoperative imaging by the International Neuroblastoma Risk Group (INRG) in 2009. This new staging system uses 20 Image-Defined Risk Factors (IDRFs) across multiple organ systems. The scope of this IDRFs is to predict surgical outcomes and, in addition with clinical data, to provide risk stratification. The INRG Staging System (INRGSS) relies on Imaging-Defined Risk Factors (IDRFs) that are determined before surgery or other therapy. With the application of the INRGSS the radiologist's role in staging children with neuroblastoma increased. The review provides an overview of the INRGSS and the IDRFs in adrenal neuroblastoma.

Small molecule inhibitor agerafenib effectively suppresses neuroblastoma tumor growth in mouse models via inhibiting ERK MAPK signaling

Neuroblastoma (NB) is the most common extracranial solid tumor in early childhood. Despite intensive multimodal therapy, nearly half of children with high-risk disease will relapse with therapy-resistant tumors. Dysregulation of MAPK pathway has been implicated in the pathogenesis of relapsed and refractory NB patients, which underscores the possibility of targeting MAPK signaling cascade as a novel therapeutic strategy. In this study, we found that high expressions of RAF family kinases correlated with advanced tumor stage, high-risk disease, tumor progression, and poor overall survival. Targeted inhibition of RAF family kinases with the novel small molecule inhibitor agerafenib abrogated the activation of ERK MAPK pathway in NB cells. Agerafenib significantly inhibited the cell proliferation and colony formation ability of NB cells in vitro, and its combination with traditional chemotherapy showed a synergistic pro-apoptotic effect. More importantly, agerafenib exhibited a favorable toxicity profile, potently suppressed tumor growth, and prolonged survival in NB mouse models. In conclusion, our preclinical data suggest that agerafenib might be an effective therapeutic agent for NB treatment, both as a single-agent and in combination with chemotherapy.

Global Health Perspective in Sarcomas and Other Rare Cancers

Sarcomas, rare and heterogenous malignancies that comprise less than 1% of all cancers, have poor outcomes in the metastatic and refractory setting. Their management requires a multidisciplinary approach that consists of medical and surgical oncologists, radiation oncologists, and pathologists as well as ancillary support. In addition to systemic treatments, most patients will require surgical resection and radiation therapy, which mandates the use of the latest technologies and specialized expertise. Management guidelines have been developed in high-income countries, but their applicability in low-income countries, where resources may be limited, remains a challenge. In this article, we propose the best possible evidence-based practices specifically for income-constrained settings to overcome this challenge. In addition, we review the different methods that can be used in low-income countries to access new and expensive treatments, which often times carry prohibitive costs for these areas.

Imaging of the limping child

Limping is a challenging symptom in the pediatric patient as the diagnosis can range from traumatic, malformative, infectious/inflammatory and neoplastic diseases. In this paper, we propose a schematic imaging algorithm to the limping child in three different age groups (Toddler: 1-3years, child: 4-10 years; adolescent: 11-16 years) based on presence of signs of infection, any specific localization of pain, and history of trauma. In this setting, the most common imaging pitfalls are also summarised. Finally, a literature review of the main differential causes of limping in the pediatric patient is reported.

Irritable Hip as the Inaugural Symptom for Neuroblastoma

CASE REPORT

A four-year-old girl presented with fever and a painful limp in the left hip. Pain characteristics and anemia detected in the blood analyses were the first warning signs that the hip process was not standard. Although the primary suspicion was of septic arthritis, a CT scan of the abdomen revealed an adrenal neuroblastoma.

CONCLUSION

The presenting signs of neuroblastoma are commonly atypical. About 25% of presentations are orthopedic and mimic a variety of severe orthopedic conditions. The most important clinical dilemma is distinguishing benign and self-limiting disorders from septic or malignant processes.

Diagnostic imaging of benign and malignant neck masses in children-a pictorial review

Neck masses are frequently encountered in pediatric medicine, and can present a diagnostic dilemma for the clinicians involved. There are several means by which neck masses in children can be subdivided, for example by age at presentation, anatomical location including compartments and fascia of the neck, their classical appearance when imaged, or by etiology. When imaging children the clinicians must be mindful of radiation exposure and as such ultrasound (US) is often attempted first. Cross sectional imaging can be helpful for problem solving with CT being particularly useful for assessing the patient in more acute scenarios, for example when there is airway compromise. Nuclear medicine scintigraphy has a role in specific circumstances and can aid in staging in the presence of malignancy. If required, additional acquisition by means of magnetic resonance imaging (MRI) and computed tomography (CT) can be considered. This pictorial review describe the diagnostic imaging of (I) congenital and Developmental Pathologies, including thyroglossal duct cyst, branchial cleft cyst, cystic hygroma, dermoid cyst, thymic cyst and ectopic thymus; (II) neoplastic lesions, including hemangiomas and vascular malformations, pilomatrixoma, neurofibroma, neuroblastoma, rhabdomyosarcoma, papillary thyroid cancer, lymphoma & leukemia; (III) neck masses of Infective causes, including lymphadenitis, retropharyngeal and peritonsilar abscess, salivary gland inflammation; and (IV) other miscellaneous lesions, including ranula, sternocleidomastoid fibromatosis coli, and goiter. Neck masses are common in the pediatric population with a broad and varied differential; malignant etiologies are less frequently encountered when compared with adults but an awareness of its potential is important when reviewing imaging.

Pediatric Chest Radiographs: Common and Less Common Errors

OBJECTIVE

Radiographic imaging of the pediatric chest presents several unique challenges and nuances, stemming from congenital variants and pathologic processes specific to this population. Errors in interpretation may lead to inappropriate further imaging, incurring additional radiation exposure and cost, as well as psychologic effects on the patients and their families.

CONCLUSION

Here, we aim to highlight some common and less common pitfalls in pediatric chest radiography, as well as some tools for avoiding potential mistakes.

A Novel Anticancer Agent, 8-Methoxypyrimido[4',5':4,5]thieno(2,3-b) Quinoline-4(3H)-One Induces Neuro 2a Neuroblastoma Cell Death through p53-Dependent, Caspase-Dependent and -Independent Apoptotic Pathways

Neuroblastoma is the most common cancer in infants and fourth most common cancer in children. Despite recent advances in cancer treatments, the prognosis of stage-IV neuroblastoma patients continues to be dismal which warrant new pharmacotherapy. A novel tetracyclic condensed quinoline compound, 8-methoxypyrimido [4',5':4,5]thieno(2,3-b) quinoline-4(3H)-one (MPTQ) is a structural analogue of an anticancer drug ellipticine and has been reported to posses anticancer property. Study on MPTQ on neuroblastoma cells is very limited and mechanisms related to its cytotoxicity on neuroblastoma cells are completely unknown. Here, we evaluated the anticancer property of MPTQ on mouse neuro 2a and human SH-SY5Y neuroblastoma cells and investigated the mechanisms underlying MPTQ-mediated neuro 2a cell death. MPTQ-mediated neuro 2a and SH-SY5Y cell deaths were found to be dose and time dependent. Moreover, MPTQ induced cell death reached approximately 99.8% and 90% in neuro 2a and SH-SY5Y cells respectively. Nuclear oligonucleosomal DNA fragmentation and Terminal dUTP Nick End Labelling assays indicated MPTQ-mediated neuro 2a cell death involved apoptosis. MPTQ-mediated apoptosis is associated with increased phosphorylation of p53 at Ser15 and Ser20 which correlates with the hyperphosphorylation of Ataxia-Telangiectasia mutated protein (ATM). Immunocytochemical analysis demonstrated the increased level of Bax protein in MPTQ treated neuro 2a cells. MPTQ-mediated apoptosis is also associated with increased activation of caspase-9, -3 and -7 but not caspase-2 and -8. Furthermore, increased level of caspase-3 and cleaved Poly (ADP Ribose) polymerase were observed in the nucleus of MPTQ treated neuro 2a cells, suggesting the involvement of caspase-dependent intrinsic but not extrinsic apoptotic pathway. Increased nuclear translocation of apoptosis inducing factor suggests additional involvement of caspase-independent apoptosis pathway in MPTQ treated neuro 2a cells. Collectively, MPTQ-induced neuro 2a cell death is mediated by ATM and p53 activation, and Bax-mediated activation of caspase-dependent and caspase-independent mitochondrial apoptosis pathways.

Application of imaging modalities for evaluating neuroblastoma

Neuroblastoma are the most common extracranial solid tumor of childhood. It is a malignancy derived from embryonic neural crest cells of the peripheral sympathetic nervous system that demonstrates remarkably heterogenous clinical and biological behavior ranging from spontaneous regression to inexorable progression with fatal outcomes. Various imaging modalities, including plain radiograph, ultrasound, computed tomography (CT), magnetic resonance imaging, bone scintigraphy, metaiodobenzylguanidine scintigraphy, and positron emission tomography/CT have been used to diagnose primary and metastatic neuroblastoma. In this article, we review the application of various imaging modalities to better define and recognize their role in the diagnosis and follow-up of neuroblastoma.

Adrenal imaging: a comprehensive review

The discovery of an incidental adrenal mass (adrenal incidentaloma) continues to rise with the increasing use of cross-sectional imaging. Although most adrenal lesions are benign and asymptomatic, radiologists should guide evaluation of these lesions, whether benign or malignant. This article reviews the various imaging techniques used to evaluate adrenal masses and their relative strengths and weaknesses. It focuses on the most prevalent adrenal pathologies and their typical imaging characteristics, and concludes with a brief discussion of developing techniques, including diffusion-weighted imaging and dual-energy CT.

Adult pancreatic neuroblastoma, an unusual site and fatal outcome

In this report, we describe a classic case of stroma rich neuroblastoma, nodular type in a 22 year old female presented with a pancreatic mass. This rare and unusual presentation elicits several differential diagnostic categories including solid pseudopapillary tumor, pancreatic endocrine tumor, pancreatoblastoma and PNET. In this report, we tried to differentiate between them depending on the histopathological features and using panel of epithelial and neuroendocrine markers. Although of the rarity of pancreatic neuroblastoma as a primary site of origin, however it should be considered in the differential diagnosis of pancreatic masses in children and young adult. Neuropil and ganglionic differentiation are helpful features to recognize neuroblastoma and differentiate them from other small blue cell tumors. The fatal outcome of adult neuroblastoma confirming the independence of age as a prognostic factor in this neoplasm regardless of stage and histology.

Clinical presentations and imaging findings of neuroblastoma beyond abdominal mass and a review of imaging algorithm

Neuroblastoma is one of the most common malignant neoplasms in childhood. The most common clinical presentation of this tumour is abdominal mass. However, affected children may have various clinical presentations as a result of disseminated metastatic disease or associated paraneoplastic syndromes at the time of diagnosis. In this article we have outlined the imaging findings in seven patients with "extra-abdominal" presentation of neuroblastoma and the pitfalls in making the correct diagnosis. The purpose of this pictorial review is to alert the general radiologist to the possible presentations of this common childhood malignancy to derive early detection and diagnosis.

Calvarial masses of infants and children. A radiological approach

Children frequently present with asymptomatic head lumps that have been discovered by their parents or by their hairdressers. Other children present with painful lumps or symptoms of intra-cranial masses with calvarial involvement. Imaging plays an important role in the diagnosis of such masses and in subsequent surgical planning. We present a review of the types of lesion that may present in these ways.

Adult neuroblastoma: radiologic and clinicopathologic features

PURPOSE

The purpose of the current study was to define the imaging findings of adult neuroblastoma (ANB) and correlate them with clinicopathologic features.

MATERIALS AND METHODS

The CT scans and MR images of six patients with histologically confirmed ANB (mean age, 49 years) were retrospectively analyzed.

RESULTS

The arising sites of tumors included the retroperitoneum (n = 2), pelvis (n = 2), anterior mediastinum (n = 1), and adrenal gland (n = 1). The common CT finding was poorly marginated and heterogeneous mass without calcification. Cystic components were often found. On contrast-enhanced CT or MR images, tumors showed heterogeneous enhancement. On T2-weighted images, all masses demonstrated predominantly hyper signal intensity relative to skeletal muscle and the images showed heterogeneous appearance with focal areas of high intensity interspersed with septations of low signal intensity. Soft tissue masses with bone involvement were identified in one case on MR images. The CT findings in one tumor originating from mediastinum were similar to those of tumors arising from other sites.

CONCLUSION

ANB is an uncommon malignancy that often pursues an aggressive clinical course, involves multiple sites, and has a poor prognosis. Tumors usually manifest on CT or MR images as a poorly demarcated mass mainly in the retroperitoneum and pelvis. Imaging studies can depict aggressive characteristics and disease extent of ANB.

Neurogenic tumors of the neck

Neurogenic tumors of the neck occur in children and adults. Important parameters to aid in the differential diagnosis are age at presentation, location, and a history of NF or multiple endocrine neoplasia. Schwannoma is the most common solitary neurogenic tumor in the neck and is usually seen in patients between 20 and 50 years of age. The plexiform neurofibroma and multiple localized neurofibromas are characteristic of NF1. MPNSTs are uncommon aggressive lesions that can arise de novo in patients with NF (10% to 30%) and postirradiation. Neuroblastic tumors consist of neuroblastoma, ganglioneuroblastoma, and ganglioneuroma. These tumors typically arise in the chest and abdomen but occasionally present as a primary neck mass. A neck mass with a histologic diagnosis of neuroblastoma is, however, more commonly metastatic from an abdominal neuroblastoma.

Spectrum of neurogenic tumors in the thorax: CT and pathologic findings

Neurilemomas and neurofibromas appear as round soft tissue masses at CT. Variable enhancement with either homogeneity or heterogeneity is seen in neurilemomas. Attenuation of the tumors on enhanced CT depends on histology: the extent of Antoni A or B tissue and the amount of myxoid or cystic degeneration or hemorrhage. Neurofibromas are usually homogeneous low attenuation lesions on unenhanced CT. They show homogeneous enhancement or early central blush on enhanced scan. The extent of enhancement depends on the proportions of tumor components: nerve sheath cells, collagen bundles, and areas of myxoid degeneration. Malignant nerve sheath tumors show variable attenuation. Bony destruction, pleural effusion, and metastatic pulmonary nodules may also occur. Ganglioneuromas appear as oblong homogeneous low attenuation lesions on both enhanced and unenhanced CT. This low attenuation is due to their pathologic components, with an abundant amount of myxoid matrices and a relatively small amount of ganglion cells. Neuroblastomas appear as aggressive soft tissue lesions with calcification. Ganglioneuroblastomas may appear with features in between those of ganglioneuromas and neuroblastomas. The typical location of the posterior mediastinum or the aortopulmonary window and high enhancement with administration of contrast medium at CT suggest the diagnosis of paragangliomas.

Unusual CNS presentation of neuroblastoma

Neuroblastoma is a common tumor of childhood, usually occurring in children under 4 years of age [1]. We report a case of a 10-year old child who initially presented with a large calvarial mass representing a solitary site of metastasis from an occult adrenal neuroblastoma. The sunburst pattern of the calvarial metastasis noted in this case is rarely seen with neuroblastoma. The age of our patient, solitary focus of metastasis at presentation, and imaging appearance of the tumor are very uncommon findings of neuroblastoma.

Diagnosis and follow-up of neuroblastoma by means of iodine-123 metaiodobenzylguanidine scintigraphy and bone scan, and the influence of histology

The purpose of this work was to compare technetium-99m-diphosphono-propanedicarboxylate (DPD) and iodine-123-metaiodobenzylguanidine (MIBG) scans in the diagnosis and follow-up of neuroblastoma, and to study the role of histological differentiation in the uptake of MIBG. The uptake of MIBG and of DPD were studied retrospectively in 27 patients with neuroblastoma (primary, residual and recurrent tumours as well as bone and bone marrow metastases). The findings were related to the histological classification of the tumours as neuroblastoma (N1), differentiating neuroblastoma (N2) or ganglioneuroblastoma (N3). Uptake of MIBG by the primary tumour occurred in 17 of 19 patients, either at diagnosis or during follow-up. There were only two false-negatives with MIBG, both of which were N3. Ten patients were studied preoperatively with both MIBG and DPD. The primary tumour showed MIBG uptake in nine of the ten and DPD uptake in eight of them. Thirty-five sites of cortical bone metastasis were shown in eight patients by both MIBG and DPD, 12 sites in seven patients by MIBG only and seven sites in five patients by DPD only. In 14 patients both MIBG and bone scan were negative. Overall, MIBG demonstrated more lesions than DPD. Retrospectively several hot spots seen only with the bone scan are to be considered as false-positive. The highest incidence of false-negative MIBG and bone scans was observed in ganglioneuroblastoma with a predominance of the more mature component (ganglioneuroma).