Lung involvement in neuroblastoma: incidence and characteristics

Serous fluid: Metastatic sarcomas, melanoma, and other non-epithelial neoplasms

While most tumors metastatic to the serous membranes are of epithelial origin, cytologists should be aware that non-epithelial neoplasms can also cause malignant effusions including sarcomas, melanomas, germ cell tumors, and, more rarely, brain tumors. The differential diagnosis of a malignant effusion is accordingly broad, especially for the small round blue cell tumors that includes not only mesenchymal tumors, but also non-mesenchymal tumors, such as neuroblastoma and Wilms tumor. Diagnosing non-epithelial malignancies in effusion specimens based entirely upon their cytomorphologic features is difficult because these neoplasms often exhibit considerable morphological overlap and their cytomorphology can differ from the original tumor. As malignant cells have a tendency to round up in body fluids these non-epithelial neoplasms can therefore mimic reactive mesothelial cells and metastatic adenocarcinoma. The use of ancillary studies including immunostaining, FISH, and molecular studies is thus often critical to reach a definitive diagnosis. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Diagnostic Cytopathology of Serous Fluids.

Pediatric thoracic mass lesions: Beyond the common

Thoracic mass lesions can be categorized as originating in one of the three major compartments: a) chest wall and pleura, b) lung parenchyma and airways, c) mediastinum. While some of these, such as lymphoma, are common in both children and adults, others are rare and unique to childhood. The goal of this review is to familiarize radiologists with unusual but distinctive mass lesions of the pediatric thorax.

Venous Tumor Thrombosis and Pulmonary Metastases in a Case of Adrenal Neuroblastoma—Occurrence of Two Rare Manifestations in a Single Patient: Case Report and Review of Literature

Unlike other pediatric extra cranial solid neoplasms, neuroblastomas have very low incidence of pulmonary metastases. Neuroblastomas also tend to encase rather than infiltrate the major vessels with very low incidence of tumor thrombus. Even in cases with inferior vena cava tumor thrombosis, pulmonary metastases are a rare occurrence. These patients usually show widespread disseminated disease at presentation. We present a rare case of adrenal neuroblastoma with tumor thrombus and bilateral pulmonary metastases at presentation. This presentation can be confused with adrenocortical carcinoma and differentiating between the two is essential for further management.

Cancer Cell Dormancy in Metastasis

Recurrent metastasis following extended periods of disease-free survival remains a common cause of morbidity and mortality for many cancer patients. Recurrence is thought to be mediated by tumor cells that escaped the primary site early in the disease course and colonize distant organs. In these locations, cells adapt to the local environment, entering a state of long-term dormancy in which they can resist therapy. Then, through mechanisms that are poorly understood, a proportion of these cells are reactivated and become proliferative, forming lethal metastases. Here, we discuss disseminated tumor cell dormancy in recurrent metastasis. We discuss mechanisms known to control entrance of cells into dormancy, highlighting the relevant microenvironments or "niches" in which these cells reside and mechanisms known to be involved in dormant cell reactivation. Finally, we consider emerging therapeutic approaches aimed at eradicating residual disease and preventing metastatic relapse.

Comparative Analysis of Flow Cytometry and Cytomorphology for Neuroblastoma Cell Detection in Effusion and Bone Marrow Specimens

Background：Neuroblastoma (NB) frequently metastasizes to the bone marrow (BM), pleural and peritoneal cavities. The detection of NB cells in the BM and effusion specimens is important in clinical staging. Objective: The aim of this study was to compare the ability of flow cytometry (FCM) and cytomorphology (CM) in detecting NB cells. Materials and methods：From 21 patients with suspected NB metastasis, BM and effusion specimens were analyzed by FCM and CM. Results：A total of 16 effusion (76.2%) and 9 BM (42.9%) specimens were classified by FCM as positive for malignancy. CM revealed 12 (57.1%) and 9 (42.9%) positive effusion and BM specimens, respectively. There were three effusions detected by CM but not by FCM. There was no significant differences between FCM and CM in the detection of NB cells in effusions (p = 0.344). Conclusions：FCM can be used as an adjunct to CM for the detection of NB cells in effusion specimens.

Pulmonary Metastasectomy in Pediatric Solid Tumors

Metastatic disease and the complications of treating metastatic disease are the primary causes of mortality in children with solid malignancies. Nearly 25% of children with solid tumors have metastatic disease at initial diagnosis and another 20% develop metastases during or after treatment. The most common location of these metastases is the lung. The role of surgery in metastatic disease depends greatly on the histology of the primary. In general, tumors that are refractory to adjuvant therapies are most appropriate for pulmonary metastasectomy. This article will summarize the indications for metastasectomy in pediatric solid tumors and discuss the ongoing debate over the technique of metastasectomy in osteosarcoma.

Primary Pediatric Intracranial Neuroblastoma: A Report of Two Cases

Neuroblastoma is the most common pediatric extracranial solid malignancy. It has a high propensity for spread, especially to the bones and lymph nodes. The involvement of central nervous system is uncommon and most of the cases are restricted to the spine. Primary intracranial neuroblastoma is extremely rare and very few cases have been described in the available literature. We report two cases of primary intracranial neuroblastoma in pediatric age group.

The Beta Subunit of Hemoglobin (HBB2/HBB) Suppresses Neuroblastoma Growth and Metastasis

Soluble pulmonary factors have been reported to be capable of inhibiting the viability of cancer cells that metastasize to the lung, but the molecular identity was obscure. Here we report the isolation and characterization of the beta subunit of hemoglobin as a lung-derived antimetastatic factor. Peptide mapping in the beta subunit of human hemoglobin (HBB) defined a short C-terminal region (termed Metox) as responsible for activity. In tissue culture, both HBB and murine HBB2 mediated growth arrest and apoptosis of lung-metastasizing neuroblastoma cells, along with a variety of other human cancer cell lines. Metox acted similarly and its administration in human tumor xenograft models limited the development of adrenal neuroblastoma tumors as well as spontaneous lung and bone marrow metastases. Expression studies in mice indicated that HBB2 is produced by alveolar epithelial and endothelial cells and is upregulated in mice bearing undetectable metastasis. Our work suggested a novel function for HBB as a theranostic molecule: an innate antimetastasis factor with potential utility as an anticancer drug and a biomarker signaling the presence of clinically undetectable metastasis. Cancer Res; 77(1); 14-26. ©2016 AACR.

Surgical treatment of pulmonary metastases in pediatric solid tumors

Most children who succumb to solid malignancies do so because of the burden of metastatic disease or due to complications associated with the therapy administered to treat metastatic disease. Approximately one-quarter of children with solid tumors will present with metastatic disease, and an additional 20% ultimately develop metastatic disease, most commonly in the lung. The role of surgery in the treatment of metastatic solid tumors, given its disseminated nature, is not intuitive, yet there are circumstances in which surgical resection of metastatic disease can potentially be curative. However, the utility of surgery is very much dependent on histology, and generally is most appropriate for those malignancies with histologies that are refractory to other adjuvant therapies.

Primary renal neuroblastoma with metastasis and matrix metalloproteinase-14 expression

We herein report the rare case of a 4-year-5-month-old boy who presented with primary renal neuroblastoma. The patient developed repeated lung and liver metastatic recurrences, but, following a combination of chemotherapy, radiation therapy and aggressive surgical resection, the patient is now in remission. To investigate the pathogenesis of lung metastasis, immunohistochemistry was performed for matrix metalloproteinase-9 and -14 (MMP-9 and MMP-14), molecular markers of invasion, metastasis and angiogenesis in neuroblastoma. In the present case, MMP-9 expression was not observed, but MMP-14 expression was detected in the primary lesion and was more highly expressed in the metastatic lesion compared with the primary one. Given the MMP-14 staining in other cases, expression of MMP-14 may be associated with the aggressiveness of the tumor. This suggests that selected clones with high MMP-14 expression in the primary tumor might metastasize and form MMP-14-rich lesions.

The CXCR4/CXCR7/CXCL12 Axis Is Involved in a Secondary but Complex Control of Neuroblastoma Metastatic Cell Homing

Neuroblastoma (NB) is one of the most deadly solid tumors of the young child, for which new efficient and targeted therapies are strongly needed. The CXCR4/CXCR7/CXCL12 chemokine axis has been involved in the progression and organ-specific dissemination of various cancers. In NB, CXCR4 expression was shown to be associated to highly aggressive undifferentiated tumors, while CXCR7 expression was detected in more differentiated and mature neuroblastic tumors. As investigated in vivo, using an orthotopic model of tumor cell implantation of chemokine receptor-overexpressing NB cells (IGR-NB8), the CXCR4/CXCR7/CXCL12 axis was shown to regulate NB primary and secondary growth, although without any apparent influence on organ selective metastasis. In the present study, we addressed the selective role of CXCR4 and CXCR7 receptors in the homing phase of metastatic dissemination using an intravenous model of tumor cell implantation. Tail vein injection into NOD-scid-gamma mice of transduced IGR-NB8 cells overexpressing CXCR4, CXCR7, or both receptors revealed that all transduced cell variants preferentially invaded the adrenal gland and typical NB metastatic target organs, such as the liver and the bone marrow. However, CXCR4 expression favored NB cell dissemination to the liver and the lungs, while CXCR7 was able to strongly promote NB cell homing to the adrenal gland and the liver. Finally, coexpression of CXCR4 and CXCR7 receptors significantly and selectively increased NB dissemination toward the bone marrow. In conclusion, CXCR4 and CXCR7 receptors may be involved in a complex and organ-dependent control of NB growth and selective homing, making these receptors and their inhibitors potential new therapeutic targets.

The metastatic microenvironment: lung-derived factors control the viability of neuroblastoma lung metastasis

Recent data suggest that the mechanisms determining whether a tumor cell reaching a secondary organ will enter a dormant state, progress toward metastasis, or go through apoptosis are regulated by the microenvironment of the distant organ. In neuroblastoma, 60-70% of children with high-risk disease will ultimately experience relapse due to the presence of micrometastases. The main goal of this study is to evaluate the role of the lung microenvironment in determining the fate of neuroblastoma lung metastases and micrometastases. Utilizing an orthotopic mouse model for human neuroblastoma metastasis, we were able to generate two neuroblastoma cell populations-lung micrometastatic (MicroNB) cells and lung macrometastatic (MacroNB) cells. These two types of cells share the same genetic background, invade the same distant organ, but differ in their ability to create metastasis in the lungs. We hypothesize that factors present in the lung microenvironment inhibit the propagation of MicroNB cells preventing them from forming overt lung metastasis. This study indeed shows that lung-derived factors significantly reduce the viability of MicroNB cells by up regulating the expression of pro-apoptotic genes, inducing cell cycle arrest and decreasing ERK and FAK phosphorylation. Lung-derived factors affected various additional progression-linked cellular characteristics of neuroblastoma cells, such as the expression of stem-cell markers, morphology, and migratory capacity. An insight into the microenvironmental effects governing neuroblastoma recurrence and progression would be of pivotal importance as they could have a therapeutic potential for the treatment of neuroblastoma residual disease.

Pancreatic involvement in neuroblastoma with radiologic-pathologic correlation: a single-institution experience

OBJECTIVE

Pancreatic involvement in neuroblastoma is extremely rare, with few cases reported in the literature. We present imaging findings of pancreatic involvement in neuroblastoma with clinical and pathologic correlation in the largest documented series to date.

SUBJECTS AND METHODS

We prospectively reported pancreatic involvement evident on multimodality imaging in neuroblastoma patients presenting to our institution from 1997 to 2011. Lesions were classified according to location within the pancreas, and imaging features were correlated with cytogenetic and surgicopathologic findings.

RESULTS

Neuroblastoma involving the pancreas was evident on imaging of seven of 1031 patients (mean age, 6.6 years). One patient had pancreatic involvement at presentation, and six developed pancreatic disease at relapse or disease progression. Pancreatic lesions were most frequently initially identified on concurrent CT and (123)I-metaiodobenzylguanidine scintigraphy, and additional lesions initially were found on MRI and ultrasound. Five of seven patients had focal lesions, one had diffuse pancreatic involvement, and one had pancreatic extension from contiguous disease. The distribution of lesions favored the pancreatic body and tail. All patients had International Neuroblastoma Staging System stage 3 or 4 disease, Children's Oncology Group intermediate- or high-risk disease, and unfavorable histology at initial diagnosis. For the five patients with surgical correlation, pancreatic surgical specimens revealed neuroblastoma in three cases and ganglioneuroblastoma in two cases.

CONCLUSION

Although rare, pancreatic involvement in neuroblastoma occurs. Its variable imaging appearance should be considered when evaluating the retroperitoneum in patients with known or suspected neuroblastoma, particularly because increased patient survival holds the potential for uncommon patterns of recurrence.

Pediatric primary and metastatic neuroblastoma: MRI findings: pictorial review

Magnetic resonance imaging (MRI) has become one of the most valuable modalities for initial and follow-up imaging of suspected or known neuroblastoma (NBL) owing to its excellent inherent contrast, lack of ionizing radiation and multiplanar imaging capability. Importantly, NBL has a variable appearance on different imaging modalities, and this is particularly pertinent to MRI. MRI is a cornerstone for management of NBL, providing essential information at initial presentation regarding diagnosis, staging, resectability and relation to vital structures. It can also define the extent of residual disease after surgical resection or assess the efficacy of treatment. Follow-up MRI is frequently performed to ensure sustained complete remission or to monitor known residual disease. This pictorial review article aims to provide the reader with a concise, yet comprehensive, collection of MR images of primary and metastatic NBL lesions with relevant correlation with other imaging modalities.

Role of positron emission tomography-computed tomography in staging and early chemotherapy response evaluation in children with neuroblastoma

BACKGROUND

To evaluate the role of positron emission tomography-computed tomography (PET-CT) in staging and determining early treatment response to chemotherapy in children with neuroblastoma (NB) and its correlation with the final outcome.

PATIENTS AND METHODS

Seventeen patients of NB with mean age of 51.5 months (age range 2-132 months; 14 males, 3 females) underwent serial 18F-flourodeoxygl ucose (FDG) PET-CT imaging. All 17 patients were for staging before any treatment. Twelve of 17 patients underwent I-131 meta-iodobezylguanidine (MIBG) scan and bone scan. MIBG uptake was seen in the primary lesion in 11/12 patients. MIBG uptake in bones was seen in 3/12 patients. All bone lesions were concordant on MIBG and bone scan. Early response to chemotherapy was evaluated after two cycles using PET-CT. A 30% reduction in longest diameter was taken as cut-off value for response on CT based on the response evaluation criteria in solid tumors criteria. Response on PET-CT was assessed using percentage improvement in lesion to background SUV ratio, taking a value of 50% as cut-off. Final outcome based on follow-up ranging from 6 to 43 months (mean 18.8 months) served as reference.

RESULTS

All 17 patients showed increased FDG uptake at the primary site. Seven of the 17 patients (41.2%) showed metastasis. Lymph nodes were the most common site of metastatic disease followed by bone, bone marrow, lung and meninges. For response evaluation, change in the size of the primary tumor was noted in 11/17 (64.7%) patients on CT. Treatment response was noted in 12/17 patients (70.6%) on PET-CT. Eleven out of 17 (65%) patients showed response in both CT and PET-CT. Five out of 17 patients showed no response in both. Discordant findings on CT and PET were noted in one (5.9%) patient where PET showed response but no response was seen on CT. Two patients with initial response but with distant metastases expired during follow-up.

CONCLUSION

PET-CT has potential in the initial staging of NB. PET-CT also appears to be a good modality for response assessment in patients with moderate and high FDG uptake on the baseline scan. However, no significant beneficial effect was seen in patients with low baseline FDG uptake.

Lung-residing metastatic and dormant neuroblastoma cells

The mechanism by which dormant tumor cells can begin growing after long periods of inactivity and accelerate disease recurrence is poorly understood. The present study characterizes dormant neuroblastoma (NB) cells, as well as metastatic cells, which reside in the same organ microenvironment. A xenograft model of human NB consisting of variants that generate nonmetastatic local tumors in the orthotopic inoculation site and variants that generate lung metastatic NB (MetNB) cells was developed in our laboratory. The present study shows that lungs of mice inoculated with nonmetastatic NB variants contain disseminated neuroblastoma (DisNB) human cells. Both DisNB and MetNB variants expressed a similar tumorigenicty phenotype in vivo, whereas the MetNB variants produced a heavy metastatic load and the DisNB variants produced no or little metastasis. A comparative in vitro characterization of MetNB and DisNB cells revealed similarities and differences. DisNB, but not MetNB cells, expressed the minimal residual disease markers PHOX2B and TH. MetNB cells demonstrated higher migratory capacity, an elevated matrix metalloproteinase (MMP) secretion, and a higher constitutive phosphorylation of extracellular signal-regulated kinase (ERK) than DisNB cells. We suggest that characteristics common to both MetNB and DisNB cells were acquired relatively early in the metastatic process and the characteristics that differ between these variants were acquired later. We hypothesize that the DisNB cells are metastasis precursors, which may progress toward metastasis under certain microenvironmental conditions.

Neuroblastoma with primary pleural involvement: an unusual presentation

Neuroblastomas are the most common neoplasms in infants. We report a 10-month-old who was diagnosed with thoracic neuroblastoma, with imaging showing unusual primary extension into the pleura, which might have an adverse staging and prognostic significance.

Retroperitoneal neoplasms within the perirenal space in infants and children: differentiation of renal and non-renal origin in enhanced CT images

PURPOSE

To retrospectively demonstrate the specific CT findings of retroperitoneal neoplasms to diagnosis and differential diagnosis renal and non-renal tumors within the perirenal space in infants and children.

MATERIALS AND METHODS

We retrospectively reviewed the clinical data and CT images of 42 consecutive patients with surgically and pathologically proven retroperitoneal neoplasms within the perirenal space. The patients were divided into renal tumors group (n=16) and non-renal tumors group (n=26). The former included nephroblastoma (n=15) and renal lymphoma (n=1), while the latter included neuroblastoma (n=12), retroperitoneal teratoma (n=6), adrenal ganglioneuroma (n=4), retroperitoneal lymphoma (n=2), ectopic pheochromocytoma (n=1) and adrenal cortical carcinoma (n=1). The clinical information of these patients and the major CT imaging findings which were related to lesion localization in the two groups were compared and statistically analyzed using Pearson Chi-Square Test and Risk Estimate.

RESULTS

The mean diameter of tumors was 9.82±6.13 cm (n=42 range: 2.3-3 2cm). The demographic data and chief clinical symptoms between the renal tumor group and the non-renal tumor group showed no statistically significant differences (P>0.05). 30.8% (8/26) of non-renal tumor patients presented elevated urinary vanillylmandelic acid (VMA) level, while no patient showed elevated VMA in renal tumor group (P<0.05). Some CT imaging signs of the renal tumors including "crescent sign" (odds ratio, OR=52), "beak sign" (OR=84), "embedded organ sign" (OR=84), and "prominent feeding artery sign" (OR=36) showed significantly higher incidence when compared to the non-renal tumors (P<0.001). The sign of "renal displacement and renal axis rotation" (OR=0.059) was seen in 23 of 26 (88.5%) non-renal tumors, but in only 5 of 16 (31.3%) renal tumors (P<0.001). The sign of "extra-renal central plane of tumor" (OR=0.038) was displayed in 24 of 26 (92.3%) non-renal tumors, but in only 5 of 16 (31.3%) renal tumors (P<0.001). The CT findings such as "pseudocapsule" (OR=38.5), "necrosis and cystic change" (OR=11.2), "vascularity" (OR=16.867), "distant metastasis" (OR=5.96), and "inferior vena cava tumor thrombus" which were thought to be characteristic of renal tumors were observed with significant higher incidence in renal tumors group than in the non-renal tumors group (P<0.05); while CT signs of "irregular mass" (OR=0.045) and "intratumoral calcifications" (OR=0.065) were observed with lower incidence in renal tumors group than in the non-renal tumors group (P<0.05).

CONCLUSION

The "crescent sign", "beak sign", "embedded kidney sign" and "renal arteries feeding" are the most specific CT signs suggestive of renal tumors and distinguish them from non-renal origin tumors within the perirenal space. Other CT signs, such as "pseudocapsule", "hypervascular tumors" and "Inferior vena cava tumor thrombus", when present, tumors of renal origin are strongly suggested. On the other hand, CT signs of "irregular mass", "intratumoral calcifications", and associated elevated urinary vanillylmandelic acid strongly suggest the non-renal tumors.

Gene-expression-based analysis of local and metastatic neuroblastoma variants reveals a set of genes associated with tumor progression in neuroblastoma patients

Metastasis is the primary cause of mortality in Neuroblastoma (NB) patients, but the metastatic process in NB is poorly understood. Metastsis is a multistep process that requires the coordinated action of many genes. The identification of genes that promote or suppress tumor metastasis can advance our understanding of this process. In the present study, we utilized a human NB xenograft model comprising local and metastatic NB variants, which was recently developed in our laboratory. We set out to identify molecular correlates of NB metastasis and to determine the clinical relevance of these molecules. We first performed genome-wide expression profiles of metastatic and nonmetastatic NB variants that have an identical genetic background. We found that some of the proteins highly expressed in the metastatic NB variants are localized in the cytoplasm and endoplasmic reticulum. Other proteins are linked to metabolic processes and signaling pathways, thereby supporting the invasive and metastatic state of the cells. Subsequently, we intersected the differentially expressed genes in the human xenografted variants with genes differentially expressed in Stage 1 and Stage 4 primary tumors of NB patients. By using the same gene-expression platform, molecular correlates associated with metastatic progression in primary NB tumors were identified. The resulting smaller gene set was clinically relevant as it discriminated between high- and low-risk NB patients.

The International Neuroblastoma Risk Group (INRG) staging system: an INRG Task Force report

PURPOSE

The International Neuroblastoma Risk Group (INRG) classification system was developed to establish a consensus approach for pretreatment risk stratification. Because the International Neuroblastoma Staging System (INSS) is a postsurgical staging system, a new clinical staging system was required for the INRG pretreatment risk classification system.

METHODS

To stage patients before any treatment, the INRG Task Force, consisting of neuroblastoma experts from Australia/New Zealand, China, Europe, Japan, and North America, developed a new INRG staging system (INRGSS) based on clinical criteria and image-defined risk factors (IDRFs). To investigate the impact of IDRFs on outcome, survival analyses were performed on 661 European patients with INSS stages 1, 2, or 3 disease for whom IDRFs were known.

RESULTS

In the INGRSS, locoregional tumors are staged L1 or L2 based on the absence or presence of one or more of 20 IDRFs, respectively. Metastatic tumors are defined as stage M, except for stage MS, in which metastases are confined to the skin, liver, and/or bone marrow in children younger than 18 months of age. Within the 661-patient cohort, IDRFs were present (ie, stage L2) in 21% of patients with stage 1, 45% of patients with stage 2, and 94% of patients with stage 3 disease. Patients with INRGSS stage L2 disease had significantly lower 5-year event-free survival than those with INRGSS stage L1 disease (78% +/- 4% v 90% +/- 3%; P = .0010).

CONCLUSION

Use of the new staging (INRGSS) and risk classification (INRG) of neuroblastoma will greatly facilitate the comparison of risk-based clinical trials conducted in different regions of the world.

Lung metastases in neuroblastoma at initial diagnosis: A report from the International Neuroblastoma Risk Group (INRG) project

BACKGROUND

Neuroblastoma is the most common extracranial pediatric solid cancer. Lung metastasis is rarely detected in children with newly diagnosed neuroblastoma. We aimed to describe the incidence, clinical characteristics, and outcome of patients with lung metastasis at initial diagnosis using a large international database.

PROCEDURE

The subset of patients from the International Neuroblastoma Risk Group database with INSS stage 4 neuroblastoma and known data regarding lung metastasis at diagnosis was selected for analysis. Clinical and biological characteristics were compared between patients with and without lung metastasis. Survival for patients with and without lung metastasis was estimated by Kaplan-Meier methods. Cox proportional hazards methods were used to determine the independent prognostic value of lung metastasis at diagnosis.

RESULTS

Of the 2,808 patients with INSS stage 4 neuroblastoma diagnosed between 1990 and 2002, 100 patients (3.6%) were reported to have lung metastasis at diagnosis. Lung metastasis was more common among patients with MYCN amplified tumors, adrenal primary tumors, or elevated lactate dehydrogenase (LDH) levels (P < 0.02 in each case). Five-year overall survival +/- standard error for patients with lung metastasis was 34.5% +/- 6.8% compared to 44.7% +/- 1.3% for patients without lung metastasis (P = 0.0002). However, in multivariable analysis, the presence of lung metastasis was not independently predictive of outcome.

CONCLUSIONS

Lung metastasis at initial diagnosis of neuroblastoma is associated with MYCN amplification and elevated LDH levels. Although lung metastasis at diagnosis was not independently predictive of outcome in this analysis, it remains a useful prognostic marker of unfavorable outcome.

Generation and characterization of novel local and metastatic human neuroblastoma variants

Neuroblastoma (NB) is the most commonly occurring solid tumor in children. The disease usually arises in the adrenal medulla, and it is characterized by a remarkable heterogeneity in its progression. Most NB patients with an advanced disease have massive bone marrow infiltration at diagnosis. Lung metastasis represents a widely disseminated stage and is typically considered to be a terminal event. Much like other malignancies, NB progression is a complex, multistep process. The expression, function, and significance of the various factors involved in NB progression must be studied in relevant in vivo and in vitro models. Currently, models consisting of metastatic and nonmetastatic cell variants of the same genetic background exist for several types of cancer; however, none exists for NB. In the present study, we describe the generation of a NB metastasis model. SH-SY5Y and MHH-NB-11 NB cells were inoculated orthotopically into the adrenal glands of athymic nude mice. Neuroblastoma cells metastasizing to the lungs were isolated from mice bearing adrenal tumors. Lung metastatic variants were generated by repeated cycles of in vivo passage. Characterization of these variants included cellular morphology and immunophenotyping in vitro, aggressiveness in vivo, and various biologic parameters in vitro. The NB metastatic variant in each model displayed unique properties, and both metastatic variants demonstrated a metastatic phenotype in vivo. These reproducible models of human NB metastasis will serve as an unlimited source of transcriptomic and proteomic material. Such models can facilitate future studies on NB metastasis and the identification of novel NB biomarkers and targets for therapy.

Pediatric pulmonary tumors: primary and metastatic

Pediatric pulmonary tumors are rare. There is often a significant delay in diagnosis of pulmonary tumors secondary to their rarity and nonspecific presenting physiologic and radiographic findings. A high index of suspicion in pediatric patients with recurrent or persistent pulmonary symptoms is of paramount importance in diagnosing pulmonary tumors at an early stage. Malignant pulmonary tumors are more frequently diagnosed than benign lesions, with metastatic cancers being the most common. Complete surgical resection remains the basis of therapy for primary lesions, and its role in secondary cancers is becoming more established. Adjuvant therapies are frequently employed depending on the precise tumor involved. Mortality rates vary greatly depending on tumor location, stage, and type.

Significance of pleural effusion in neuroblastoma

BACKGROUND

Pleural effusion is uncommon at diagnosis of neuroblastoma in children. Because the presence of malignant cells in pleural fluid may significantly change the management and outcome of patients with neuroblastoma, we retrospectively analyzed a cohort of neuroblastoma patients who presented with pleural effusion at the time of diagnosis to determine the incidence, presentation, stage, treatment, and outcome of these patients.

METHODS

We reviewed the presenting features of 295 patients with the diagnosis of neuroblastoma who received treatment at St. Jude Children's Research Hospital between 1991 and 2005. Patients were chosen for further analysis if pleural effusion had been identified on chest radiographs or computed tomography (CT) scans at diagnosis

RESULTS

Thirty-one out of 295(10.5%) patients with neuroblastoma had pleural effusion identified at time of presentation. International neuroblastoma staging system (INSS) risk stratification was high risk in 29 cases and intermediate risk and low risk in 1 case each. The primary site of disease was abdomen in 26 patients; mediastinum in 5. We conducted cytologic analysis of pleural fluid of nine patients; the specimen of seven contained malignant cells. Eighteen of 31 patients died of progressive or recurrent disease.

CONCLUSION

In patients with neuroblastoma, pleural effusion is usually associated with unfavorable biologic features and high-risk disease. Pleural fluid should be examined cytologically and at a time when the results would change the risk stratification. There was no statistically significant difference in the survival rate of the patients with high-risk neuroblastoma with or without malignant pleural effusion.

Pulmonary metastasectomy in pediatric patients

This article describes the historical development of pediatric pulmonary metastasectomy but demonstrates that progress has been slow in understanding its proper applications. Because many pediatric metastatic tumors are rare, surgeons have grouped together patients of different histologies for the generation and analysis of case series. By examining tumor types individually, however, it is seen that certain histologies (adrenocortical carcinoma, alveolar soft part sarcoma, osteosarcoma) mandate surgical metastasectomy for patient survival. Other pediatric tumors (Wilms tumor, Ewing's sarcoma) are radiation sensitive, and the application of metastasectomy is controversial. In the case of still other types of tumor (neuroblastoma, differentiated thyroid cancer, rhabdomyosarcoma), metastasectomy is seldom performed except in highly unusual situations. Techniques for minimally invasive biopsy and for muscle-sparing thoracotomy are described for pediatric patients.

Neuroblastoma in adolescents

BACKGROUND

Neuroblastoma (NB) occurs rarely during adolescence, and information is scarce on its characteristics and clinical course in this age group.

METHODS

Patients with NB who were included in the Italian Neuroblastoma Registry were considered for the current study. The clinical characteristics and survival of adolescents (age at diagnosis between 10 yrs and 18 yrs) were compared with those of children (ages 1-9 yrs). Infants (age < 1 yr) were excluded because of their well known favorable clinical course.

RESULTS

Between 1116 children and 53 adolescents who were evaluated, no differences were documented with regard to the primary tumor site and the prevalence of advanced stage at diagnosis. If only patients with Stage IV NB were considered, then adolescents were less likely to be diagnosed with bone/bone marrow metastases (77%) compared with children (94%; P = 0.038), but adolescents were more likely to have metastases at unusual sites, such as the lung parenchyma or the central nervous system (23% vs. 7%, respectively; P = 0.005). With regard to biologic characteristics, adolescents did not differ significantly from children, although they always had a lower prevalence of unfavorable markers. In particular, MYCN amplification was documented in 21% of children and in 11% of adolescents (P = 0.173). At age 10 years, adolescents had a 20% overall survival rate and a 22% event-free survival rate. Adolescents who had resectable disease had a 73% overall survival rate, which was worse compared with the rate among children with the same disease stage (89%), although the difference did not reach statistical significance (P = 0.159). No differences in survival were observed among patients with Stage IV NB, and adolescents had a probability of survival almost identical to that among children (6% vs. 16%, respectively; P = 0.481). However, when the analysis was restricted to events that occurred after patients developed a recurrence, even if the final outcome was poor for both groups, the difference was statistically significant (P = 0.022) mostly because of the more indolent disease course observed among the adolescents. This effect was even more evident for patients with Stage IV NB. When the 6-year cut-off point was used to separate children from adolescents, a significantly worse overall survival rate (P = 0.036) was documented for adolescents who had resectable disease (81% vs. 93% in children).

CONCLUSIONS

NB in adolescents had clinical and biologic characteristics similar to those observed among children. The clinical course of NB probably is correlated significantly with age at diagnosis, but information is scarce on the role of the biologic risk factors in this age group. The authors were able to identify a group of patients with a cut-off age between 6 years and 10 years that had a more indolent course but a worse prognosis.

Imaging of neuroblastoma and Wilms' tumor

Neuroblastoma and Wilms' tumor are the most common noncentral nervous system solid tumors in children. Imaging plays a crucial role in the evaluation of the primary tumor and regional and metastatic disease. There is a growing body of literature supporting the use of MRI as the technique of choice for the evaluation of local and regional disease in children with suspected neuroblastoma; however, in children with suspected Wilms' tumor, MRI will likely continue to play a role as a problem-solver when the results of CT are equivocal or indeterminant.

Pulmonary metastases at diagnosis of neuroblastoma in pediatric patients: CT findings and prognosis

OBJECTIVE

We undertook this study to determine the frequency, CT appearance, and clinical implications of the rare occurrence of pulmonary metastases among children presenting with neuroblastoma.

MATERIALS AND METHODS

A search of the Children's Cancer Group database revealed 21 of 567 children with reported lung metastases at original diagnosis of neuroblastoma. CT examinations available for 17 of these patients were analyzed retrospectively to determine if lung metastases were present, and if so, to characterize their radiographic features.

RESULTS

Seventeen (3%) of 567 patients presenting with Evans stage IV neuroblastoma had confirmed pulmonary metastases at diagnosis. All had metastases to at least one site other than the lungs. The most common CT appearance of pulmonary lesions was of up to five, small, bilateral, noncalcified nodules. In nine patients (53%), the pulmonary nodules initially resolved with treatment. In this cohort, six children developed progressive disease and died, and three are still alive. All eight children whose lung lesion did not completely respond to treatment died. Overall, children with pulmonary metastases had unfavorable Shimada histology, a higher association with amplification of the MYCN oncogene (p = 0.0002), and a decreased event-free survival (p < 0.001) when compared with all children with stage IV neuroblastoma without pulmonary metastases.

CONCLUSION

The search for neuroblastoma lung metastases, which occur more frequently than previously reported, is clinically important because their presence portends a poor prognosis.

Metastatic sites in stage IV and IVS neuroblastoma correlate with age, tumor biology, and survival

PURPOSE

The goal of this study was to determine the incidence of metastatic sites in neuroblastoma and the extent to which metastatic sites correlate with age, tumor biology, and survival.

PATIENTS AND METHODS

All 648 patients with stage IV and IVS neuroblastoma registered on Children's Cancer Group protocols 3881 and 3891 were analyzed. Metastatic site data were provided by treating institutions and reviewed in patients with central nervous system (CNS), intracranial, lung, or "other" metastases.

RESULTS

The incidence of metastatic sites at diagnosis was 70.5% in bone marrow, 55.7% in bone, 30.9% in lymph nodes, 29.6% in liver, 18.2% in intracranial and orbital sites, 3.3% in lung, and 0.6% in CNS. Event-free survival (EFS) was decreased in patients with bone, bone marrow, CNS, intracranial/ orbital, lung, and pleural metastases, and improved in those with liver and skin metastases. In infants, MYCN amplification and unfavorable Shimada histopathology correlated with increased frequencies of bone and intracranial or orbital metastases. In older patients, MYCN amplification correlated with increased frequencies of intracranial or orbital, liver, and lung metastases. Multivariate analysis revealed that metastatic site is not an independent prognostic factor.

CONCLUSIONS

Metastatic pattern in neuroblastoma differs with age and correlates with tumor biological features and EFS. These correlations could reflect changes in host or tumor biological features with age resulting in differences in metastatic capacity or tumor affinity for specific sites.