Peripheral neuroblastic tumors: pathologic classification based on recommendations of international neuroblastoma pathology committee (Modification of shimada classification)

Retroperitoneal ganglioneuroma in an adult patient: a case report and literature review of the last decade

Ganglioneuromas arise from the neural crest and are highly differentiated and benign. The case of a 43-year-old female who presented with a 6.5 cm primary extra-adrenal retroperitoneal ganglioneuroma (RGN) is presented, and the relevant English literature from the last decade is reviewed. Histology showed mature ganglion cells and nerve fibers without any malignancy (S-100 and neuron- specific enolase [NSE] positive). Hospitalization lasted four days. The patient has shown no signs of recurrence. Radical excision of the tumor is unnecessary, especially when vascular structures are endangered. RGN-related hospitalization is short and the prognosis is good.

Composite paraganglioma-ganglioneuroma in the retroperitoneum

Background

Paragangliomas occur most commonly in head and neck region and much less frequently, they are found in the retroperitoneum. Composite paraganglioma-ganglioneuroma of the retroperitoneum is very rare.

Case presentation

We present an unusual case of retroperitoneal composite paraganglioma-ganglioneuroma discovered on computed tomography in a 63-year-old female patient. Routine hematological examination and biochemical tests were within normal limits. Plasma adrenaline was 0.042 ng/ml, plasma noradrenaline 0.341 ng/ml, and plasma dopamine <0.01 ng/ml. An abdominal contrast-enhanced CT scan and magnetic resonance imaging revealed a 6.5 cm heterogeneous retroperitoneal mass with a cystic component. The retroperitoneal tumor accumulated ¹³¹I-Metaiodobenzylguanidine (¹³¹I-MIBG) 48 hours after radioisotope injection. Under the diagnosis of paraganglioma in the retroperitoneum, the patient underwent surgery. The resected tumor (6.5 × 5 × 3 cm) was solid and easily removed en bloc. The cut surface of the tumor and histology revealed two different components in the tumor: paraganglioma centrally and ganglioneuroma on the periphery. She remains disease-free 18 months after surgery.

Conclusion

This case reminds us that neuroendocrine tumor should be included in the differential diagnosis of a retroperitoneal mass although composite paraganglioma-ganglioneuroma in the retroperitoneum is very rare.

MSX1 induces the Wnt pathway antagonist genes DKK1, DKK2, DKK3, and SFRP1 in neuroblastoma cells, but does not block Wnt3 and Wnt5A signalling to DVL3

Neuroblastoma is the most common extra-cranial solid childhood cancer; it arises from neural crest-derived cells of the sympathetic nervous system. The anomalous regulation of embryonic developmental pathways like Delta-Notch and Wnt has been implicated in aberrant cell growth and differentiation in many (childhood) tumours. We have previously found regulation of Delta-Notch pathway genes by the MSX1 neural crest development gene in a neuroblastoma cell line, and significant correlations between these genes in neuroblastic tumours. However, a clear role for the Wnt pathway in neuroblastic tumours has not yet been determined. We now analyze the complete spectrum of genes regulated by inducible expression of MSX1 in the SJNB8 neuroblastoma cell line using Affymetrix expression profiling. We show that MSX1 induces the expression of four different Wnt pathway inhibitor genes: Dickkopf 1-3 (DKK1-3) and secreted frizzled-related protein 1 (SFRP1), and provide evidence that high expression of two of these genes correlates with good prognosis. We were able to demonstrate that both the canonical Wnt3 and the alternative Wnt5A ligands are highly expressed in neuroblastic tumours and cell lines, and specifically activate the DVL3 Wnt co-receptor protein in SJNB8 neuroblastoma cells. These results suggest involvement of MSX1 in Wnt signalling and demonstrate activity of the more upstream Wnt pathway in neuroblastic cells.

Detection of isolated tumor cells in neuroblastoma by immunohistochemical analysis in bone marrow biopsy specimens: improved detection with use of beta-catenin

Evaluation of the bone marrow is a critical component of accurate staging and surveillance for recurrent disease in neuroblastoma. The value of routine immunohistochemical analysis of otherwise histologically negative bone marrow biopsy specimens has not been adequately evaluated. By using synaptophysin, chromogranin, and beta-catenin, immunohistochemical analysis performed on otherwise histologically negative bone marrow specimens identified isolated tumor cells (ITCs) in 9.1%, 5.0%, and 10.0% of 220 biopsy specimens, respectively. Overall survival, as estimated by the Kaplan-Meier method, was not significantly different between patients with and without ITCs (P = .357). Of the immunohistochemical markers evaluated, beta-catenin showed the greatest sensitivity for identifying ITCs in the bone marrow and showed reactivity in primary tumor samples. We found that the presence of ITCs identified by immunohistochemical analysis may predict the persistence of disease but does not show significant overall survival differences. We also identified beta-catenin as a sensitive immunohistochemical marker of primary and metastatic neuroblastoma.

[Verner-Morrison syndrome revealing a ganglioneuroblastoma in an adult]

Most vasoactive intestinal peptide (VIP)-producing tumours are from epithelial origin. Tumours derived from the sympathetic nervous system can produce VIP as well. We report here the case of a Verner-Morrison syndrome in a 40-year-old woman revealing a metastatic ganglioneuroblastoma. The diarrhea resolved after the resection of primary tumour and liver metastases. Neuroblastic tumours occur extremely rarely in adults. Thus, the management of these tumours is poorly defined in adults.

A 5-year-old girl with a congenital ganglioneuroma diagnosed by fine needle aspiration biopsy: a case report

Introduction

Ganglioneuroma is a rare, benign, neuroblastic tumor arising mainly from the central or peripheral autonomic nervous system, especially the sympathetic system. The most affected anatomical sites are the posterior mediastinum, retroperitoneum, adrenal gland and head and neck soft tissue. In the current literature, reports of ganglioneuroma diagnosed by fine-needle aspiration and its cytological appearance are scarce.

Case Presentation

A 5-year-old girl presented with a mass in the cervical region since birth. Laboratory routine tests were within normal limits, ultrasonography demonstrated a solid and well-circumscribed lesion in the soft tissues of the cervical region. Fine needle aspiration biopsy was carried out, and the obtained smears showed a mixture of mature ganglion cells and groups of spindle cells suggestive of schwann cell origin. A diagnosis of ganglioneuroma was suggested. Core biopsy and surgical resection confirmed this diagnosis.

Conclusion

Congenital ganglioneuroma of the cervical region is an uncommon soft tissue benign neoplasm of neuroblastic origin, and it should be considered in the differential diagnosis of head and neck pediatric soft tissue tumors. Fine needle aspiration biopsy technique is a reliable method that can be used with confidence when dealing with pediatric soft tissue tumors.

The MSX1 homeobox transcription factor is a downstream target of PHOX2B and activates the Delta-Notch pathway in neuroblastoma

Neuroblastoma is an embryonal tumour of the peripheral sympathetic nervous system (SNS). One of the master regulator genes for peripheral SNS differentiation, the homeobox transcription factor PHOX2B, is mutated in familiar and sporadic neuroblastomas. Here we report that inducible expression of PHOX2B in the neuroblastoma cell line SJNB-8 down-regulates MSX1, a homeobox gene important for embryonic neural crest development. Inducible expression of MSX1 in SJNB-8 caused inhibition of both cell proliferation and colony formation in soft agar. Affymetrix micro-array and Northern blot analysis demonstrated that MSX1 strongly up-regulated the Delta-Notch pathway genes DLK1, NOTCH3, and HEY1. In addition, the proneural gene NEUROD1 was down-regulated. Western blot analysis showed that MSX1 induction caused cleavage of the NOTCH3 protein to its activated form, further confirming activation of the Delta-Notch pathway. These experiments describe for the first time regulation of the Delta-Notch pathway by MSX1, and connect these genes to the PHOX2B oncogene, indicative of a role in neuroblastoma biology. Affymetrix micro-array analysis of a neuroblastic tumour series consisting of neuroblastomas and the more benign ganglioneuromas showed that MSX1, NOTCH3 and HEY1 are more highly expressed in ganglioneuromas. This suggests a block in differentiation of these tumours at distinct developmental stages or lineages.

Morphometric evaluation of NB84, synaptophysin and AgNOR is useful for the histological diagnosis and prognosis in peripheral neuroblastic tumors (pNTs)

OBJECTIVE

To study the importance of NB84, synaptophysin and AgNOR and explore the quantitative association of these factors with diagnosis and outcome as well as the association between NB84 and AgNOR and other tumor and stromal factors in twenty-eight peripheral neuroblastic tumors.

METHODS

We assessed AgNORs, NB84, synaptophysin and several other markers in tumor tissues from 28 patients with primary neuroblastic tumors. The treatment included: surgery for stage 1, chemotherapy and bone marrow transplantation for most of stages 3 and 4. Histochemistry, immunohistochemistry and morphometry were used to evaluate the amount of tumor staining for AgNOR, NB84 and synaptophysin; the outcome for our study was survival time until death due to recurrent neuroblastic tumors.

RESULTS

Only stage (p<0.01), AgNOR (p<0.01), NB84 (p<0.01) and synaptophysin (p=0.01) reached statistical significance as prognostic indicators.

CONCLUSIONS

Determination of NB84 and synaptophysin are useful tools for the diagnosis of peripheral neuroblastic tumors The association of the evaluation of AgNOR expression by the tumor cells may provide an important contribution to the prognostic evaluation and management approach of the patients.

Concomitant DDX1 and MYCN gain in neuroblastoma

DDX1, a gene mapping to the 2p24 region, has been observed to be co-amplified with MYCN in neuroblastoma. Co-amplification of the DDX1 gene is a consequence of the short physical distance between the two genes. Recently, it has been found that neuroblastoma cells can show a low increase in MYCN gene copy number, defined as MYCN gain. We studied 13 neuroblastomas with MYCN gain to evaluate the status of the DDX1 gene. We investigated DDX1/MYCN gain by double-colour FISH on interphase nuclei. All cases showed concomitant low extra copy number of DDX1 and MYCN. Heterogeneous distribution of nuclei displaying DDX1/MYCN gain was observed in almost all tumours, suggesting a clonal evolution of cells with DDX1/MYCN gain. This is the first report that shows DDX1 co-gained with MYCN in neuroblastoma and indicates that DDX1 over-representation is closely associated with an increase in MYCN copy number in neuroblastoma cells. Since DDX1 has already been found co-amplified with MYCN, DDX1 gain seems to be a further rearrangement due to the physical proximity of the two genes. Moreover, all patients with DDX1/MYCN gain show a good overall survival but a high frequency of adverse events.

Diagnostic and prognostic impact of urinary catecholamines in neuroblastoma patients

BACKGROUND

Urinary catecholamine metabolites are well-known to be elevated in patients with neuroblastoma. Some investigators have described different patterns in favorable and unfavorable cases. However, extended studies have not been published.

PROCEDURE

We investigated urinary catecholamine patterns and their correlation to stage, biological features, and outcome in 114 consecutively clinically diagnosed neuroblastoma patients.

RESULTS

Sensitivity of vanillylmandelic acid (VMA), homovanillic acid (HVA), and dopamine (DA) was 80.7, 71.9, and 61.3%, respectively. In 91.2% of patients at least one parameter was above normal. High VMA levels were associated with favorable biological features, high DA levels were predominantly found in biologically unfavorable disease. Whereas patients with normal HVA levels had a significant better outcome, the other parameters showed no significant association with prognosis. For disseminated neuroblastoma of infancy, DA/VMA ratio proved to be helpful for the discrimination of stage 4 versus stage 4s.

CONCLUSION

Urinary catecholamines appear to be useful to give a first but important hint about the biological behavior and thus the prognosis of the underlying disease. Particularly DA/VMA ratio may serve as a tool for "biological grading"-especially in disseminated disease of infancy. In addition, it may be speculated that HVA negativity and low DA/VMA ratio may be helpful for the decision of a "wait and see" strategy in selected neuroblastoma patients with localized disease.

Presacral ganglioneuroma: A case report and review of literature

Presacral ganglioneuromas are so rare benign tumors that only 17 cases have been reported in the literature. They are abdominal masses growing slowly and differential diagnoses have to be considered. Surgical resection is important for definitive diagnosis because it represents the only therapeutic choice. Because of the benign nature of ganglioneuroma, adjuvant chemo- or radiotherapy is not indicated but regular follow-up is necessary for an early diagnosis of potential local recurrence. We report a case of a 64-year-old man with a presacral ganglioneuroma.

Tubedown Expression Correlates with the Differentiation Status and Aggressiveness of Neuroblastic Tumors

PURPOSE

The discovery and validation of new prognostic factors and further refinement of risk group stratification are needed to improve clinical interpretation of neuroblastoma. Our laboratory isolated and characterized a developmentally regulated gene named TUBEDOWN against which we have raised a monoclonal antibody (OE5). Tubedown becomes down-regulated postnatally yet remains strongly expressed in some neuroblastomas. The purpose of this study is to define the utility of Tubedown expression as a new measure of the differentiation status and aggressiveness of neuroblastic tumors.

EXPERIMENTAL DESIGN

Tubedown protein expression was quantitatively assessed in neuroblastic tumors (neuroblastomas, ganglioneuroblastomas, and ganglioneuromas) and normal adrenal tissues using Western blot and OE5 immunohistochemistry. Regulation of Tubedown expression during retinoic acid-induced neuronal differentiation in neuroblastoma cell lines was assessed by Western blotting.

RESULTS

High levels of Tubedown expression are observed in tumors with significant neuroblastic component, unfavorable histopathology, advanced stage, high-risk group, and poor outcome. In contrast, more differentiated subsets of neuroblastic tumors, ganglioneuroblastomas with favorable histopathology and ganglioneuromas, express low levels of Tubedown. In vitro, marked retinoic acid-induced neuronal differentiation responses of neuroblastoma cells are associated with a significant decrease in Tubedown expression, whereas limited neuronal differentiation responses to retinoic acid were associated with little or no decrease in Tubedown expression.

CONCLUSIONS

Our results indicate that the levels of Tubedown expression are linked to the differentiation status and aggressiveness of neuroblastic tumors and represent an independent prognostic factor for neuroblastoma. Tubedown expression may be useful to more accurately define different neuroblastic tumor subsets and ultimately provide more adequate assessment and treatment for neuroblastoma patients.

Correlation of modified Shimada classification with MYCN and 1p36 status detected by fluorescence in situ hybridization in neuroblastoma

Neuroblastoma (NB) is a childhood cancer derived from neural crest cells, with a highly variable clinical course and biologic behavior. NB cells harbor complex genetic changes. Also, MYCN amplification is a well-known molecular marker for aggressive progression, and deletion of the short arm of chromosome 1 is frequently observed in NB. The aim of this study was to investigate the correlation between genetic markers and prognostic morphological parameters to address the biology and underlying the clinical complexity of NB. Therefore, we performed fluorescence in situ hybridization analyses of chromosome band 1p36 and MYCN in a series of tumors from 43 cases classified according to the recommendation of International Neuroblastoma Pathology Committee (modification of Shimada classification). The correlations of MYCN amplification status and two distinct types of 1p36 alterations (deletion and imbalance) with Shimada classification and histologic prognostic factors were statistically analyzed. Amplification of MYCN and 1p36 deletion was present in 14 (32.6%) and 18 (41.9%) cases, respectively. Sixteen cases (37.2%) displayed a favorable histology, while 27 (62.8%) had an unfavorable histology. The 1p36 deletion was found to be an independent predictor of unfavorable histology by multivariate analysis (logistic regression test, P = 0.03), but the 1p36 imbalance did not show any significance. Both 1p36 deletion and MYCN amplification showed significant correlation with undifferentiated tumors (chi-square test, P = 0.002 and 0.03, respectively). Highly significant correlation was found between the higher mitotic karyorrhectic index (MKI) and MYCN amplification (chi-square test, P < 0.001), whereas neither 1p36 deletion nor 1p36 imbalance significantly correlated with a higher MKI (chi-square test, P > 0.05). We conclude that 1p36 deletion may be a reliable parameter in determining unfavorable histology and predicting prognosis in NB. Further studies with prognostic data are needed to highlight its clinical significance.

Peripheral neuroblastic tumours in eastern Denmark 1972?2002

The peripheral neuroblastic tumour group includes neuroblastoma, ganglioneuroblastoma and ganglioneuroma. Neuroblastoma is the most common extracranial solid tumour of childhood. We have evaluated the histological presentation, MYCN gene status, and clinical course of peripheral neuroblastic tumours diagnosed and treated in eastern Denmark from 1972-2002. 125 patients were diagnosed with peripheral neuroblastic tumour during this 30-year period. The histological material was reviewed and classified into three categories in accordance with the Shimada system: unfavourable histology, favourable histology, and benign tumours. MYCN status was determined by fluorescent in situ hybridization (FISH) on paraffin sections from the primary tumour. Clinical information was obtained from hospital records. Diagnostic likelihood ratios in the two groups were calculated to compare the ability of MYCN status and histological classification to predict 5-year outcome. 41 tumours showed unfavourable histology, 30 tumours showed favourable histology, 11 were benign, and 43 were unclassifiable due to limited amounts of primary tumour, bad preservation or inaccessibility of the primary tumour necessitating metastatic tumour biopsy for diagnosis. Unfavourable histology was associated with widespread disease (p<0.001). The overall 5-year survival rate was 45%, which correlates well with the European survival rate reported for this time period. The 5-year survival rate in the unfavourable group was 30% as compared to 100% in the favourable histology group (p<0.001). The survival rate in the unclassifiable group was 13%. 26% of the neuroblastomas were MYCN amplified. MYCN amplification was associated with undifferentiated histology, a histological subtype of the unfavourable histology group (p<0.001). For unfavourable histology the positive diagnostic likelihood ratio was 2.9 as compared to 4.7 for MYCN amplification. The study has confirmed the prognostic significance of the Shimada system in the peripheral neuroblastic tumour group in a retrospective material, and has also demonstrated the prognostic superiority of MYCN compared to histological classification, thus reducing the necessary amounts of tumour tissue.

Pediatric presacral masses

Various types of masses may affect the presacral area in children. A presacral mass may be congenital or developmental or may arise from inflammation. The mass may have neural, vascular, lymphatic, or mesenchymal origins and may be primary (as in focal disease) or systemic (as in multifocal disease). Because the clinical manifestations of presacral masses are often nonspecific, imaging plays an important role in the detection and differentiation of these masses. Information obtained from imaging is also critical for management, especially for surgical planning. For these reasons, it is important that radiologists be familiar with the anatomy of the presacral region and with the imaging features of the various lesions that may occur in this region in children. For the accurate interpretation of findings, radiologists also must know the specific advantages and limitations of each of the imaging modalities used to evaluate this category of abnormalities.

Prognostic value of the International Neuroblastoma Pathology Classification in Neuroblastoma (Schwannian stroma-poor) and comparison with other prognostic factors: a study of 182 cases from the Spanish Neuroblastoma Registry

In addition to clinical and biological factors, further valuable prognostic information in neuroblastoma (Schwannian stroma-poor) (NB) patients is provided by the histopathologic analysis and the application of the International Neuroblastoma Pathology Classification (INPC) system. The objective of this study was to assess the prognostic impact of the INPC classification in a series of NB (Schwannian stroma-poor) and its relation with other prognostic factors. One hundred eighty-two cases of NB were collected from the files of the Spanish Neuroblastoma Registry. Slides were reviewed, and NB cases were grouped into favorable and unfavorable categories according to INPC criteria, taking into account morphological features (mitosis-karyorrhexis index, histological subtype) and patient's age at diagnosis. Other pathological [presence of calcifications, tissular components, and number of mitotic cells per 10 high-power field (HPF)], immunohistochemical (P-glycoprotein and Ki-67 protein expression) and genetic (MYCN amplification and chromosome 1p deletion) features were also studied. Statistical analyses of overall survival with Kaplan-Meier curves and a multivariate study using Cox regression were performed (40.3% of NBs were considered favorable and 59.7% unfavorable). Unfavorable NB showed a mean survival time of 57 months compared with 89 months in favorable cases. Advanced stage, more than ten mitoses per 10 HPF, Ki-67 expression in more than 30% of tumor cells, MYCN oncogene amplification and chromosome 1p deletion were observed more frequently in unfavorable NB. The Cox regression analysis demonstrated that clinical stage (International Neuroblastoma Staging System stage 4) and histological subtype (undifferentiated NB) were the most important factors that influence the overall survival (p<0.001). INPC classification results are major prognostic indicators in NB and should be considered in the therapeutic stratification of NB patients.

Presacral ganglioneuromas. Report of five cases and review of the literature

Ganglioneuromas are rare, benign, slow-growing tumors belonging to the neuroblastoma group. The authors describe the presentation and treatment of five consecutive patients who presented with presacral ganglioneuromas; these cases represent the largest series to date. A review of the literature is also performed.

Evolution of unbalanced gain of distal chromosome 2p in neuroblastoma

Neuroblastoma, one of the most common tumors of childhood, presents at diagnosis with a vast number of recurrent chromosomal imbalances that include hyperdiploidy for whole chromosomes, partial loss of 1p, 3p, 4p, 11q, 14q, partial gain of 1q, 7q, 17q and amplification of MYCN. These abnormalities are nonrandomly distributed in neuroblastoma as loss of 3p and 11q rarely occur in MYCN amplified neuroblastomas. Here, we report on a patient who had a non-MYCN amplified 3p-/11q- neuroblastoma at diagnosis who subsequently developed a high level of MYCN amplification in bone marrow metastases 41 months after induction of complete remission. The tumor at diagnosis had low level unbalanced gain of distal 2p. In order to assess the frequency of low level gain of distal 2p in neuroblastoma, we examined the comparative genomic hybridization results from 60 neuroblastomas. Among non-MYCN amplified neuroblastomas, 8/45 (18%) had low level gain of distal 2p. Low level gain for a segment of 2p (i.e. a region larger than the 2p23-->p24 undergoing amplification) was also detected in five of the 15 tumors that had high level MYCN amplification. The possibility that low level gain of distal 2p is a risk factor for high level MYCN amplification is discussed.

Familial neuroblastoma - different histological manifestations in a family with three affected individuals. Case history and review of the literature

Neuroblastoma is one of the most common malignant neoplasms in childhood. These tumours represent a heterogeneous group both in terms of clinical course and histological appearance, ranging from benign, slowly growing, often asymptomatic ganglioneuromas to malignant, highly aggressive neuroblastomas. Most cases occur sporadically, but in rare cases several individuals in the same family present with ganglioneuroblastomatous tumours. We report a case of familial neuroblastoma, occurring in a mother and her two daughters, with very different clinical presentation, outcome and tumour histology. The mother had recurrent, fully mature, benign ganglioneuromas, predominantly located in the retroperitoneum. The two daughters both developed malignant abdominal neuroblastomas, at the age of 2 and 8 years, respectively. Both died in spite of intensive therapy. Hereditary neuroblastoma appears to be as heterogeneous as the sporadic form of the disease. Since no consistent predisposition gene has been located in affected families, several different genetic or epigenetic events may account for the different histological and clinical presentations.

Revision of the International Neuroblastoma Pathology Classification: confirmation of favorable and unfavorable prognostic subsets in ganglioneuroblastoma, nodular

BACKGROUND

Ganglioneuroblastoma, nodular (GNBn) comprises one of the categories of peripheral neuroblastic tumors. All tumors in this category, according to the original International Neuroblastoma Pathology Classification, are classified into an unfavorable histology group. Subsequently, it has been reported that GNBn can be divided into two prognostic subsets, a favorable subset (FS) and an unfavorable subset (US).

METHODS

Histology slides from 70 patients who were enrolled in Children's Cancer Group studies 3881 and 3891 and who had a diagnosis of GNBn were reviewed jointly by the members of International Neuroblastoma Pathology Committee (INPC): 1) to confirm the diagnosis of GNBn, 2) to identify the FS and US by applying the same age-linked criteria that were used to distinguish the favorable histology group and unfavorable histology group in conventional neuroblastoma tumors from the neuroblastomatous component of GNBn tumors, and 3) to verify the significant prognostic difference between these two subsets. The patients had been used in a previous study, and survival data for the patients were updated since the time of their last report.

RESULTS

The review clarified and illustrated morphologic characteristics of classical GNBn and it variants. The diagnosis of GNBn was confirmed in 67 of 70 patients. There were 22 patients with GNBn in the FS and 45 patients with GNBn in the US. The estimated survival differences between the FS and US patients with GNBn were statistically significant (8-year event free survival rate: 86.1% vs. 32.2%; P = 0.0003; overall survival rate: 90.5% vs. 33.2%; P = 0.0003).

CONCLUSIONS

This study confirmed the recently defined prognostic subsets of GNBn. The INPC proposes to modify the International Neuroblastoma Pathology Classification by distinguishing the FS and the US among patients with GNBn tumors.

Are gains of chromosomal regions 7q and 11p important abnormalities in neuroblastoma?

Neuroblastoma exhibiting deletion of a segment of the long arm of chromosome 11 represents a genetic subtype of tumor that is distinct from those exhibiting MYCN amplification or 1p deletion. The 11q- genetic subtype is further characterized by gain of 17q and loss of distal 3p material. Gain of 11p material has also been reported in neuroblastoma with 11q loss, but at a considerably lower frequency than gain of 17q or loss of the distal 3p region. Our results, however, indicate that gain of 11p may occur more frequently in 11q- neuroblastoma than what was previously realized. Comparative genomic hybridization analyses of neuroblastoma tissue from eleven patients indicated that six of 11 tumors (55%) with loss of 11q also possessed gain of 11p. The shortest region of 11p gain was 11p11.2-->p14. G-banding and fluorescence in situ hybridization analysis performed on tumor cells from primary and metastatic sites from one patient allowed us to infer that gain of 11p arose secondarily to the abnormality that led to the loss of 11q material. Gain of an entire chromosome 7 was detected in 17 of 43 (40%) tumors, whereas gain of 7q was detected in 5 of 43 (12%) tumors. Unlike gain of 11p, gain of an entire chromosome 7 appears to be prevalent in all tumor stages and is not limited to the 11q- tumor subtype. Gain of 7q, however, is more prevalent in higher stage tumors. G-band cytogenetic analysis indicated that an unbalanced t(3;7) was responsible for the gain of 7q and loss of 3p material in one case. We discuss the possibility that gain of 7/7q, and 11p material may contribute to either tumorigenesis or progression.

Neuroblastoma, ganglioneuroblastoma, and ganglioneuroma: radiologic-pathologic correlation

Neuroblastoma, ganglioneuroblastoma, and ganglioneuroma are tumors of the sympathetic nervous system that arise from primitive sympathogonia and are referred to collectively as neuroblastic tumors. They arise wherever sympathetic tissue exists and may be seen in the neck, posterior mediastinum, adrenal gland, retroperitoneum, and pelvis. The three tumors differ in their degree of cellular and extracellular maturation; immature tumors tend to be aggressive and occur in younger patients (median age, just under 2 years), whereas mature tumors occur in older children (median age, approximately 7 years) and tend to behave in a benign fashion. The most benign tumor is the ganglioneuroma, which is composed of gangliocytes and mature stroma. Ganglioneuroblastoma is composed of both mature gangliocytes and immature neuroblasts and has intermediate malignant potential. Neuroblastoma is the most immature, undifferentiated, and malignant tumor of the three. Neuroblastoma, however, may have a relatively benign course, even when metastatic. Thus, these neuroblastic tumors vary widely in their biologic behavior. Features such as DNA content, tumor proto-oncogenes, and catecholamine synthesis influence prognosis, and their presence or absence aids in categorizing patients as high, intermediate, or low risk. Treatment consists of surgery and, usually, chemotherapy. Despite recent advances in treatment, including bone marrow transplantation, neuroblastoma remains a relatively lethal tumor, accounting for 10% of pediatric cancers but 15% of cancer deaths in children.

Regulation of telomerase activity by alternate splicing of human telomerase reverse transcriptase mRNA in a subset of neuroblastomas

It has been proposed that the regulation of telomerase takes place at the transcriptional level, the expression of the catalytic subunit human telomerase reverse transcriptase (hTERT) being crucial for telomerase activity (TA). Recently, differential splicing of hTERT mRNA has been demonstrated in various tissues during embryonal development, and it has been suggested that only full-length transcripts translate into functionally active telomerase. With this in view, we analyzed the different hTERT transcripts by reverse transcriptase-polymerase chain reaction in neuroblastic tumors and compared the results with the TA, the tumor growth fraction, and the MYCN status. In a series of 38 neuroblastic tumors, high TA and full-length hTERT transcripts were found in nine samples, whereas nine samples showed absence of both enzymatic activity and hTERT transcripts. Interestingly, in another eight samples, low or absent TA coincided with a lack of full-length hTERT transcripts. Eleven samples contained hTERT transcripts with low or undetectable TA and one sample had low TA but no hTERT transcripts. TA correlated with MYCN amplification and was weakly associated with the proliferative activity. Moreover, a significant correlation with tumor progression was observed. Our findings point at a posttranscriptional regulation of TA in a subset of neuroblastic tumors. Because high TA was detected only in tumors with full-length hTERT transcripts, reverse transcriptase-polymerase chain reaction analysis of archival neuroblastic tumor samples might help to appraise the malignant potential in individual cases.