Ewing sarcoma of the small intestine

This report describes a rare case of Ewing sarcoma (ES) of the small intestine. The patient was a 9-year-old girl with progressive abdominal distension. Computed tomography showed a large mass in the small bowel. Histopathologic examination of the resected tumor showed ES with typical histologic, immunohistochemical, and ultrastructural features. The tumor recurred in the pelvic cavity 18 months after the original surgery. Molecular study of the recurrent tumor confirmed a diagnostic EWS-FLI1 gene fusion. This patient illustrates the unique occurrence of ES in the small intestine.     

Concomitant p53 mutation and MYCN amplification in neuroblastoma

The MYCN oncogene is amplified in 20% of childhood neuroblastoma and is associated independently with poor prognosis. Alteration of the p53 tumor supressor gene, in contrast, occurs infrequently in these tumors. In this report, we described a 3-year-old girl with stage IV neuroblastoma. Molecular analysis revealed both MYCN gene amplification and a point mutation of the p53 tumor supressor gene. To our knowledge, this is the first reported case of neuroblastoma with genetic alterations of both these genes. Med. Pediatr. Oncol. 29:206–207, 1997. © 1997 Wiley-Liss, Inc.     

A neuroblastoma-selective suicide gene therapy approach using the tyrosine hydroxylase promoter

In this study, selective expression of therapeutic transgenes was evaluated in neuroblastoma cells. Promoter fragments of the genes for neuron-specific enolase (NSEp), tyrosine hydroxylase (THp), and dopamine-beta-hydroxylase (DBHp) were studied in neuroblastoma and nonneuronal cell lines by transient transfection experiments using fluorescence-activated cell sorting (FACS) analysis of enhanced green fluorescent protein (egfp) and luciferase (luc+) assay. Both reporter gene assays revealed a neuroblastoma-selective expression mediated by NSEp and THp, whereas DBHp was active only in a murine neuroblastoma cell line. Reporter gene expression by NSEp in neuroblastoma cells was markedly higher than expression by THp, but NSEp also showed considerable background activity in nonneuronal cells. THp-driven expression of egfp was 35-fold higher in human neuroblastoma MHH-NB11 compared with nonneuronal HeLa cells. Thus, THp was chosen for a neuroblastoma-selective suicide gene therapy approach using the herpes simplex virus type 1 thymidine kinase (HSV-tk)/ganciclovir (GCV) system. A retrovirus vector that contained an expression cassette of a HSV-tk/egfp fusion gene and THp in antisense orientation was generated. Stably transduced human neuroblastoma cells and nonneuronal cell lines were generated, and HSV-tk/egfp expression was measured by FACS and GCV cytotoxicity assay. There was a 2.2-fold difference in green fluorescence and a 1.4-fold difference in cell killing between the human neuroblastoma MHH-NB11 and HeLa cells after HSV-tk/egfp gene transfer. The overall difference in THp-HSV-tk/egfp-mediated cell killing between neuroblastoma and nonneuronal tumor cell lines was statistically significant (P = 0.001). In conclusion, the present study demonstrated the feasibility of a neuroblastoma-selective gene therapy approach using the THp/HSV-tk/egfp expression cassette.     

A case of composite neuroblastoma composed of histologically and biologically distinct clones.

We report a case of a 12-month-old girl with stage 3 neuroblastoma composed of 2 distinct clones in the adrenal primary tumor. One clone showed neuroblastoma, poorly differentiated subtype with a low mitosis-karyorrhexis index (favorable histology), and the other was neuroblastoma, poorly differentiated subtype with a high mitosis-karyorrhexis index (unfavorable histology), according to the International Neuroblastoma Pathology Classification. Fluorescent-labeled in-situ hybridization using the formalin-fixed, paraffin-embedded material showed that the MYCN oncogene was amplified in the latter clone but not in the former clone. Lymph nodes from ipsilateral and contralateral sides contained metastatic neuroblastoma of the latter clone. It is well documented that tumors in the Ganglioneuroblastoma, nodular (composite, Schwannian stroma-rich/stroma-dominant and stroma-poor) category are composite and composed of multiple clones. To our knowledge, however, this is the 1st case report of composite tumor with biologically favorable and unfavorable clones in the Neuroblastoma (Schwannian stroma-poor) category.     

Intracerebral small round cell tumor: an unusual case with EWS-WT1 translocation

Desmoplastic small round cell tumor (DSRCT) is a rare tumor, seen both in children and young adults with a marked predilection for the peritoneal cavity. Histology showed a small round cell tumor with a fibromyxoïd stroma and immunohistochemistry indicated neural and mesenchymal differentiation, and diagnosis was made by molecular detection of the EWS‐WT1 fusion gene product. DSRCT should be considered in the differential diagnosis of intracranial small round cell tumors. Pediatr Blood Cancer 2008;51:545–548. © 2008 Wiley‐Liss, Inc.     

Desmoplastic small round cell tumor of the pleura

Desmoplastic small round cell tumor (DSRCT) is a rare neoplasm with aggressive behavior. Usually it presents as a peritoneal mass, although other cases in various locations have been described. Since less than 10 cases of primary DSRCT in the pleura have been described, it is of interest to report a pediatric case arising from the pleura. The diagnosis was confirmed by molecular detection of the EWS/WT-1 fusion gene product. Multidisciplinary treatment with chemotherapy, radiotherapy, and surgical resection resulted in a progression-free survival time above the median survival, suggesting that this conventional approach could prove effective for this rare and very aggressive malignancy.     

Molecular Genetics in the Diagnosis and Prognosis of Solid Pediatric Tumors

The field of molecular genetics continues to see an ever increasing number of applications to pediatric tumor analysis. Studies in pediatric tumors have identified novel genes and other genetic changes, a large number of which reflect one of the following mechanisms: (1) activation of proto-oncogenes; (2) loss of tumor suppressor genes; or (3) creation of novel fusion proteins. At least one of these mechanisms is operational in each of the following pediatric tumors: neuroblastoma, Ewing sarcoma and peripheral primitive neuroectodermal tumor (pPNET), intra-abdominal desmoplastic small-cell tumor, rhabdomyosarcoma, synovial sarcoma, and Wilms tumor. Out of this research has come not only an increased understanding of oncogenesis but also, for each of the tumors listed above, diagnostic and/or prognostic markers that can be used by the pathologist and oncologist to improve overall patient management. Received November 20, 1997; accepted April 20, 1998.     

Peripheral primitive neuroectodermal tumor presenting with diffuse cutaneous involvement and 7;22 translocation

We report an unusual case of peripheral primitive neuroectodermal tumor (pPNET) in an infant presenting with congenital cutaneous nodules and a t(7;22)(p21;q11.2). The biologic behavior of the tumor diverged over time from a slowly growing tumor with multiple cutane-ous nodules to a more aggressive neoplasm characterized by pulmonary metastases and a soft tissue mass showing additional cytogenetic alterations. Med. Pediatr. Oncol. 30:357–363, 1998. © 1998 Wiley-Liss, Inc.     

Simultaneous occurrence of right adrenocortical tumor and left adrenal neuroblastoma in an infant with Beckwith-Wiedemann syndrome

Children with Beckwith-Wiedemann syndrome (BWS) have increased risk for development of embryonal tumors. We present the case of an infant with BWS who has hypomethylation of LIT1 gene in the 11p15.5 chromosomal region and at 6 months of age presented with simultaneous occurrence of neuroblastoma arising from the left adrenal gland and a right adrenocortical tumor. She underwent surgical resection of both tumors and remains tumor free 18 months after surgery.     

Melanotic Neuroectodermal Tumor of Infancy: A Molecular Genetic Study

Melanotic neuroectodermal tumor of infancy is a rare but well-recognized entity in pediatric pathology. However, the relationship of this tumor to other pediatric small cell tumors with neuroectodermal features (such as neuroblastoma, Ewing sarcoma/peripheral primitive neuroectodermal tumor, and desmoplastic small round cell tumor) is undetermined. Molecular genetic studies of melanotic neuroectodermal tumor of infancy have not been reported. We studied three typical cases of melanotic neuroectodermal tumor of infancy in an attempt to link this tumor to other small cell tumors with well-characterized molecular genetic changes. Tests performed included: detection of MYCN gene amplification and deletion of 1p (all 3 cases), and presence of the t(11;22)(q24;q12) and the t(11;22)(p13;q12) translocations (2 of 3 cases). None of these tests yielded positive results. Thus, there is no genetic basis at present to link melanotic neuroectodermal tumor of infancy to neuroblastoma, Ewing sarcoma/peripheral primitive neuroectodermal tumor, or desmoplastic small round cell tumor. Received June 30, 1997; accepted September 19, 1997.     

LYMPHOKINES POST AUTOLOGOUS PERIPHERAL BLOOD STEM CELL TRANSPLANTATION IN CHILDREN

Malignant ectomesenchymoma (MEM) is a rare soft tissue tumor believed to arise from a pluripotent migratory neural crest cell and composed of both a mesenchymal element and a neuroectodermal element. The authors report the case of an 11-month-old male who presented with a local abdominal MEM and systemic metastases into lungs, liver, bones, and bone marrow. This is the first reported case of an MEM with initial bone marrow dissemination. The tumor consisted of a neuroblastoma component and a mesenchymal component with sarcomatous features. Diagnosis and therapy were complicated by the histological heterogeneity of the tumor, which also influenced the clinical appearance and course in this case. A literature search revealed 15 other evaluated cases that arose in soft tissue and had adequate clinicopathologic data. Complete surgical resection was the mainstay of treatment, and chemotherapy also appeared to be important. In all reported patients ( n = 3) with initial metastases or bone marrow dissemination, as in this case, no cure could be achieved. In patients with disseminated MEM, new therapeutic approaches such as high-dose chemotherapy followed by stem cell rescue should be considered, similar to the current strategy in patients with stage IV neuroblastoma or soft tissue sarcoma.     

Intracranial Ewing sarcoma

The occurrence of primary extraosseous Ewing sarcoma (EES) of the central nervous system (CNS) has only rarely been reported in the literature. It is important to distinguish this entity from the more common central primitive neuroectodermal tumor (PNET) of brain, since the management of these tumors is different from that of EES. We present the clinical, radiologic, and pathologic features of two cases of EES occurring in the brain. The diagnosis was further confirmed by detection of a rearrangement of the FLI1 and/or EWS gene loci in tumors from both patients using fluorescent in situ hybridization (FISH). Although rare, the possibility of EES should be considered particularly when tumors that arise near the meningeal surface of the brain and have the pathologic appearance of a PNET. Demonstration of t(11;22)(q24;q12) by molecular analysis essentially confirms the diagnosis and enables the oncologist to choose appropriate therapy.     

DISSEMINATED MALIGNANT ECTOMESENCHYMOMA (MEM): Case Report and Review of the Literature

Malignant ectomesenchymoma (MEM) is a rare soft tissue tumor believed to arise from a pluripotent migratory neural crest cell and composed of both a mesenchymal element and a neuroectodermal element. The authors report the case of an 11-month-old male who presented with a local abdominal MEM and systemic metastases into lungs, liver, bones, and bone marrow. This is the first reported case of an MEM with initial bone marrow dissemination. The tumor consisted of a neuroblastoma component and a mesenchymal component with sarcomatous features. Diagnosis and therapy were complicated by the histological heterogeneity of the tumor, which also influenced the clinical appearance and course in this case. A literature search revealed 15 other evaluated cases that arose in soft tissue and had adequate clinicopathologic data. Complete surgical resection was the mainstay of treatment, and chemotherapy also appeared to be important. In all reported patients ( n = 3) with initial metastases or bone marrow dissemination, as in this case, no cure could be achieved. In patients with disseminated MEM, new therapeutic approaches such as high-dose chemotherapy followed by stem cell rescue should be considered, similar to the current strategy in patients with stage IV neuroblastoma or soft tissue sarcoma.