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Epstein-Barr virus (EBV) is asymptomatic in most cases, however, the virus can be linked to pre-malignant lymphoproliferative diseases and to distinct human tumors. They can be classified as leiomyomas or leiomyosarcomas. Diagnosis depends on histopathology and EBV detection. Symptoms are associated with the lesion site. Various treatment modalities are described. It is mainly based on surgical resection, when possible, associated with reduced immunosuppression. It is also associated with targeted therapy and antiviral drugs. The role of surgery and chemotherapy are not well defined yet. A retrospective analysis of patients treated with this diagnosis was carried out at the Pediatric Oncology Institute - GRAACC/UNIFESP - Brazil and Hospital Italiano de Buenos Aires - Argentina, in the period from 2000 to 2020. Three medical records were found and the cases are described. All patients were immunocompromised. Two underwent resection of the tumoral lesion and one only clinical treatment and follow-up because tumors were considered unresectable. Long-term follow-up shows the importance of surgical resection. Surgery has a role in diagnosis too. This tumor is rare, especially in pediatric patients. Although surgical resection has impact in the long-term follow up, surgical treatment should be tailored depending on tumor resectability for each patient. [ABSTRACT FROM AUTHOR]

Background/Purpose Pediatric adrenocortical tumor (ACT) remains a challenging disease. Tumor weight and disease stage are still the most used indicators to prognosis and guidance of clinical decisions. Histology has not added meaningful data for risk stratification and management. ACT is metabolically active, highly vascularized, locally invasive and has the propensity to produce distant metastasis. Our objective was to correlate the expression of vascular endothelial growth factor (VEGF) and intratumoral microvessel density (MVD) with clinical and prognostic aspects in pediatric ACT. Procedure In 27 tumors, immunohistochemical expression of VEGF, CD105 (endoglin) and CD34 was analyzed. MVD was determined by CD34 and CD105 antibodies. MVD and VEGF expression was correlated with clinical characteristics and outcome. Normal pediatric glands were used as controls. Results Endoglin MVD was significantly higher and CD34 MVD was significantly lower in ACT than control. The VEGF expression did not differ between groups. Cytoplasmic staining for endoglin was correlated with hypertension in ACT. Endoglin MVD greater than 1 mv/field, CD34 MVD less than 32 mv/field and VEGF expression levels above 4.8% were associated with clinical and biological indicators of poor prognosis. Conclusions Endoglin and CD34 MVD values are potential histological markers to refine the histologic classification of pediatric ACT. [ABSTRACT FROM AUTHOR]

The childhood sarcomas are malignant tumors with high mortality rates. They are divided into two genetic categories: a category without distinct pattern karyotypic changes and the other category showing unique translocations that originate gene rearrangements. This category includes rhabdomyosarcoma (RMS), Ewing's sarcoma (ES) and synovial sarcoma (SS). Diverse studies have related development genes, such as; IGF2, IHH, PTCH1 and GLI1 and sarcomatogenesis. Objective To characterize the RMS, ES and SS rearrangements, we quantify the expression of IGF2 IHH, PTCH1 and GLI1 genes and correlate molecular data with clinical parameters of patients. Design We analyzed 29 RMS, 10 SS and 60 ES tumor samples by RT-PCR (polymerase chain reaction-reverse transcription) and qPCR (quantitative PCR). Results Among the samples of ARMS, 50% had rearrangements of PAX3/7-FOXO1, 60% of ES samples were EWS-FLI1 positive and 90% of SS samples were positive for SS18-SSX1/2. In relation to the control reference samples (QPCR Human Reference Total RNA-Stratagene, Human Skeletal Muscle Total RNA-Ambion, Universal RNA Human Normal Tissues-Ambion), RMS samples showed a high IGF2 gene expression (p < 0.0001). Moreover, ES samples showed a low IGF2 gene expression (p < 0.0001) and high IHH (p < 0.0001), PTCH1 (p = 0.0173) and GLI1 (p = 0.0113) gene expressions. Conclusions The molecular characterization of IGF and Hedgehog pathway in these pediatric sarcomas may collaborate to enable a better understanding of the biological behavior of these neoplasms. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of our study was to investigate the prevalence of the PAX3/7-FKHR fusion genes and quantify the IGF2 gene expression in rhabdomyosarcoma (RMS) samples. Soft tissue sarcomas account 5% of childhood cancers and 50% of them are RMS. Morphological evaluation of pediatric RMS has defined two histological subtypes, embryonal (ERMS) and alveolar (ARMS). Chromosomal analyses have demonstrated two translocations associated with ARMS, resulting in the PAX3/7-FKHR rearrangements. Reverse transcriptase-polymerase chain reaction (RT-PCR) is extremely useful in the diagnosis of ARMS positive for these rearrangements. Additionally, several studies have shown a significant involvement of IGF pathway in the pathogenesis of RMS. The presence of PAX3/7-FKHR gene fusions was studied in 25 RMS samples from patients attending the IOP–GRAACC/UNIFESP and three RMS cell lines by RT-PCR. IGF2 gene expression was quantified by qPCR and related with clinic pathological parameters. Of the 25 samples, nine (36%) were ARMS and 16 (64%) were ERMS. PAX3/7-FKHR gene fusions expression was detected in 56% of ARMS tumor samples. IGF2 overexpression was observed in 80% of samples and could indicate an important role of this pathway in RMS biology. [Copyright &y& Elsevier]