Abstract
We report the case of an 11-year-old girl with a retroperitoneal tumor in the left upper quadrant. The girl was admitted to hospital with weight loss and a painless abdominal mass that on biopsy was diagnosed as a peripheral primitive neuroectodermal tumor/Ewing sarcoma (pPNET/EWS) of the soft tissue. The patient underwent chemotherapy followed by surgical resection of the tumor 5 months after diagnosis. The posttreatment residual viable tumor showed a morphologic appearance resembling a neuroblastoma. Interphase and metaphase fluorescent in situ hybridization (FISH) studies performed on the pretreatment and posttreatment samples showed the presence of a t(11;22) rearrangement resulting in EWSR1/FLI1 gene fusion consistent with pPNET/EWS in both specimens. This case is unusual in the sense of showing the typical gene fusion for pPNET/EWS both in the pretherapy sample with the typical morphological appearance of this tumor and in the posttherapy specimen showing neural differentiation suggestive of a neuroblastoma.
MeSH terms
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Antineoplastic Combined Chemotherapy Protocols / therapeutic use*
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Cell Differentiation*
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Child
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Chromosomes, Human, Pair 11
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Chromosomes, Human, Pair 22
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Cyclophosphamide / therapeutic use
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Dactinomycin / therapeutic use
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Disease-Free Survival
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Female
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Follow-Up Studies
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Humans
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In Situ Hybridization, Fluorescence
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Karyotyping
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Neuroblastoma / physiopathology*
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Neuroectodermal Tumors, Primitive, Peripheral / diagnosis
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Neuroectodermal Tumors, Primitive, Peripheral / drug therapy*
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Neuroectodermal Tumors, Primitive, Peripheral / genetics
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Neuroectodermal Tumors, Primitive, Peripheral / metabolism
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Neuroectodermal Tumors, Primitive, Peripheral / pathology
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Neuroectodermal Tumors, Primitive, Peripheral / physiopathology*
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Neuroectodermal Tumors, Primitive, Peripheral / radiotherapy
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Neuroectodermal Tumors, Primitive, Peripheral / surgery
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Oncogene Fusion
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Radiotherapy, Adjuvant
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Time Factors
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Tomography, X-Ray Computed
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Translocation, Genetic
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Vincristine / therapeutic use
Substances
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Dactinomycin
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Vincristine
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Cyclophosphamide