title: Rectal primitive neuroectodermal tumor.
abstract: We report the clinical, histologic, immunohistochemical, and molecular findings of a Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) localized to the rectum in a 17-year-old boy. Notably the 4.5 x 4 x 4-cm sessile mass was spontaneously eliminated through the anus, producing an episode of hemorrhagic shock. Histologically the tumor presented as a proliferation of membrane CD99-positive, small round cells. EWS/FLI1 chimeric mRNA was demonstrated by nested reverse-transcription polymerase chain reaction (RT-PCR) analysis in the tumor tissue. The patient is alive and well 2 years after initial symptoms. We also review reported cases of ES/PNET of the digestive system.
authors.affiliation: Department of Pathology, Hospital de Niños Superiora Sor María Ludovica, 1900 La Plata, Argentina. patologi@netverk.com.ar
authors.forename: Ricardo
authors.initials: R
authors.lastname: Drut
authors.forename: Mónica
authors.initials: M
authors.lastname: Drut
authors.forename: Carlos
authors.initials: C
authors.lastname: Müller
authors.forename: Adriana
authors.initials: A
authors.lastname: Marrón
mesh_terms: D000071443:12E7 Antigen; D000293:Adolescent; D015703:Antigens, CD / Q000378:metabolism; D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D008297:Male; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D051789:Proto-Oncogene Protein c-fli-1; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012512:Sarcoma, Ewing / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D004268:DNA-Binding Proteins; C078433:FLI1 protein, human; D051789:Proto-Oncogene Protein c-fli-1; D015534:Trans-Activators