RESUMEN

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.

Asunto(s)

Tumores Neuroectodérmicos Periféricos Primitivos/patología , Neoplasias del Recto/patología , Sarcoma de Ewing/patología , Antígeno 12E7 , Adolescente , Antígenos CD/metabolismo , Biomarcadores de Tumor , Moléculas de Adhesión Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Humanos , Masculino , Tumores Neuroectodérmicos Periféricos Primitivos/diagnóstico , Tumores Neuroectodérmicos Periféricos Primitivos/genética , Tumores Neuroectodérmicos Periféricos Primitivos/metabolismo , Proteína Proto-Oncogénica c-fli-1 , Neoplasias del Recto/diagnóstico , Neoplasias del Recto/genética , Neoplasias del Recto/metabolismo , Sarcoma de Ewing/diagnóstico , Sarcoma de Ewing/genética , Sarcoma de Ewing/metabolismo , Transactivadores/metabolismo