Tumor intraabdominal desmoplásico de células pequeñas y redondas: Revisión de la literatura a propósito de un caso con estudio citológico, histopatológico, inmunohistoquímico y molecular

Purpose: To review the cyto-histopathological, immunohistochemical and molecular characteristics of small round cell desmoplastic tumor (DSRCT). Material and methods: A 18 year old male with an intraabdominal epigastric mass. Results: The tumor consisted of nests and masses of undifferentiated small round cells embedded in a desmoplastic stroma, with areas of rosette formation immuno-reactive to cytokeratins, vimentin, desmin, enolase, and WT1 fraction of the EWS/WT1 fusion protein transcript. The molecular study demonstrated the existence of the translocation t(11 ;22)(p 13 ;q 12). Conclusions: The solid areas and rosette formation have been described in other cases of DSRCT. The chimeric transcription product can be detected by RT-PCR, Southern-blot, Western-blot, and immunohistochemistry. Cytology is especially useful in recurrences. The differential diagnosis should be made with the small round undifferented cell tumors group.