Long-term remission after CD34+-selected PBSCT in a patient with advanced intra-abdominal desmoplastic small round-cell tumor

Bone Marrow Transplantation (2010) 45, 793795

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LETTER TO THE EDITOR

Long-term remission after CD34-selected PBSCT in a patient with advanced intra-abdominal desmoplastic small round-cell tumor

Bone Marrow Transplantation (2010) 45, 793795; doi:http://dx.doi.org/10.1038/bmt.2009.226

Web End =10.1038/bmt.2009.226 ; published online 31 August 2009

Intra-abdominal desmoplastic small round-cell tumor (IADSRCT) is a rare mesenchymal tumor arising from the serosal surface of the abdominal peritoneum with an aggressive clinical course and poor survival (Figure 1). It usually occurs in young males causing obstructive symptoms due to intra-abdominal or pelvic masses, with frequent peritoneal dissemination and metastases to liver, lungs, lymph nodes and BM. A pathognomonic chromosomal translocation, t(11;22)(p13;q12), is found in IADSRCT involving the fusion of the Wilms tumor suppressor gene (WT1) on chromosome 11 to the Ewing sarcoma gene (EWS) on chromosome 22.1 The chimeric gene product may exert a carcinogenic role through a dysregulation of a critical group of target genes. The presence of the specic fusion transcript is not only of diagnostic value but may also be of prognostic signicance,

when monitoring rst-line chemotherapy reveals a persistence in peripheral blood or BM.2 In IADSRCT, tumor regressions have been reported after intensive alkylator-based chemotherapy, combined with surgery and radio-therapy; however, prolonged survival is rare, despite current therapeutic strategies.

We describe the favorable course of a 31-year-old patient with large tumor masses involving the left mesocolon and the pelvic region, showing long-term remission after multi-modality treatment. After complete tumor resection including retroperitoneal lymph node dissection, in which 8 out of 25 lymph nodes showed tumor involvement, the patient received high-dose chemotherapy and autologous transplantation of 3-day ex vivo cultured CD34-selected PBSCs. Detection of the specic EWSexon 7/WT 1exon 8 fusion transcript in tumor cells was performed by reverse transcription-PCR and was also measured on RNA isolated from a frozen sample of the unselected leukapheresis product. Despite the detection of tumor cells in the unselected PBSC product, the patient has remained in CR,

Figure 1 Pathomorphological intra-abdominal desmoplastic small round-cell tumor analysis. Sharply demarcated nests of small-to-medium-sized tumor cells distributed within a dense brous stroma (a) showing a simultaneous expression of antigens characteristic of epithelial (b), muscular (c) and neural (d) differentiation features (a, hematoxylin...