Pre‐B‐cell acute lymphoblastic leukemia with bulk extramedullary disease and chromosome 22 (EWSR1) rearrangement masquerading as Ewing sarcoma

Abstract

We report a 2‐year‐old female with a subcutaneous tumor who was initially misdiagnosed as suffering from Ewing sarcoma with a positive EWSR1 rearrangement and EWS/FLI1 transcript. After finding lymphoblasts in peripheral blood, the diagnosis of acute lymphoblastic leukemia was established. This necessitated further analysis of the subcutaneous tumor. The tissue was positive for immature B‐cell markers and an immunoglobulin heavy chain gene rearrangement, which confirmed the final diagnosis of common type acute lymphoblastic leukemia with bulk extramedullary disease. The patient was treated with chemotherapy and was in remission 30 months after the diagnosis. Pediatr Blood Cancer 2010;54:606–609. © 2009 Wiley‐Liss, Inc.

Blastic plasmacytoid dendritic cell neoplasm with EWSR1 gene rearrangement

“…EWSR1 gene rearrangements have been described in haematopoietic malignancies including acute myeloid leukaemia, granulocytic sarcoma and pre-B-cell acute lymphoblastic leukaemia 6 7. Our result suggests that EWSR1 gene rearrangement might play a role in pathogenesis of BPDCN.…”

A zebrafish transgenic model of Ewing’s sarcoma reveals conserved mediators of EWS-FLI1 tumorigenesis

“…Although EWS-FLI1-associated leukemia is not observed in humans, a closely related fusion of TLS-ERG is associated with acute myeloid leukemia (Ichikawa et al, 1994). Rare cases of pre-B-cell lymphoblastic leukemia with the EWS-FLI1 translocation have also been reported (Ozdemirli et al, 1998; Jakovljevic et al, 2010). These cases suggest a connection between EWS translocation proteins and cancers of the hematopoietic lineage.…”

Ewing sarcoma family of tumours: unusual histological variants and immunophenotypic characteristics

“…CIC-DUX4) have also been reported and whether these ESFT-like tumours should be diagnosed as ESFT or "undifferentiated sarcomas" remain controversial. 2,54e58 Isolated cases of mixed embryonal and alveolar rhabdomyosarcomas, 59 polyphenotypic tumours, 59 neuroblastoma, 60 pre Bcell acute lymphoblastic leukaemia/lymphoma, 61 and small cell anaplastic large cell lymphomas 62 harbouring either EWSR1-FLI1 or EWS/ERG translocations have been reported and appear to be once-off events without subsequent case reports. One case of mesenchymal chondrosarcoma has been reported with t(11;22)(q24;q12) on cell culture but without confirmation of EWSR1-FLI1 fusion product.…”