CD56 and CD57 are commonly considered as natural killer and neuroectodermal markers, but their expression has been identified in a wide spectrum of neoplasms including some cases of Ewing's sarcoma (ES) and primitive neuroectodermal turner (PNET). We report two cases of small, round blue cell tumor (SRBCT), in which flow cytometry immunophenotyping (FCI) detected strong expression of CD56 and CD57 (one case). Immunohistochemical staining with Leu-19 and Leu-7 con firmed the FI results. Although CD56 and CD57 expression is consistent with ES/PNET, it can be potentially misleading if results of FCI are interpreted in the absence of other findings. These cases suggest the utility of FCI in undifferentiatedd SRBCT. The literature on CD56 and CD57 expression in ES/PNET is reviewed and discussed.
- Ewing's sarcoma
- Flow cytometry
- Primitive neuroectodermal tumor
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Molecular Biology
- Cell Biology