Flow cytometry used to identify histiocytic sarcoma: A case report.

Histiocytic sarcoma (HS) is an extremely rare but aggressive malignancy of hematopoietic origin. The diagnosis of HS mainly relies on pathological morphology and immunohistochemical staining combined with clinical symptoms. However, whether histiocytic sarcoma can be detected using flow cytometry (FCM) is not clear. We report the case of a 61-year-old female patient with a group of abnormal cells identified primarily by FCM. Largeabnormal cells -CD68+ CD11c+ CD14+ HLA-DR+ CD123+ CD45+ presented in upper forward scatter and side scatter, indicating that a malignancy originally derived from monocyte/macrophage could be histocytic sarcoma. This patient with histiocytic sarcoma was finally confirmed with pathology and immunohistochemistry. In conclusion, HS can be detected by assessment of CD68+ CD11c+ CD14+ HLA-DR+ CD123+ CD45+ cells using FCM, suggesting that FCM can be an effective tool for early finding of HS. © 2015 International Clinical Cytometry Society.