In most samples infiltrated by non-hematopoietic malignant tumor cells (25/30, 83%), suspicious CD45− tumor cells were CD56+ and lacked expression of all hematopoietic markers tested with ALOT and LymphoclonalTM (smCD3, cyCD3, CD19, CD5, CD20, Igκ, Igλ, CD34, CD7, CD4, CD8, cyCD79a, and nuMPO), except for 2 benign non-hematopoietic vascular tumors (1 hemangiopericytoma and 1 hemangioma) in which tumor cells co-expressed CD34+. This evidence concerns the gene CD34 and hemangiopericytoma.