Histiocytic sarcoma (HS) is an extremely rare hematopoietic neoplasm that originates from the macrophage lineage and shows a sarcoma‐like spread of CD4+, CD68+, PU.1+, and CD163+ histiocytic cells [20, 27, 107, 108, 109]. This evidence concerns the gene SPI1 and histiocytic sarcoma.