histiocytoma

noun
his·​tio·​cy·​to·​ma | \ ˌhis-tē-ō-sī-ˈtō-mə How to pronounce histiocytoma (audio) \
plural histiocytomas also histiocytomata\ -​mət-​ə How to pronounce histiocytomata (audio) \

Medical Definition of histiocytoma

: a tumor that consists predominantly of macrophages a malignant fibrous histiocytoma of the spleen