lym·pho·blas·to·ma \ˌ ̷ ̷ ̷ ̷ˌblaˈstōmə\noun (plurallymphoblastomas \-məz\ ; orlymphoblastoma·ta \-məd.ə\) Etymology: New Latin, from International Scientific Vocabulary lymphoblast + New Latin -oma : any of several diseases of lymph glands marked by the formation of tumorous masses composed of mature or immature lymphocytes