panmyelophthisis

noun

pan·​my·​e·​lo·​phthi·​sis -ˌmī-ə-lō-ˈt(h)ī-səs, -ˈt(h)is-əs 

plural panmyelophthises -ˈt(h)ī-ˌsēz, -ˈt(h)is-ˌēz 

: wasting or degeneration of the blood-forming elements of the bone marrow