cholesteatoma

noun

cho·​les·​te·​a·​to·​ma kə-ˌles-tē-ə-ˈtō-mə, ˌkō-lə-ˌstē-, ˌkäl-ə- 

plural cholesteatomas also cholesteatomata -mət-ə 

1

: an epidermoid cyst usually in the brain arising from aberrant embryonic rests and appearing as a compact shiny flaky mass

called also pearly tumor

2

: a tumor usually growing in a confined space (as the middle ear or mastoid) and frequently constituting a sequel to chronic otitis media

cholesteatomatous

-mət-əs 

adjective