Ball and Socket
Imageing An appearance of the sequelae of epiphyseal fractures with a primary fusion of the central portion of the epiphysis, appearing as a ball within a relatively radiolucent ‘socket’, seen in infantile scurvy, battered child syndrome, and acromelic dwarfism
Parasitology An appearance typical of the trophozoites and occasionally the cysts of Endolimax nana and Iodamoeba buetschlii, in which there is a large, deeply staining karyosome lying in an empty space; the nuclear membrane is not visualized as the chromatin is not peripheral
Rheumatology A descriptor for the radiologic appearance of compressive erosions in the interphalangeal joint of rheumatic diseases, where a central sclerotic zone is surrounded by an osteoporotic ‘ring’