CT is excellent for demonstrating dystrophic calcifications in the teratoid type. Correct diagnosis of medulloblastoma may require ruling out atypical teratoid rhabdoid tumor. Atypical teratoid/rhabdoid tumor was first described as a distinct entity in 1987. Less commonly, and seen usually in infants, are teratomas and atypical teratoid rhabdoid tumors. Diktyoma is classified into teratoid and nonteratoid types, based on heteroplastic tissue in the former. In 2000, his Teratoid Heights comic was published by Highwater Books. About 30-50 percent of diktyomas contain heteroplastic elements, and thus belong to the teratoid subtype. An atypical teratoid rhabdoid tumor (AT/RT) is a rare tumor usually diagnosed in childhood.