In the 2016 World Health Organization (WHO) classification of CNS tumors, the histological classification of medulloblastoma was comprised of four morphological subtypes: i) classic, ii) desmoplastic/nodular, iii) medulloblastoma with extensive nodularity, and iv) large cell/anaplastic. ¹ The 2021 classification guidelines combine these into one section: “medulloblastoma, histologically defined,”. Importantly, when applicable, a combination of molecular and histopathological features should be simultaneously considered to further refine these subtype classifications. ^2-5

Additional details are described in the 2021 WHO Classification of Tumors of the Central Nervous System.