Desmoplastic Medulloblastoma

Desmoplastic medulloblastoma has a characteristic appearance on low power consisting of round pale nodules of tumor separated by zones of darker tumor cells. The pale nodules are composed uniform round to spindle shaped neuronal-appearing cells which are not as active mitotically as the surrounding darker tumor. They are present within a reticulin-poor fine fibrillary background composed of neurites or neuronal processes. The nodular areas often show strong immunoreactivity for synaptophysin and GFAP supporting the idea that they represent islands of maturation. Desmoplastic medulloblastoma has a better prognosis than the classic form.