A case report of a cerebellar neuroblastoma in a p53 null mutation mouse.

We report a case of cerebellar neuroblastoma in a 19-week-old p53 null mutation mouse. A white and soft mass was observed at the cerebellar vermis. Histologically, the tumor consisted of solid growth of round to oval pleomorphic cells with frequent mitotic figures. While there were no typical cellular arrangements of embryonic neurogenic tumors, such as Homer-Wright rosette, perivascular pseudorosette, or streaming of neoplastic neurocytes, small populations of the neoplastic cells were immunohistochemically positive for synaptophysin, microtubule-associated protein 2, S-100 and nestin. Both glial fibrillary acidic protein and vimentin were entirely negative in the neoplastic cells. Based on the biological characteristics of neoplastic cells, this tumor was diagnosed as neuroblastoma of the cerebellar origin.