Department of Pathology, University of Oklahoma Health Sciences Center

NeuroTest Question #100 Next question

Answer: (E) Anaplastic medulloblastoma (large cell medulloblastoma).  Level of difficulty: 3 NeuroTest NeuroLearn NeuroHelp

Discussion: 

• Cerebellar liponeurocytoma is a tumor with rather bland histology and is benign. They are typically seen in adults. Histologically, it looks like a classic neurocytoma with the addition of mature adipose tissue. The tumor being shown here is of high histologic grade and has no adipose tissue component and therefore it could not be a cerebellar liponeurocytoma. [click here to see a related case]
• Anaplastic medulloblastoma (large cell) and medulloblastoma: The features of this tumor go along with a medulloblastoma. However, there is too much nuclear pleomorphism and many large nuclei are present. In addition, there is nuclear hugging (one nucleus wrapping another nucleus) (Ú  in Panel B). These features suggest that it is more pleomorphic then the classic medulloblastoma. In fact, they also behave more aggressively then regular medulloblastomas.
• Desmoplastic medulloblastoma (nodular medulloblastoma) is a subtype of medulloblastoma that behaves less aggressively then the regular medulloblastoma. The characteristic is the formation of less cellular pale islands surrounded by more primitive medulloblastoma where reticulin deposition can be found. [Click here to see a picture of desmoplastic medulloblastoma]
• Medulloepithelioma is a type of embryonal tumor that resemble the most primitive developmental (neuroepithelial) stage of neurotube formation. These tumor are highly malignant and are seen in infants and children. Histologically, they have epithelial structure that is supported by a basement membrane. These features are lacking in the case under discussion. [Click here to see the picture of a medulloepithelioma]

Comment: KarMing-Fung@ouhsc.edu