Case 091

History/Physical

History/Physical:

15-year-old right-handed male.

Previous suboccipital craniectomy.

Gait ataxia over past month.

There has been a prior suboccipital craniectomy (arrows). There is recurrent disease (*). These nodules have high attenuation suggesting hypercellularity.

Recurrent disease in the original site (*). Recurrent disease remote to the original site (arrow) from CSF spread.

Diagnosis: Medulloblastoma, classic (non-WNT, non-SHH)

Densely cellular ‘small blue cell’ lesion with moderate pleomorphism and weak rosette formation (*).

Primitive cells with high nucleus:cytoplasm ratios, nuclear molding (arrow) and mitotic activity (arrowhead).