Presentation
Presented with sub-acute onset decreased level of consciousness.
Patient Data
Large midline posterior fossa mass.
Secondary non-communicating obstructive hydrocephalus.
Mass shows heterogeneous increased T2 signal with areas of susceptibility weighted artefact representing areas of hemorrhage. Heterogeneous contrast enhancement.
Marked diffusion restriction. External ventricular drain in situ.
Right parafalcine T2 hypointense lesion with hyperintense rim.
Histology of resected tumor
Multiple fragments of brown white tissue.
Small round clue cells. Syncitial growth pattern. Densely packed and undifferentiated. Homer-Wright rosettes, no perivascular pseudorosettes. Abundant atypical mitoses and apoptotic cells. Reticulin staining shows nodular growth pattern.
Immunophenotyping features consistent with a nodular medulloblastoma (WHO Grade IV).
Case Discussion
Imaging features suggestive of a medulloblastoma (midline posterior fossa with restricted diffusion), confirmed on histology.
Right parafalcine lesion possibly consistent with metastasis.