Clinical Data
35-year-old male presents with:
- Progressive headache and ataxia
- Previous medical history was unremarkable
- MRI brain was performed
What do you see?
- Cystic lesion with an enhancing lesion in the posterior fossa on the left side. No enhancement of the cystic wall. Discrete flow voids in the solid nodule.
- Relevant mass effect with compression on the 4th ventricle and obstructing supratentorial hydrocephalus.
What is your differential diagnosis?
- The differential diagnosis of a cyst with an enhancing mural nodule in the posterior fossa includes hemangioblastoma, pilocytic astrocytoma, ganglioglioma and cystic metastasis.
What are the most likely diagnoses?
- When a cystic lesion with a mural nodule is encountered in the posterior fossa, the most likely diagnosis is hemangioblastoma in an adult in the absence of a primary tumor elsewhere. The imaging findings support hemangioblastoma, since the mural nodule shows flow voids on T2 and no enhancing cystic wall. Typically, the cystic wall of hemangioblastoma does not enhance, while a subtle enhancing wall can be discerned in pilocytic astrocytomas.
- The majority of hemangioblastomas occur spontaneously. In case of multiple hemangioblastomas, think about Von Hippel-Lindau syndrome.
- Raz et al. Cyst with a mural nodule tumor of the brain. Cancer Imaging. 2012 Aug 10;12(1):237–244. doi: 10.1102/1470-7330.2012.0028
Pylocitic Astrocitona
Cystic metastasis easily ruled out given the unremarkable past medical history. Not a typical location for ganglioglioma. Inappropriate age for pilocytic astrocytoma. Imaging appearance and infratentorial location together with age and gender (slight male predilection) are highly suggestive of hemangioblastoma.