– Presenting with mixed hearing loss.
What do you see on the image? What is the most likely diagnosis?
Bilateral asymmetrical temporal and inferomedial frontal lobes and insular cortices
Abnormal CT hypodensity and high FLAIR signal intensity of the affected white matter and cortex
Herpes encephalitis: affects the limbic system bilaterally, temporal lobes, insular cortices and inferolateral frontal lobes. May progress to hemorrhage. Basal ganglia is typically spared
Paraneoplastic tumor-related limbic encephalitis and autoimmune limbic encephalitis: tumour-related limbic encephalitis and autoimmune limbic encephalitis: autoimmune encephalitis. Same distribution as herpes encephalitis but the basal ganglia is frequently involved. Hemorrhage is uncommon
* Presenting with dizziness, vertigo and loss of coordination
A focal expansile single lesion.
* With moderate perilesional edema and mass effect deforming the 4th ventricle without signs of active hydrocephalus (not shown)
* With avid enhancement
Left posterior fossa.
Suggestive of extraaxial location:
1) Peripheral location and wide dural contact
2) Changes in the adjacent skull vault bone
3) Dural Tail
Definitive for extraaxial location:
1) CSF cleft.
2) Interposed vessels, cortex or dura.
The lesion is intraaxial, located in the left cerebellar hemisphere.
* HEMANGIOBLASTOMA: Most frequent posterior fossa primary tumour in adults. Strong association with von Hippel Lindau disease. Cystic tumour with mural peripheral solid avidly enhancing nodule. Perilesional pathologic vessels.
* METASTASES: Most frequent posterior fossa tumour in adults. Expanisve focal lesion, single or multiple, well defined, solid-necrotic, great edema, and mass effect.
* GLIOMA: Pilocytic astrocitomas (cystic tumour with solid mural nodule) and diffuse brainstem gliomas (often low-grade, infiltrative, ill-defined lesions without enhancement) much more common in peadiatric population. High-grade gliomas (infiltrative ill-defined lesions with heterogeneous enhancement and necrosis) are uncommon in the posterior fossa.
* MEDULLOBLASTOMA: Paediatric population (more common): Intraventricular, midline; young adults; parenchymal, paramedial, focal solid enhancing lesion. Different subtypes that share hypercellularity as main feature: CT hyperdense, T2 Hypointense and difussion restriction. High propensity for CSF dissemination.
* LYMPHOMA: Focal solid enhancing single lesion or multiple cloud-like enhancing lesions. Hypercellularity as main feature: CT hyperdense, T2 hypointense and diffusion restriction.
* SUBEPENDYMOMA: Adults, intraventricular 4th ventricle. Plastic. None or little enhancement.
* EPENDYMOMA:Paediatric population: intraventricular posterior fossa; young adults: supratentorial periventricular. Plastic, heterogeneous, solid-necrotic, enhancing tumour.
* MENINGIOMA: Calcifications and bone hyperostosis
* SCHWANNOMA: Intralesional cyst and bone remodelling
* EPIDERMOID: No enhancement, restricted diffusion
* ARACHNOID CYST: CSF behaviour
There are two most reasonable diagnostics.
MEDULLOBLASTOMA AND LYMPHOMA : Could be appropiate diagnositc options for a lesion with this semiology.
The final histologic diagnosis was: Primary CNS lymphoma
* Acute infarct
* Low relative cerebral blood volume (rCBV) assessed in the colour maps
* T1 Leakage effect assessed in the curve could have helped in the preoperative diagnostic of lymphoma against medulloblastoma.