Presentation on theme: "November 2010 Janica Walden, MD (Neuroradiology Fellow) and Thomas Bouldin, MD (Neuropathologist)"— Presentation transcript:
November 2010 Janica Walden, MD (Neuroradiology Fellow) and Thomas Bouldin, MD (Neuropathologist)
Case # 1 Young adult male with PMH significant for NF-1 Had been followed over the past few years for a tectal glioma with secondary ventriculomegaly The lesion and ventriculomegaly had been stable. The patient had been doing well until he died suddenly.
Imaging Brain MRI performed four months before death, when compared with prior MRIs, showed Stable tectal mass, most compatible with a glioma Stable dilatation of the lateral and third ventricles Stable enhancing lesions within the left basal ganglia and right frontal lobe white matter Stable abnormal T2 hyperintense signal in the cerebellar vermis.
Clinical Course Although the patient had been doing well, he died suddenly. Postmortem MRI of the brain was performed in order to gain more insight as to the cause of death.
Postmortem Imaging-MRI The tectal glioma did not change in size or demonstrate any evidence of hemorrhage between the last premortem MRI and the postmortem MRI. There is development of lateral and third ventricular hydrocephalus between the two studies. The suggestion of trans-ependymal flow of CSF in the postmortem study may be an artifact. There is evidence of aqueductal obstruction.
Sagittal postmortem T1WI shows obstruction of cerebral aqueduct (arrow) by tumor.
Left panel: Section through formalin-fixed, postmortem specimen of midbrain and upper pons. A gray, gelatinous neoplasm is present in the midbrain in the region of the cerebral aqueduct. No cerebral aqueduct is identifiable in this section macroscopically. Right panel: The tectal glioma has histologic features of a pilocytic astrocytoma.
Usual Causes of Sudden Death Related to Intracranial Pathology Epilepsy (sudden unexplained death in epilepsy) Intracerebral hemorrhage Spontaneous subarachnoid hemorrhage Subdural hematoma Epidural hematoma Bacterial Meningitis Brain tumor Data from Black M, and Graham DI. Sudden unexplained death in adults caused by intracranial pathology. J Clin Pathol 55:44–50, 2002.
Tectal Glioma Expands tectum & obstructs aqueduct T2 hyperintense mass, may or may not enhance Tectal glioma: Most indolent, often only need CSF diversion Often associated with NF-1 Focal areas of signal intensity in white matter & deep gray matter; typically involve globus pallidus May involve brainstem 80% 5-year progression free survival Progression or dissemination is extremely rare.
Tectal Glioma: MRI High signal T2; minority isointense Expands tectum; obstructs aqueduct early Remains focal: Tectum/tegmental; (+/-) cerebral peduncles, thalami FLAIR: High signal T1WI C+: Variable enhancement T2* GRE: Tectal: Hazy calcification, may extend up crura to thalami
Case #2 40 year-old male with 4-month history of blurry vision in his left eye Initially evaluated by an ophthalmologist, with MRI of brain performed at an outside facility MRI revealed extra-orbital mass behind the left eye. The patient was referred to a neurosurgeon.
Imaging MRI showed an extra-axial, dural-based mass along the left sphenoid wing, most consistent with a meningioma. The mass surrounded the ICA. There was enhancement along the left optic nerve, possibly reflecting extension of the mass or a dural reaction.
Clinical Course Given the patient’s deteriorating vision in his left eye, surgical resection was recommended in order to preserve vision. A left pterional craniotomy for decompression of the left optic nerve and for biopsy of the lesion were performed. Pathology was consistent with neurosarcoidosis. Post-operatively, patient had improved vision in left eye. Rheumatology was consulted for further treatment.
Photomicrograph of a histologic section from the biopsy of the intracranial mass shows granulomatous inflammation with several multinucleated giant cells (arrows). Special stains were negative for mycobacteria and fungi. The histologic changes are consistent with sarcoidosis.
Sarcoidosis Etiology remains unknown. CNS is involved in 5% (clinical) to 27% (autopsy) of cases per 100,000 in North America Most common symptom: CN deficit(s), most often facial nerve palsy Onset in 3rd-4th decades Gender: M:F = 2:1 African-American: Caucasian-American = 10:1 Often indolent disease, with up to 50% asymptomatic
Neurosarcoidosis Multisystem inflammatory disease characterized by noncaseating epithelioid-cell granulomas Best diagnostic clue: Solitary or multifocal CNS mass(es) plus an abnormal chest radiograph 50% have periventricular T2 hyperintense lesions Infiltrates perivascular (Virchow-Robin) spaces of brain May cause a small vessel vasculitis
Neurosarcoidosis: MRI Wide spectrum of MRI enhancement patterns Slightly > 1/3 have multiple parenchymal lesions Slightly > 1/3 have leptomeningeal involvement, nodular and/or diffuse 10% solitary intra-axial mass 5-10% hypothalamus, infundibular thickening 5% solitary dural-based, extra-axial mass Other: Vasculitis or ependymal enhancement DDx when dural based: meningioma
Neurosarcoidosis: MRI T2WI Lacunar infarcts (brainstem, basal ganglia) Hypointense material within subarachnoid space/sulci, focally or diffuse Hypointense dural lesion(s) FLAIR ≈ 50% have periventricular T2 hyperintense lesions Hyperintense vasogenic edema 2° to Infiltration of perivascular (Virchow-Robin) spaces May cause a small-vessel vasculitis.
Case #3 10 year-old child with intractable seizures who was previously healthy until recent onset of generalized tonic-clonic seizures and petit-mal seizures Managed on anticonvulsants until 3 weeks prior to admission when child began to have worsening seizures and gait instability EEG showed persistent epileptiform activity, localized to the right hemisphere, with highest amplitude in temporal and parietal regions.
Imaging MRI showed: Atrophy and abnormal T2 signal within right hippocampus, suggesting right mesial temporal sclerosis Areas of abnormal increased T2/FLAIR signal are within the cortex and subcortical white matter of the posterior right parietal lobe, right frontal lobe, and right occipital lobe. Differential Dx includes post-ictal changes and encephalitis.
Histologic sections of cerebral cortex from brain biopsy. Left panel: In center of photomicrograph is a cluster of cells forming a “microglial nodule.” Right panel: Chronic inflammatory cells surround a blood vessel in the cerebral cortex. Microglial nodules and perivascular chronic inflammation are hallmarks of encephalitis.
Rasmussen Encephalitis Chronic, progressive, relentless, unilateral inflammation of brain of uncertain etiology Characterized by hemispheric volume loss and difficult to control focal seizure activity 50% preceded by inflammatory episode Usually begins in childhood (6-8 years of age) Refractory to antiepileptic medications Unilateral progressive cortical atrophy
Rasmussen Encephalitis: MRI T1WI: Blurring of cortical ribbon during early swelling; T2WI Early focal swelling of gyri Gray, underlying white matter mildly hyperintense +/- Basal ganglia, hippocampi involved Late: Atrophy of involved cerebral hemisphere or lobe. FLAIR: small areas of hyperintensity that progressively increase over time Late: Atrophic, encephalomalacic/gliotic residual brain. MRS: ↓ N-acetyl-aspartate (NAA) and choline; ↑ myo- inositol, and ↑ glutamine/glutamate
Case # 4 60 year-old female with history of breast lymphoma diagnosed two years ago Status post chemotherapy and radiation. Now presents with progressive weakness, unsteadiness, intermittent confusion, and right arm tremor.
Imaging Findings Enhancing left parietal lesion, concerning for metastatic disease Abnormal signal in the left basal ganglia with expansion of the left caudate nucleus and lentiform nucleus; peripheral hyperintensity and central hypointensity on T2WI; no enhancement Differential diagnosis includes lymphoma
Photomicrograph of histologic section from brain biopsy shows poorly differentiated neoplasm. Immunohistochemical stains confirmed that this is a diffuse large B-cell lymphoma. The primary breast lymphoma was also a diffuse large B-cell lymphoma.
Metastatic CNS Lymphoma Secondary spread of lymphoma to CNS is usually in the form of leptomeningeal infiltrates. Parenchymal lesions, when present, usually result from secondary involvement from the leptomeninges. Via infiltration of pervascular spaces Poor prognosis Periventricular dissemination is rare.
Metastatic CNS Lymphoma: MRI T1WI: Single or multiple iso-or hypointense lesions T2WI: Homogeneously iso-or hypointense to cortex FLAIR: nonsuppression of CSF in sulci with leptomeningeal involvement Diffusely enhances if dural mass; may see leptomeningeal enhancement
Case # 5 3 year-old child presented with a 3-week history of nausea and vomiting as well as headaches of increasing frequency and intensity. CT scan revealed an intraventricular mass within the 4 th ventricle and associated ventriculomegaly.
Imaging MRI of the brain showed a 5.9 cm x 2.5 cm x 2.5 cm, partially cystic, enhancing mass expanding the 4 th ventricle and extending inferiorly through the foramina of Magendie and Monroe. Adjacent mass effect on brainstem and cerebellum Increased perfusion within the mass Given imaging characteristics, ependymoma was favored diagnosis.
Photomicrograph of a histologic section from the biopsy of the tumor shows a glioma with prominent perivascular pseudorosettes. Pseudorosettes are a characteristic histologic finding in ependymoma.
Ependymoma Slow-growing tumor of ependymal cells Third most common posterior fossa tumor in children (after pilocytic astrocytoma and medulloblastoma) 20-30% of intramedullary spinal tumors in children DDx: Medulloblastoma and cerebellar pilocytic astrocytoma Gross total resection plus radiation therapy correlates with improved survival.
Ependymoma: Imaging Findings Soft or "plastic" tumor squeezes out through 4th ventricle foramina into cisterns. 2/3rd infratentorial, 4th ventricle 1/3rd supratentorial, majority periventricular white matter Calcification is common (50%); +/- cysts, hemorrhage