CNS Tumors
Transcript of CNS Tumors
CNS tumors
LEARNING OBJECTIVES
• Classify CNS tumors • Describe general characteristics of CNS
tumors• Identify tumor type in relation to age and
site of tumor• Describe primary peripheral nerve sheath
neoplasms with clinical relevance
FACTS
• Tumors in adults are more commonly based in anterior fossa/ supratentorial location whereas childhood tumors are more commonly posterior fossa/ infratentorial in location
• CNS tumors do not metastasize outside the brain and spinal cord.
• Even benign tumors can be sinister according to location.
Tumor origin
Tumor origin
• Neuronal• Glial• Nerve sheath• Meningeal• Others• Metastatic
CNS TUMOR CLASSIFICATION
• Primary tumors- 1/2 --3/4th • Metastatic tumors- 1/4 – ½• In primary tumors,WHO grading is done
according to biologic behaviour into grade I to IV (depending on risk of
recurrence)Under current classification scheme, lesions
of different grades are given distinct names
CNS TUMOR CLASSIFICATION• PRIMARY TUMORS
– Gliomas– Neuronal and glioneuronal tumors– Poorly differentiated tumors– Other parenchymal tumors
Primary lymphomas 1% of intracranial tumorsGerm cell tumors 0.2-1%
Pineal tumors
Tumors of meningesMeningiomas
Nerve sheath tumors SchwannomasNeurofibromas
PRIMARY TUMORS1-Gliomas
Astrocytomas (80% adult primary tumors)OligodendrogliomasEpendymomas and other paraventricular lesions
GradingAstrocytomas
Pilocytic astrocytoma(Non infiltrating)Grade IDiffuse astrocytoma- Grade IIAnaplastic astrocytoma- Grade IIIGlioblastoma multiforme- Grade IV
OligodendrogliomasMost Grade IIAnaplastic Grade III
EpendymomasMost Grade IIAnaplastic Grade III
Gliomas
• SITES and AGE group– Astrocytoma
• Pilocytic (Children , posterior fossa)• Infiltrating (Adults, Cerebral hemispheres)
– Oligodendroglioma• Adults 4th-5th decade, cerebral hemispheres
– Ependymoma (2 groups)• 4th ventricle, children• Intraspinal, adults
Low grade vs High grade glioma
Glioblastoma
Cystic/ Pilocytic astrocytoma
• Gliomas in children,are most common in the posterior fossa. Most childhood brain tumors arise below the tentorium, which is the reverse of the adult.
OLIGODENDROGLIOMA
Ependymoma
• Ependymoma arising from the ependymal lining of the fourth ventricle above the brainstem and bulging toward the cerebellum. Ependymomas are benign histologically.
Ependymoma• This horizontal
section of the brain reveals a large ependymoma of the fourth ventricle.
Ependymoma
Undifferentiated tumors
• Medulloblastoma– Predominantly in children (20% of brain
tumors in children)– Posterior fossa/ cerebellum– Highly malignant but radiosensitive
• Atypical teratoid/ rhabdoid tumor– Children less than 5 yrs– Dismal prognosis
Medulloblastoma• irregular posterior
fossa mass near the midline of the cerebellum and extending into the fourth ventricle in a child.
CNS TUMOR CLASSIFICATION
• METASTATIC TUMORS¼ to ½ of brain tumorsMainly mtastatic carcinomas5 common primaries accounting for 80% mets
– Breast– Lung– Skin (melanoma)– Kidney– GIT
Metastasis from a lung carcinoma. Metastases most often appear at the border of the grey and white matter in the distribution of the middle cerebral artery,
MENINGEAL TUMORS•Meningiomas-Grade I•Atypical meningiomas- Grade II•Anaplastic meningiomas-Grade III
Meningioma
Peripheral nerve sheath tumors
• Schwaanomas• Neurofibromas• Malignant peripheral nerve sheath tumors/
MPNST
Schwaanomas/ Acoustic neuromaThe mass lesion here is arising in the acoustic (eighth cranial) nerve at the cerebellopontine angle. This is a schwannoma. Patients may present with hearing loss. These benign neoplasms can be removed.
SUMMARY (Common tumors)
• Childhood tumors– Medulloblastomas, high grade– Pilocytic astrocytomas, Grade I– Ependymomas, posterior fossa(4th ventricle)– Choroid plexus papillomas, lateral ventricles
• Adult tumors• Gliomas• Spinal ependymomas, oligodendrogliomas
TUMORS of PNS
• NeurofibromaCutaneousPlexiform
• Schwaanoma• Malignant peripheral nerve sheath tumors
NEUROFIBROMA
PLEXIFORM NEUROFIBROMA
PLEXIFORM NEUROFIBROMA