Dr/ ABD ALLAH NAZEER. MD.

Brain film reading, Lecture 11.

Brain cysts located in the brain are not truly “brain tumors” because

they do not arise from the brain tissue itself. Although they tend to be (benign noncancerous), they are sometimes found in parts of the brain that control vital functions.There are four main types of cysts found in the brain:Arachnoid Cyst (also called Leptomeningeal Cyst): An enlarged, fluid-filled area of the subarachnoid space that occurs in both adults and children.Colloid Cyst: Although scientists are not sure of the definitive cause of colloid cysts, most agree that these cysts begin during embryonic development of the central nervous system. Malignant forms are unknown.Dermoid Cyst: These cysts most likely form during the early weeks of fetal development even though symptoms may not be noticed until years later. They are usually benign.Epidermoid Cyst (also called Epidermoid Tumor): Often referred to as epidermoid tumors. Likely form during the early weeks of fetal development even though the symptoms may not be noticed until decades later.

LocationCysts can appear in a variety of locations within the brain.Arachnoid Cysts appear in the subarachnoid space (between the arachnoid and pia mater layers of the meninges).Colloid Cysts are typically attached to the roof of the third ventricle and the choroid plexus.Dermoid Cysts, though rarely found in the brain, are usually located at the lower back portion of the brain (the posterior fossa) in older adults and in the lower end of the spine in older children and young adults.Epidermoid Cysts tend to be located in the area where the top part of the brain meets the brain stem. Arachnoid Cysts are enlarged, fluid-filled areas between layers of the covering of the brain.Colloid Cysts tend to contain a thick, gel-like substance called colloid.Dermoid and Epidermoid Cysts are tumor-like spheres.

Benign brain CystsColloid cystArachnoid cystsDermoidEpidermoidRathke's cleft cyst

Pineal cystHydatid cyst

MeningiomaBenign Atypical Malignant

CT images showing the arachnoid cyst. There was midline shift and pressure on frontal, temporal, and parietal lobes.

Arachnoid cysts

CP angle Epidermoid cyst.

Epidermoid cyst.

Colloid Cyst of the Third Ventricle.

Colloid Cyst of the Third Ventricle.

Rupture dermoid cyst.

CT scan shows a hyperdense hemorrhagic pineal cyst.

Rathke's cleft cyst

Hydatid cyst.

Meningiomas are the most common extra-axial tumours of the

central nervous system. They are a non-glial neoplasm that originates from the arachnoid cap cells of the meninges. Meningiomas have characteristic imaging findings although there are many variants. They are typically benign with a low recurrence rate but rarely can be malignant.

85-90% supratentorial 45% parasagittal, convexities15-20% sphenoid ridge10% olfactory groove/planum sphenoidale5-10% juxta-sellar5-10% infratentorial<5% miscellaneous intracranialintraventricular meningioma (choroid plexus)optic nerve meningiomapineal glandspinal: especially thoracic (see spinal meningioma)<1% "extra dural”

CT is often the first modality employed to investigate neurological signs or symptoms, and often is the modality which detects an incidental lesion:60% slightly hyperdense to normal brain20-30% have some calcification 72% brightly and homogeneously contrast enhance , less frequent in malignant or cystic variantshyperostosistypical for meningiomas that abut the base of skull S

MR signal characteristics include:T1: isointense: ~60-90%

somewhat hypointense: 10-40% compared to grey matterT1 C+ (Gd): usually intense and homogenous enhancementT2: isointense: ~50%

hyperintense: 35-40%usually correlates with soft textures and hypervascular tumours very hyperintense lesions may represent the microcystic variant

hypointense: 10-15% compared to grey matterDWI: atypical and malignant subtypes may show greater than expected restricted diffusion although recent work suggests that this is not useful in prospectively predicting histological grade

Large Falx Meningioma.

Partially Calcified Meningioma.

Large bifrontal Meningioma.

Axial T1-weighted spin-echo MR image of the brain with intravenous gadolinium enhancement shows dural tail (arrow) attached to a typical meningioma (arrowhead).

Primitive neuroectodermal tumors (PNET) Medulloblastoma Ependymoblastoma Pineoblastoma

Pituitary tumorsPituitary adenomaPituitary carcinoma Craniopharyngioma Rathke's cleft cyst

Pineal Tumors Pineal cyst Pineocytoma Pineoblastoma GerminomaMixed germ cell tumorPineal gliomasPineal teratoma

Choroid plexus tumorsChoroid plexus papillomaChoroid plexus carcinoma

Other, more benign primary tumorsNeurocytomaDysembryoplastic neuroepithelial tumor (DNT)LipomaHemangioblastomaHamartomaTeratoma

Tumors of nerves and/or nerve sheathsNeuromaSchwannomaNeurofibroma

Other primary tumors, including skull baseChondromaChordomaSarcoma Gliosarcoma Chondrosarcoma Rhabdomyosarcoma

Primary Central Nervous System Lymphoma (PCNSL)

Metastatic brain tumors and carcinomatous meningitis

Medulloblastoma.

Medulloblastoma.

Medulloblastoma.

Ependymoma.

Ependymoma.

Pituitary Adenoma.

Typical craniopharyngioma at frontal and lateral MRI scan. The yellow arrows point to the cyst, the red to the solid part of the tumor

Craniopharyngioma.

Germinoma.

Pineal Tumour

MRI of pineal astrocytoma, gadolinium enhanced.

T1-weighted sagittal MRI of teratoma, gadolinium enhanced.

Choroid plexus papillomas.

Choroid plexus carcinoma.

Central Neurocytoma.

Hemangioblastomas

Chordoma at the skull base.

Skull Base Chondroma.

Massive chondrosarcoma of the skull base with extension to the nasal and paranasal cavities and orbita.

Primary CNS lymphoma.

Brain (CNS) Lymphoma.

Brain metastases.

Skull base metastases.

Primary malignant tumors of the brainGliomas

Lowest grade tumorsPilocytic astrocytomaSubependymal giant cell astrocytomaProtoplasmic astrocytomaGangliogliomaXanthomatous astrocytomaSubependymoma

Lower grade malignanciesFibrillary (gemistocytic, protoplasmic) astrocytomaEpendymomaOligodendrogliomaaMixed oligoastrocytomaOptic nerve glioma

Higher-grade malignanciesAnaplastic astrocytomaAnaplastic oligodendrogliomaAnaplastic mixed glioma

Highest-grade malignanciesGlioblastoma multiformeGliosarcomaGliomatosis cerebri

A glioma is a type of brain tumour that grows from glial cells. Glial cells support nerve cells with energy and nutrients and help maintain the blood-brain barrier.Grade 1-pilocytic astrocytoma: Typically occurs in children in cerebellum, brainstem and occasionally at the cerebral hemispheres. It can occur in adults but less commonly. They slow growing and relatively benign. Grade 11-low grade glioma: They typically occur in young adult(20-50y). And most found in the cerebral hemispheres. Some grade 11 glioma evolve into more aggressive tumours(Grade 111 or IV). Grade 111-Malignant glioma: Includes anaplastic astrocytoma, anaplastic oligodendroglioma and anaplastic mixed oligoastrocytoma.Grade IV-Glioblastoma multiforme(GBM): GBM is the most aggressive and most common primary brain tumour. It usually spread quickly and invade other part of the brain.

Pilocytic astrocytoma.

Pilocytic astrocytoma.

Subependymal giant cell astrocytoma

Subependymal giant cell astrocytoma.

PLEOMORPHIC XANTHOASTROCYTOMA

Pleomorphic xanthoastrocytoma.

Ganglioglioma

Subependymoma

Supratentorial Subependymoma in an Adult Patient.

Two cases of Fibrillary Astrocytoma.

Diffusely infiltrating fibrillary astrocytoma.

Ependymoma.

Ependymoma.

Oligodendroglioma.

Oligodendroglioma.

Oligoastrocytoma.

Malignant mixed oligoastrocytoma.

Anaplastic astrocytoma.

Anaplastic astrocytoma.

Anaplastic astrocytoma.

Anaplastic oligodendroglioma.

Anaplastic oligodendroglioma.

Anaplastic Mixed Glioma

Glioblastoma multiforme.

Glioblastoma multiforme.

Glioblastoma multiforme.

Glioblastoma multiforme.

Glioblastoma multiforme.

Gliosarcoma.

Gliosarcoma.

Gliosarcoma.

Gliomatosis cerebri.

Gliomatosis cerebri.

Gliomatosis cerebri.

Multicenteric glioma.

Thank You.