BRAIN TUMOR Flashcards
Tentorium Cerebelli
Adult:
Children:
Adult: Supratentorial (cerebrum)
Children: Infratentorial (cerebellum)
Benign Brain Tumors
- Meningioma
- Schwannoma
- Pituitary tumors
- Craniopharyngioma
- Hemangioblastoma
- Dysembryoplastic neuroepithelial tumors (DNT)
- Epidermoid cyst
- Dermoid cyst
- Colloid cyst
Most common primary brain tumor
and adults most commonly affected
Meningioma
Meningioma is attached to the __
and is composed of
- dura mater
- neoplastic meningothelial (arachnoid cap) cells
Risk factor of Meningioma
Prior radiation to the head and neck
Pathogenesis of Meningioma
iinvolves the truncating (inactivating) mutations in the neurofibromatosis 2 (NF2) gene (merlin) on chromosome
22
Histologic patterns of Meningioma
- syncytial (“meningothelial”)
- psammomatous, with psammoma bodies
Meningioma Sporadic meningioma: absence of \_\_ Meningiomas without NF2 mutations: Common site of involvement: Often express \_\_\_ receptors Treatment:
Sporadic meningioma: absence of merlin (50% to 60% of cases)
Meningiomas without NF2 mutations: TNF-receptor associated factor 7 (TRAF7)
Common site of involvement: Sagittal sinus
Often express progesterone receptors
Treatment: Surgery
Involves the Schwann cells on the nerve sheaths.
Adults most commonly at risk.
Schwannoma (Acoustic Neuroma)
Schwannoma (Acoustic Neuroma)
Risk factor:
Hallmark of the genetically distinct neurofibromatosis type 2
Part of ___ neurofibromatosis
Risk factor: patients with NF2
Frequently bilateral: hallmark of the genetically distinct neurofibromatosis type 2
Part of von Recklinghausen neurofibromatosis
Microscopic finding of Schwannoma (Acoustic Neuroma)
Biphasic: compact hypercellular Antoni A areas and myxoid hypocellular Antoni B areas (may be absent in small tumors)
Schwannoma (Acoustic Neuroma)
Diagnostic test:
MRI:
Treatment:
- Gadolinium (contrast) enhanced MRI
- MRI: densely enhancing lesions, enlarging the internal auditory canal and often extending into the cerebellopontine angle -> compression of CN VII and CN V
- Surgery
- Originate from cell rests (remnants of Rathke’s pouch) at the junction of the infundibular stem and pituitary
- Bimodal distribution
- More often in children; adults 55-65 years
Craniopharyngioma
Histologic appearance of Craniopharyngioma
- cords and whorls of epithelial cells (with intercellular bridges and keratohyalin) separated by a loose network of stellate cells
- Cyst contains dark albuminous fluids, cholesterol crystals, ad calcium deposits
Craniopharyngioma
is found in
- On the optic chiasm or cranial nerves
- Frequently bulge into the floor of the third ventricle and base of the brain
- Located in the cerebellum
- Most often in connection with von Hippel-Lindau syndrome
- Age at onset: 15-50 years
- Blacks, Whites, and Asians are equally affected
Hemangioblastoma
Hemangioblastoma
Risk factor:
Angiographic picture:
MRI:
Risk factor: autosomal dominant inheritance of VHL
Angiographic picture: tightly packed cluster of small vessels forming a mass 1 to 2 cm in diameter
MRI: cerebellar cyst containing an enhancing nodular lesion on its wall
Clinical presentation:
- Dizziness
- Ataxia of gait or of the limbs on one side
- Increased intracranial pressure from compression of the fourth ventricle
- Retinal angioma of hepatic and pancreatic cysts
- Polycythemia vera
Hemangioblastoma
Treatment of Hemangioblastoma
craniotomy with opening of the cerebellar cyst, and excision of the mural hemangioblastomatous nodule
- Located in the supratentorial area of the temporal lobe
- In children and young adults
- Males usually affected
Dysembryoplastic Neuroepithelial Tumors (DNT)
Microscopic findings:
Dysembryoplastic Neuroepithelial Tumors (DNT)
- Uniform oligodendroglioma-like cells in a mucin-rich background
- Hallmark: specific glioneuronal elements (columns formed of axons lined by uniform oligodendroglioma-like cells) with intervening floating neurons (cortical neurons in mucin pools)
MRI:
Hyperintense; ‘bubbly appearance
Enhancement (1/3 of cases): heterogeneous or multiple ring pattern
CT:
May show calcification, may scallop the inner table of the skull vault
Dysembryoplastic Neuroepithelial Tumors (DNT)
Dysembryoplastic Neuroepithelial Tumors (DNT)
Predisposing factor:
Clinical presentation:
Treatment:
Predisposing factor: long-standing history of seizures
Clinical presentation: Chronic partial seizures in supratentorial tumors
Treatment: Gross total resection or even subtotal resection
Consists of squamous epithelial cells surrounding a keratin-filled cyst. On the cerebellopontine angle and the intra- and suprasellar regions. Well defined round mass, thin walled, pearly white.
Epidermoid Cysts
Epidermoid Cysts
MRI:
Miscroscopic findings:
MRI: extra-axial lesions with characteristics that are similar to CSF but have restricted diffusion
Microscopic finding: Fibrous wall lined by keratinizing squamous epithelium; contains anucleate squames but no skin adnexae and no hair
Clinical presentation of Epidermoid Cysts
Treatment
- Headache
- Cranial nerve abnormalities
- Seizures
- Hydrocephalus
Tx: Surgery
