Neuro tumors Flashcards
Characteristics of astrocytoma
Originates from atrocytes
Immunoreactivity for glial fibrillary acidic protein (GFAP) and diffuse (ill-demarcated) pattern of growth
Pilocytic astrocytoma is a well-differentiated, benign astrocytic tumor that arises throughout the neuroaxis; it is common in children and young adults
Sites of involvement include posterior fossa (cerebellum) and diencephalon
Radiographical characteristics of astrocytoma
Most show cystic lesion with a mural nodule
Histologically characteristics of astrocytoma
Shows spindly neoplastic astrocytes with long bipolar processes
Rosenthal fibers
What are rosenthal fibers?
Thick, corkscrew-like eosinophilic structures that derive from hypertrophic processes of atrocytes
Characteristics of fibrillary (diffuse) astrocytoma
Low grade tumor that arises in the cerebral hemisphere of young to middle-aged and the brainstem of children
IDH1 positive
Characteristics of anaplastic astrocytoma
Cellular, pleomorphic and mitotically active
Characteristics of glioblastoma
Most common CNS primary malignancy in adults
Histological characteristics of gliomblastoma
Shows necrosis and/or vascular proliferation in addition to features seen in anaplastic astrocytoma
Characteristics of glioblastoma multiforme
Tendency to cross midline by involving the corpus callosum (“butterfly glioma”)
Characteristics of oligo dendroglioma
Occurs more often in adults than in children
Cortical location; may cause seizures
Slow-growing
Tumors with deletions of 1P or 19q respond well to therapy
Histological characteristics of oligo dendroglioma
Perinuclear halos are a fixation artifact that is not seen on frozen section
Characteristics of ependymoma
Located in the fourth ventricle in children, where it presents with obstructive hydrocephalus
In adults the spinal cord is the most common site
Multifocality in the spinal cord is associated with NF2
Histological characteristics of ependymoma
Pseudorosettes are a helpful diagnostic feature on microscopic study
Characteristics of embryonal (primitive) tumors
Group of small round cell tumors that occur predominantly in children
In the cerebellum they are called medulloblastoma
Most common malignant brain tumor in children
Characteristics of schwannoma
Originates from schwann cells of cranial or spinal nerves
Most frequent location is on CN8 at the cerebellopontine angle (CPA)
Manifests characteristically with unilateral loss of hearing and tinnitus
Prognosis good after resection
S100 positive
NF1
NF2 schwannoma
Bilateral acoustic schwannoma
Histological characteristics of schwannoma
Has spindly cells arranged in hypercellular Antoni A areas; alternating hypocellular Antoni B areas
Verocray bodies
What are verocay bodies?
Parallel rows of neoplastic Schwann cells
Characteristics of meningioma
Originates from meningothelial cells of the arachnoid
Common in adults (F>M), rare in children
Dura based mass
Clinical features: Headache, seizures and neurological deficits
Abnormalities of chromosome 22 sometimes present
Multiple meningiomas occur in NF2 patients
Histological characteristics of meningioma
Shows cellular whorls and psammoma bodies
Syncytial pattern is common
Characteristics of craniopharyngioma
Arises from odotogenic epithelium within the suprasellar/diencephalic region
Most commonly affects children and young adults
Most common presenting symptoms: Headache, hypopituitarism, and visual field disturbances
Contains deposits of calcium
Benign but tends to recur after resection
Beta-catenin (CTNNBIc) gene mutations have been reported
Histological characteristics of craniopharyngioma
Shows squamous cells
Characteristics of lymphomas
Most common CNS tumor in the immunosuppressed
May be multiple
Don’t respond well to chemo
Characteristics of germ cell layers
More common in children than adults
Histological characteristics of germ cell tumors
Germinoma most common histologic type
Characteristics of Sturge-Weber syndrome
Also known as Encephalotrigeminal angiomatosis
Presentation:
Facial angioma (Port-wine stain) in the V1 + V2 distribution of trigeminal nerve
Leptomeningeal angioma, often same side as the port-wine stain
Associated conditions:
Mental retardation
Epileptic spam at infancy
Early onset glaucoma
Skull radiopacities ("Tram track" calcification)
Characteristics of Charcot-Marie-Tooth disease
Also known as hereditary motor and sensory neuropathy (HMSN)
Mutations in a peripheral myelin protein (PMP22) forms unstable myelin
Distal symmetric sensorimotor polyneuropathy with atrophy of the calf muscles (“stork legs”) and pes cavus deformity
Nerve conduction studies: decrease impulse conduction velocity
Histological characteristics of Charcot-Marie-Tooth disease
Nerve biopsy-segmental demylination and remyelination with onion bulb formation
Characteristics of neurofibroma
Heterogenous in composition- Schwann cells are admitted with perineural-like cells, fibroblasts, mast cells and CD34+ spindle cells
Solitary are not associated with NF1
Multiple are associated with NF1
Often young, 20-30
Classifications of neurofibroma
Cutaneous or dermal
Diffuse
Plexiform
Characteristics of cutaneous or dermal neurofibroma
Small nodular tumors of the skin and subcutaneous tissue, arising from small cutaneous nerves
Characteristics of diffuse neurofibroma
present as large plaque-like elevation of skin
Characteristics of plexiform neurofibroma
multiple nodular masses affecting nerve roots, plexuses or large nerves (appear as “bag of worms”)
Characteristics of malignant peripheral nerve sheath tumors (MPNST)
Mostly high grade tumors, but uncommon
Can be sporadic tumors or NF1-associated tumors arising through malignant transformation of a plexiform neurofibroma
Most commonly found on the extremities and trunk, and less often on the head and neck
An interesting feature of MPNST is a “divergent differentiation” i.e. the presence of other lines of differentiation, including glandular, cartilaginous, osseous or rhabdomyoblastic morphology
S100+
Characteristics of conjunctival carcinoma
Keratinizing squamous cell carcinoma
Develop from precancerous lesion (Bowden’s disease-squamous cell carcinoma in situ)
Often associated with human papillomavirus (HPV) types 16 and 18
Clinical presentation: Whitish, bulging thickening of the epithelium with an irregular surface
Characteristics of uveal melanoma
Most common primary intra-ocular malignancy of adults
Develops from choroidal melanocytes
Common location” Choroid~18%, Ciliary body ~15%, Iris~5%
Risk factors: Uveal nevus, light skin color, and light color of iris
Clinic: Visual field defects, floaters, and/or photopsia due to tumor-related retineal detachment
Fundoscopy: A pigmented lesion near temporal margin of the optic disk
Histological characteristics of retinoblastoma
Clinical features:
Leukocoria (“cat’s eye pupil”); Strabismus
Progressive loss of vision- due to tumor infiltration into the macula or vitreous body
Sudden loss of vision- due to retineal detachment
Histological characteristics of retinoblastoma
Small blue cells- round with hyperchromatic nuceli, scanty cytoplasm
Rosettes and fleurette
Necrosis; viable tumor around blood vessels
Dystrophic calcification- characteristic
Characteristics of tuberous scelerosis
Characterized by hamartomas (cortical tubers)
Presentation: Seizure (infantile spasms)
Mutation:
TSC1 (encodes hamartin on chromosome 9)
TSC2 (encodes tuberin on chromosome 16)
Skin:
Adenoma sebaceum (angiofibromas)
Hypopigmented macule (ash leaf spot)
Shagreen patches
Visceral cysts: Liver, kidney, pancreas
Retina- Retinal glial hamartomas
Heart-Cardiac rhabdomyomas
Renal-Renal angiomyolipomas
