Forty Nine Flashcards
Where are most CNS tumors located in children? In adults? Which are 3 the most common types of tumors for each group? What is the most common primary CNS tumor overall? What is the most common CNS tumor overall?
Children-Infratentorial (Pilocytic Astrocytoma, Medulloblastoma, ependymoma)
Adults-Supratentorial (Metastasis, astrocytomas (fibrillary, GBM), Meningioma
Glioblastoma most common primary
Metastasis most common overall
What are two differences between CNS tumors and systemic tumors?
CNS
- VERY DIFFICULT (IF NOT IMPOSSIBLE) TO HAVE MARGINS
- RARELY SPREAD OUTSIDE CNS
Systemic
- MARGINS ARE OFTEN OBTAINED
- MALIGNANT TUMORS WITH HIGH
METASTATIC POTENTIAL
What is the grade of a pilocytic astrocytoma? What does that mean? In what population is it most common? Where is it usually located? What will it look like on imaging? Name 3 microscopic characteristics of these tumors.
• LOW GRADE (WHO GRADE I)-Well circumscribed, no mitoses, no pleomorphisms, no vascular proliferation/necrosis
• MOST COMMON IN
PEDIATRIC POPULATION
- COMMON IN CEREBELLUM
- IMAGING: CYSTIC LESION WITH MURAL NODULE
- BIPOLAR CELLS WITH ELONGATED CYTOPLASMIC
PROCESSES (PILOID –HAIR LIKE)
• ROSENTHAL FIBERS: THICK EOSINPHILIC PROCESSES
• ROUND EOSINOPHLIC BODIES (EOSINOPHLIC
GRANULAR BODIES)
What is the grade of a glioblastoma? What microscopic findings give it that grade? What are the two types? How do they differ? What does it look like on imaging? In waht population do they occur in?
- HIGH GRADE (WHO GRADE IV)-
- MITOSES
- PLEOMORPHISM
- PSEUDOPALISADING NECROSIS
- ENDOTHELIAL PROLIFERATION
• PRIMARY VS. SECONDARY:
• Pirimary GBM: DE NOVO
• Secondary GBM: AS RESULT OF PROGRESSION FROM A LOW GRADE ASTROCYTOMA (EXCEPT FROM
PILOCYTIC ASTROCYTOMA)
- RING ENCHANCING MASS IN MRI
- OFTEN CROSS CORPUS CALLOSUM : “BUTTERFLY LESION”
Adults and children
What grade is an oligodendrioma? What population is it most common in? What is its growth like? What microscopic pathologic findings are there? How does genetics affect treatment?
- CAN BE WHO GRADE II OR III (ANAPLASTIC)
- ADULTS (YOUNG AND MIDDLE AGE)
- SLOW GROWING: CALCIFICATIONS
- INFILTRATES OF NEOPLASTIC CELLS WITH ROUND NUCLEI AND
PERINUCLEAR HALOS = “FRIED EGG APPEARANCE”
- DELICATED, BRANCHING CAPILLARIES, “CHICKEN WIRE”
- MOLECULAR GENETICS: 1p 19q co-deletions are associated with better
response to chemotherapy, therefore better prognosis
Where do ependymomas occur in children? In adults? Which is more common? Are they diffuse or circumscribed? What might there grade be? What histological findings are there?
- CHILDREN: FOURTH VENTRICLE
- ADULST: SPINAL CORD
- RELATIVELY WELL CIRCUMSCRIBED
- CAN BE ANAPLASTIC (WHO GRADE III)
HISTOLOGY
“CARROT” SHAPE CELLS WITH ROUND
TO OVAL NUCLEI
- EPENDYMAL ROSETTES
- PERIVASCULAR PSEUDOROSETTES
Compare and contrast pilocytic and diffuse tumors.
Pilocytic
- USUALLY IN CHILDREN
- WELL CIRCUMSCRIBED
- INFRATENTORIAL (CEREBELLUM)
- BETTER PROGNOSIS
Diffuse
- ADULTHOOD
- INFILTRATING GROWTH PATTERN
- SUPRATENTORIAL (MOST
COMMON)
- RECURR OFTEN, AND USUALLY
PROGRESS TO HIGHER GRADE
What is the grade of a choroid plexus tumor? Give an exception of this. Where is it located? What problems does it cause? What does it look like histologically?
- LOW GRADE TUMOR
- INTRAVENTRICULAR MASS
- MAY OVERPRODUCE CSF CAUSING
HYDROCEPHALUS
• RARE MALIGNANT VARIANT, CHOROID
PLEXUS CARCINOMA
• HISTOLOGICALLY RESEMBLES NORMAL
CHOROID PLEXUS
What group of tumors does the medullablastoma belong to? How common are they? In what population? What is there location? What is the prognosis/grade? What is their histology?
- BELONGS TO THE GROUP OF PRIMITIVE NEUROEPITHELIAL TUMORS (PNET)
- MOST COMMON PRIMARY CNS MALIGNANT TUMOR IN CHILDREN
- OCCURS MAINLY IN THE POSTERIOR FOSSA (FOURTH VENTRICLE)
- HIGHLY MALIGNANT BUT RESPOND TO RADIOTHERAPY
- ROUND BLUE CELLS: SCANT (ALMOST NONE) CYTOPLASM
- HYPERCHROMATIC, BLUE, NUCLEI
How common are meningioma? In what population do they occur? What do they arise from? What do they look like grossly? Describe the criteria for their grading. Waht do they look like histologically?
• MOST COMMON NON-GLIAL
NEOPLASM
- MOST COMMON IN FEMALES
- ARISE FROM ARACHNOIDAL CELLS
(MENINGOTHELIAL CELLS)
- EXTRA-AXIAL MASS, USUALLY ATTACHED TO DURA
- CAN BE WHO GRADE I (MOST COMMON), II OR III (CRITERIA FOR GRADE II INCLUDE BRAIN INVASION, AMONG OTHERS)
- DURA INVASION OR BONE : NO CRITERIA FOR HIGH GRADE
- MENINGOTHELIAL CELLS: ARACHNOID CAP CELLS: ORIGIN
- WHORLS AND PSAMMOMA BODIES
What do schwannomas arise from? What is their grading? Which nerve does it most commonly affect? What relation does it have to neurofibromatosis type 2? What genes are involved in NF-2? What histological findings are there?
- BENIGN TUMOR FROM SCHWANN CELLS: CRANIAL AND SPINAL NERVES
- CN VIII MOST COMMON
- COMMON IN NEUROFIBROMATOSIS
TYPE 2 (NF-2):
• BILATERAL CN VIII
SCHWANNOMAS= NF2
- AUTOSOMAL DOMINANT, GENE, MERLIN, CHROMOSOME 22
- CELLULAR AREAS (ANTONI A)
WITH ZONES WHERE NUCLEI
LINE UP IN ROWS (PALISADING
NUCLEI)= VEROCAY BODIES
• LOOSE AREAS: ANTONI B AREAS
Waht are two possible causes of neurofibromas? Where nerves are they commonly seen in? What is the inheritance pattern of neurofibromatosis type 1? What chromosome is involved? What nerves are involved? What do neurofibromas look like histologically?
- CAN BE SPORADIC OR ASSOCIATED TO NEUROFIBROMATOSIS 1
- COMMONLY SEEN IN CUTANEOUS NERVES,BUT ALSO SEEN IN PERIPHERAL NERVES
- AUTOSOMAL DOMINANT
- MULTIPLE NEUROFIBROMAS
- CHROMOSOME 17, GENE NEUROFIBROMIN
- MAY INVOLVED LARGE NERVES
- MIXTURE OF SCHWANN CELLS,
FIBROBLASTS AND ENTRAPPED
PRE-EXISTING AXONS
What do hemangioblastomas arise from? Where is their grading? What is their appearance? What is its pathology? In what population?
- Benign vascular neoplasm
— WHO grade I
— Appearance
— Cherry Red
— Cystic filled with clear fluid
— Attached to the pia (rich vascular supply)
— Pathology
— Two components: prominent
capillary vasculature and stromal cells with vacuolated or lightly eosinophilic cytoplasm
Not in children
How can craniopharyngioma be diagnosed? What findings would do this? What differences exist between different craniopharyngiomas? In different populations? What is its appearance at presentation? What do they look like histologically?
— Imaging studies can strongly suggest the diagnosis of craniopharyngioma. The
radiologic hallmark of a craniopharyngioma is the appearance of a (supra)sellar
calcified cyst. About 80-87% of craniopharyngiomas are calcified and 70-75% are cystic. Calcifications are more common in children (90%) than in adults (50%).
— Craniopharyngioma usually presents as a single large cyst or multiple cysts filledwith a turbid, proteinaceous, brownish yellow material that glitters and sparkles
because of a high content of floating cholesterol crystals.
— Because of its appearance, this material has been compared with machinery oil.
— HISTOLOGY SHOWS SQUAMOUS (MORE COMMO IN CHILDREN) OR BASAL EPITHELIUM
— CELLS PRODUCE A DISTINT TYPE OF KERATIN
— IF TUMOR CELLS ARE LEFT BEHIND, WILL CAUSE RECURRENCES
Where are metastases found in the brain? What are they most common sources? Are they well circumscribed or diffuse? How many are there usually? Hemorrhage is seen with which neoplasms?
• METASTASES TO PARENCHYMA,
DURA, LEPTOMENINGES
• MOST COMMON SOURCES: LUNG,
BREAST, MELANOMA, KIDNEY
- SHARPLY DEMARCATED
- CAN BE SOLITARY OR MULTIPLE (OFTEN)
- HEMORRHAGE IS SEEN WITH MELANOMA, CHORIOCARCINOMA, AMONG OTHERS.
