11. PATH Tumors Flashcards
The MC location of tumors in adults is supratentorial, more specifically the MC neoplasms are infiltrating astrocytomas (glioblastoma multiforme IV/IV) in the cerebral hemisphere. The most common type of primary CNS lymphoma is large B cell lymphoma. What is the most common location and tumor in children?
Posterior fossa (cerebellum/brainstem) pilocystic (cystic cerebellar) astrocytoma and medulloblastoma (embryonal)
Brain tumors are the 2nd MC malignancy among children, leukemia is the MC. again, location in adults is supratentorial, and in kids it is infratentorial such as cerebellum and brainstem- mc being embryonal-medulloblastoma (seen in younger than 2y/o in post fossa). What in an adult would lead you to think the root cause is a brain tumor?
New onset of SEIZURE in adult
Glioblastoma?
Grade I: low proliferative potential, possibility of cure by resection
Grade II: infiltrative, despite low proliferative potential, likely to recur, some progress to higher grade and have cytological atypia
Grade III: radiation/chemo, will see anaplasia and mitoses
Grade IV: rapid pre and post evolution, fatal outcome with what two things?**
Microvascular proliferation and or necrosis** - how you tell III from IV
What is the most common type of primary brain tumors which include astrocytoma, oligodendrogliomas, and ependymomas which all arise from a glial cell progenitor- all occur in certain regions of the brain with characteristic age distributions and clinical course- glioblastomas typically occur in older adults as a primary new disease?
Gliomas
There are two main categories of astrocytomas- infiltrating and localized and they can be found anywhere in the CNS. Infiltrating astrocytoma (IE GBM IV) account for 80% of US brain tumors and found in cerebral hemispheres mainly, usually affecting 40-70s, there is a grading system: I: doesnt exist II:diffuse astrocytoma, III:anaplastic astrocytoma IV:?
Glioblastoma (malignant)
For gliomas, there are 4 histologic parameters including nuclear atypia, mitoses, microbascular proliferation and necrosis. A grade II will have one parameter, grade III (anaplastic) will have two parameters and grade IV will have?
3 or 4 parameters
With astrocytomas, grade II usually occur in 30-40s, grade III occur in 50s and grave IV occur in 60s… an elderly pt with well differentiated lesion should raise concern of sampling, it should be noted that atrocytomas are usually what type of lesions?
White matter lesions
What type of astrocytoma is a poorly defined grey tumor that vary in size and can appear well demarcated but always infiltrate past their obvious boundary*, may have cystic degeneration, a higher cellular density, and extensive network of GFAP positive astrocytic processes to make a fibrillary background appearance, seen as a gray/translucent/ glassy tumor?
Diffuse Astrocytoma
Genetic patterns of GBM are placed into 1/4 subtypes, Classic subtype is the MC type of primary GBMs and are characterized by PTEN mutations, deletions of chr 10, amplification of EGFR (leads to RTK signaling) and focal deletions of 9p21. What type is the MC type of secondary GBMs characterized by mutations of TP53 and point mutations in IDH1 and IDH2 sometimes overexpression of receptor for PDGFRA leads to inc RTK signaling and sustained proliferation?
Proneural Type
The neural subtype of GBMs is characterized by neuronal markers like NEFL, GABRA1, SYT1, and SLC12A5. What subtype of GBM is characterized by deletions of *NF1 gene on chr17= neurofibromatosis type 1, and there is also overexpression of genes in the TNF/NF-kB pathways?
Mesenchymal Type
Anaplastic astrocytomas are more densely cellular and have a great nuclear pleomorphism with mitotic figures, what term is used for tumors in which the predominant astrocyte shows a brightly eosinophilic cell body with abundant stout processes?
Gemistocytic astrocytoma
Glioblastoma multiforme aka GBM, histologically looks like anasplastic astrocytoma with necrosis and vascular endothelial proliferation which causes tufts of cells to pile up and bulge into the lumen which can form ball like structures called glomeruloid bodies, GBM often occurs in serpentine pattern in areas of hypercellularity, and what is seen which is known as tumor cells collecting along the edges of necrotic regions?
Pseudo-Palisading
Infiltrating astrocytomas well differentiated tumors have a mean survival of 5 years since they are slow growing, higher grade tumors have leaky vessels that allow them to be seen with contrast easier since their blood brain barrier is more permeable- usually 15 month survival for GBM and time is decreased if the tumor is large and nonresectable or they have poor?
performance stats
What astrocytoma is a non-infiltrating grade I/IV, relatively benign and slow growing, occuring in kids and young adults-first two decades of life, seen mainly in the CEREBELLUM* (kids) and sometimes in cerebral hemisphere, often have BRAF and NF1 mutations causing loss of neurofibromin in the tumor, generally well circumscribed?
Pilocytic Astrocytoma I/IV
Pilocytic Astrocytoma I/IV often has biphasic pattern with loose glial with cystic changes and dense piloid tissue (see mix), tumor is seen as hair-like thin long cells with long bipolar processes that are GFAP +, radiology shows a descrete, contrast enhancement, with lack of edema and OFTEN is seen in cerebellum as cystic with a ?
*Mural Nodule on the wall of the cyst
Pilocytic Astrocytoma I/IV tumors are biphasic with loose microcytic and fibrillary areas, there is often an increase in the number of vessels that have thickened walls and vascular cell proliferation, they show limited infiltration of the surrounding brain** so prognosis is good, characteristic findings include eosinophilic granular bodies EGBs and what, which is signal of long standing gliosis?
*Rosenthal Fibers- beaded sausage to cork screw shaped hyaline bodies - bright red on masson trichrome
What is the MC primary brain neoplasm and has two types: 1) primary: occurs later in life with no precursor lesion (EGFR and PTEN), 2)secondary: preceded by lower grade lesion (TP53), IDH1 (R132H mutation associated with a BETTER prognosis) and IDH2- typically seen in younger patients?
Glioblastoma IV/IV
***IDH1 mutation is associated with better outcome
Glioblastoma IV/IV is seen throughout the brain, on imaging will see contrast ring enhancing, and hypodense central necrosis, cells follow fiber tracts and extend well beyond imaging. Glioblastomas MUST have 3 hallmarks including 1) necrosis - serpentine pattern in hypercellular areas 2)pseudopalisading of cells around necrosis 3)?
Vascular/Endothelial Proliferation produced by VEGF due to hypoxia which eventually forms glomeruloid bodies
Glioblastoma IV/IV are often seen crossing the corpus callosum and described as necrotic and hemorrhagic, with endothelial proliferation and pseudopalisading which is cells lining up perpendicular to necrotic areas, the cells are pleomorphic and all different sizes and shapes and the vascular proliferation resembles what?
Glomerulus in the kidney
What makes up 10-15% of all gliomas, primarily seen in adults- cerebral hemispheres, infiltrating gliomas II/IV, seen in 30-50s, patients may have several years of neuro complaints such as seizure, usually seen in white matter, most are well differentiated with a better prognosis?
Oligodendroglioma II/IV
round cell tumor
Oligodendroglioma II/IV - 90% have IDH1 or IDH2 mutations leading to a better prognosis (like astrocytic tumors), 80% have deletion of 1P19Q allowing them to be sensitive to chemo (favorable), they can progress to anaplastic Oligodendroglioma with loss of 9p 10q and mutations in CDKN2A, usually restricted to the cortex, curvilinear or gyriform distribution- well circumscribed with cysts, focal hemorrhage and most importantly***?
CALCIFICATION
Histologically, Oligodendroglioma II/IV has perineuronal satellitosis = tumor cells infiltrating the cerebral cortex collecting around neurons, perivascular aggregation and subpial accumulation of tumor cells, mitotic activity is low or absent, commonly seen perinuclear halos or fried eggs (artifact), and delicate anastomosing capillaries which looks like?
Chicken wire*
What type of Oligodendroglioma are grade III, with a greater cell density, nuclear anaplasia, and detectable mitotic activity and necrosis, vascular hypertrophy see as well, often found in nodules of a grade II tumor, carries a poor prognosis similiar to GBM?
Anaplastic Oligodendroglioma III/IV
What type of tumor most commonly arise next to the ependyma lined ventricular system, including the central canal of the spinal cord, arise IN the ventricular system, often in fourth ventricle- causing obstruction to CSF flow, typically between 0-20years, in adults MC location is spinal cord, they are common tumors in patients with NF type 2?
Ependymomas (II/IV)
Ependymomas II/IV are usually in the 4th ventricle and are discrete, exophytic and enhancing, supratentorial location - cystic and paraventricular-astrocytoma like, NF2 mutation most associated with spinal cord lesion, do NOT have TP53 mutation, grade III: usually supratentorial, mitoses, microvascular proliferation, necrosis and is what variant?
Clear Cell Variant (anaplastic)
Ependymomas II/IV are cellular tumors, with uniform population of cells with round or oval nuclei with ABUNDANT clumped chromatin*, cytoplasm extends to form meshwork producing fibrillary background of projects toward vessels… What are seen and are more diagnostic than perivascular pseudorosettes (tumor cells around vessels with intervening zone consisting of thin ependymal processes directed toward the wall of the vessel)?
Ependymal Rosettes (true rosettes)- have tubular structure with central canal
*GFAP +
What type of rosettes have neuropil in the center and are seen in neuroblastoma, medulloblastoma and PNET?
Homer Wright
What type of rosettes have a tubular lumen in the center and are seen in ependymomas, retinoblastomas, wilm’s and carcinoids?
Flexner - True Rosettes
