CNS Tumors 2025 - Dr Emad Transcription PDF

Part 1 Transcribed by: Ward Reviewed by: Rumaysah ------------------------- he seems like a cool guy i like the dictator vibe  Reads 1st point and subpoints. The incidence for intracranial tumors is more than intraspinal tumors. Remember this! -> Most childhood tumors originate in...

Part 1 Transcribed by: Ward Reviewed by: Rumaysah ------------------------- he seems like a cool guy i like the dictator vibe  Reads 1st point and subpoints. The incidence for intracranial tumors is more than intraspinal tumors. Remember this! -> Most childhood tumors originate in the posterior fossa. -> Most adult tumors originate in the cerebral hemispheres. Reads the whole slide. 2  There are specific features about the CNS: 1. No detectable premalignant lesions, which are usually seen in tumors (carcinomas; epithelial tumors) outside the CNS. 2. Different tumors in different ages; therefore age is very important. 3. Rarely metastasize outside the CNS. *yells at student to close ipad & phone* glad he did this to us too because i actually focused lol Reads 4th point, adds: benign tumors do not mean benign effects. The fact that they are in the CNS causes serious side effects even though they’re ‘benign’. Reads 5th point and subpoints. Many times when there is a recurrence, it appears as a grade III or IV tumor. 3  Reads first point and first subpoint. It is very important to know the radiological terminology: -> Intra-axial: in the CNS. -> Extra-axial: outside the CNS. Reads examples for extra-axial only.  Classification is very, very, very complicated. Q: Classification It is getting even more complicated - why? A: Because we depend on neuropathologists that try to include molecular findings in the tumors. Molecular findings are extremely important, we need to ask for them in order to properly classify them. You don’t need to know all of these, we will talk about the most important ones. Reads the names I’ve highlighted in pink, adds: so these are the cells seen in the gray matter - astrocytes, oligodendrocytes, ependymal cells. Neuronal tumors are tumors that show neuronal differentiation. Reads subtypes. Reads last point and subpoint.  He then moves on to the right column (tumors of cranial and spinal nerves). Reads first 3 subpoints, adds to meningioma: involve meninges that cover the brain. Repeats multiple times that molecular findings are VERY important for treatment & for you as a medical student (and very important for the exam). 5  Big fat X you don’t need to know this yay. Doctor’s notes: Diagnostic Procedures Computed Tomography (CT) Scan ?? Evaluate bony lesions, hemorrhages with enhancement – enhancing tumors ?? May miss smaller parenchymal lesions Magnetic Resonance Imaging (MRI) ?? Structures shown in three planes ?? With and without contrast – enhancing lesions ?? Document smaller parenchymal lesions ?? MRI technology variations MRI angiography – visualization of vascular structures MR spectroscopy – documents chemical composition, brain metabolites, increased choline peak, tumor lactate peak - tumor necrosis diagnostic and prognostic tool Positron Emission Tomography scan (PET scan) ?? F-18 fluorodeoxyglucose (FDG) ?? Measures tissue metabolism ?? Differentiates treatment-related necrosis vs. tumor necrosis Transcription: Reads first 2 subpoints under radiological imaging, adds: ‘and so on’. Biopsy is important for the diagnosis. You cannot treat a patient without tissue diagnosis/histopathology. 7  The gold standard is histopathology diagnosis! 7  Reads orange names. Reads first point (whorls). Skips the other definitions and explains rosettes in the next slide. 8  He reads rosette, perivascular pseudorosette, and neurocytic rosette. Then adds: ‘and so on’.  Reads first 2 points. Gliomas arise from glial cells. Again, many tumors in the CNS are seen in specific ages. Reads grading classifications. -> We NEVER use necrosis and endothelial proliferation (in terms of grading) in any other tumor outside the CNS. Never! -> These 2 are used for very high grade CNS tumors.  Reads 1st point. Glial tumors are ALL positive for GFAP. (Transcriber’s note: In our class, a student mentioned that we learned that GFAP was only specific for astrocytes. He said that this was very wrong and that we should go with his definition). Can be diffuse or localized - very important to know. Can be grade I-IV. Cerebellar astrocytoma - MC in children. Adults - ‘the brain itself’.  Reads first two rows. If the astrocytoma is diffuse, it is automatically grade II. There is an ‘issue’ with grade IV that he will explain. -> Sometimes, we see all features as grade IV astrocytoma. However, with molecular testing we now know whether to call it glioblastoma multiforme or not. -> No molecular findings, but gross microscopic features present = grade IV astrocytoma. -> Molecular findings and gross microscopic features present = glioblastoma.  Pilocytic astrocytoma = localized + grade I + kids + cerebellum. Diffuse astrocytoma = grade II and above + adults (5th decade) + NEVER grade 1 in case of ‘diffused’.  Repeats AGAIN that molecular findings are very important, you need to know this. Reads grade I row, adds: IDH should always be negative. Reads grade II row, adds: IDH should always be positive, with higher cellularity, pleomorphism, rare mitotic activity, Grade III: we see more nuclear atypia, more mitotic activity, and IDH is always positive. Keep in mind that endothelial proliferation and necrosis are NOT seen in grade III, ONLY grade IV. Reads grade IV row. 14  Characteristics (labelled): 1. Cystic spaces 2. Rosenthal fibers 3. Eosinophilic bodies/granules  All glial tumors are GFAP positive. Characteristics: -> Increased cellularity. -> Rare mitotic activity.  Nuclear atypia, pleomorphism, hyperchromatic nuclei, mitotic activity -> grade III. NECROSIS + ENDOTHELIAL PROLIFERATION -> GRADE IV. Millionth time mentioned!!!  Seen in adults in the anterior cerebral hemisphere. Q: How to differentiate between grade 2,3, and 4? A: -> Grade II has more cells, pleomorphism, rare mitotic activity. ->Grade III we see nuclear atypia, mitotic activity but NO necrosis or endothelial proliferation. (you better imprint these 2 on both your retinas). -> Grade IV is the infamous type with necrosis and endothelial proliferation. Talks about glioblastoma and grade IV astrocytoma, mentioned in previous slides notes. Q: What is nuclear atypia? A: Large, hyperchromatic nuclei, irregular borders, high N/C ratio. Pleomorphism means multiple shapes of nuclei.  We don’t use the word anaplastic anymore in terms of grade III. ‘We already went through this’.  Reads 5th to 6th decade point only, skips the rest. AGAIN, necrosis and endothelial proliferation are present in the CT scan.  farasha tumor This can be seen on both hemispheres, showing a butterfly invading both sides of the brain. CSF seeding can be seen in glioblastoma. Rarely metastasizes outside the CNS. Can go to bones and lymph nodes. This is an extremely rare tumor. This is all he says about this slide. He does not read the text.  Reads first point. Always a high grade tumor.  This is a glial tumor seen in young ages, localized in the temporal bone. Presents with seizures. We also see a lot of nuclear atypia. We see what looks like a high grade tumor, but it is just grade II - this is because of the nuclear atypia. We do not see mitotic activity or necrosis. We see abundant reticulin deposits and lipids/adipose.  A picture to show you.  Fried egg appearance. It is a neoplastic process seen in all ages, but predominantly in old age and females. 1p19q is always asked for oligodendroglioma, it is typical molecular finding And it’s for diagnosis and prognosis.  Characteristics: 1. There will be a halo present. 2. Uniform cells. 3. Calcifications. 4. Cerebral hemisphere. 5. It is usually grade II. 6. We usually have typical molecular findings - 1p/19q (previous slide last point) - VERY important and specific for this tumor.  Reads first point. Reads sub points under molecular genetics.  You can have a grade III ependymoma, but it is usually grade II. GFAP is positive in all glial tumors. Reads last point, adds: -> EMA is a marker for epithelial tissues. - any epithelium should be EMA positive. -> Vimentin is positive in any mesenchymal and lymphoid cells. -> S100 positive in any peripheral neuronal cells. The cells are uniform, and we see both rosettes and pseudorosettes.  A- Reads first point and first subpoint. There is a myxoid change and papillary change. ->Myxoid ‘a lot of fluid in the background’. B- Anaplastic ependymoma is a grade III tumor. 29  No need to know yayayay. Bye it’s reem’s turn now 30 - Part 2 - Transcription by: Reem - Review by: Rumaysah ------------------------- - Ependymoma prognosis usually depends on location , age and the grade - Usually, ependymoma are grade 2 tumors(better prognosis) rarely becomes grade 3 tumors - Reads slide 31 - Neuronal tumors are seen in young age and usually present with seizures - Reads types of neuronal tumors - All of these types are low grade tumors - Gangliogliomas are the most common -> we see what looks like a ganglion cell and neurocyte - If the cells are neurocytes we call it central neurocytoma usually its grade 2 / low grade neoplastic tumor -> specific location - Reads last point - It is usually rare to find low grade tumors in the brain – some are pilocytic astrocytoma and other is dysembryoplastic neuroepithelial tumor - Usually presents with seizures , located in temporal lobe 32 - When we say embryonal it means immature cellular proliferation - Usually they are high grade tumors -> embryonal primitive neoplasm - Made up of small hyperchromatic cell proliferation - Most common embryonal neoplasms in brain are medulloblastoma, neuroblastoma and atypical rhabdoid teratoid tumour. - Seen in young age group - All these tumours are high malignant tumours. 33 - Reads first 2 points and paraphrase a lil - Its not very rare it can be seen - Its an example of small round tumor in the brain, very malignant cells , hyperchromatic cells - We see a lot of necrosis and mitotic activity - In medulloblastoma rosettes or psuedorossete can be seen - To summarize Young age , cerebellum, hyperchromatic small cells with rosette mitotic activity - Express neuronal markers then reads them 34 Reads Clinically important to classify tumors based on molecular findings -starts talking about molecular diagnosis of CNS tumors and I’m sure no one wants to read all that 35 - By definition it’s a primitive neoplastic process - Mainly seen in children - Teratoid means that multiple cell origins can be seen ( epithelial, mesenchymal etc) - Highly malignant neoplastic process - Rhabdoid means it looks like a rhabdoid sarcoma/rhabdomyoblast - Reads slide ( he mainly does this for all slides just paraphrases a little) - We always do stain for INI1 protein. 36 - Can be secondary to the brain - However, it can be seen as a primary CNS tumor in immunosuppressed patients - Can also be seen in any age group young , old , or even a horse( horse is by transcriber) ( lol- reviewer) - Most common lymphoma is diffused large B cell lymphoma in the brain - Primary means it originates in brain , secondary means it came from the outside 37 - Germ cell tumors are primary brain tumors seen in young age - The most common one is germinoma - Usually, its seen in the midline, pineal and suprasellar regions - Immature germ cell proliferation - Young age means it can be seen in second decade not CHILDREN - Germinoma and seminoma(testicles) are literally the same ☺ - Can we see metastatic secondary germ cell tumors in the brain ? Yes we can - If we have a neoplastic process somewhere else like the testicles then they can metastasize to the brain 38 - Reads slide - Just remember Neurofibromatosis 2(where we have a loss of chromosome 22) and what It is associated with its important 39 - Reads slides - Just remember that for grade 2 or the atypical meningioma we need to have certain features ( cellularity , small cells , high N/C ratio, pattern less growth or necrosis) - If we see a clear cell or chordoid like chordioma then it’s grade II. - Finally reads last point and starts his rant about molecular testing again - Molecular testing is very important. 40 - Answer to student question : brain tumors are usually slow progressing tumors sometimes we don’t pick them up until late - Meningioma is diagnosed later on because it is slow progressing and is usually picked up as an accidental finding while doing a CT scan 41 SO this is a meningioma 42 -Reads pictures -Psammoma bodies are the concentric calcification -We name the meningioma according to cell morphology 43 -Reads slide - Remember Lung is common in male, breast is common in female - Reads second to last point: if we see one tumor only its most likely primary 44