ACUTE BACTERIAL MENINGITIS
( septic meningitis )

✫Gross description
- tan yellow exudate
- Congestive and dilated blood vessels
- Obscures the sulci


✫Microscopic description
- Neutrophils
- Congestive and dilated blood vessels

#MICROSCOPIC

#Diagnosis 👉🏻 acute bacterial meningitis


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Neutrophils infiltration

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Congestive and dilated blood vessels

MENINGIOMA

✫Gross description
- Rounded , circumscribed
- Multiples, grayish white
- whorly cut surface


✫The grades
༄ Grade 1( benign )
Syncytial
- meningothelial cells forming whorls (horning) without visible cell membranes
- eosinophilic cytoplasm

Psammomatous
- Psammoma bodies ( pink calcification )
- meningothelial cells

Fibrous
- cell neoplasm spindle in shape , optical clear and chromatin deposit in the membrane
- clusters of erythrocytes

transitional (mixed)
- has features of syncytial, psammomatous, and fibrous meningiomas

microcystic
- Nucleus plemorphism
- Blood vessels hyalinosis
- Vacuolated cytoplasm

༄ Grade 2 ( local carcinoma )
Chordoid
- myxoid background
- cells arranged in chordss
- Nucleus plemorphism , large mitosis active

Clear cell
- uniforms round nucleus
- blocky collagen (thick and short)
- chicken wire blood vessels

༄ Grade 3 ( Invasive )
Brain papillary
- Nucleus plemorphism, optical clear
- hyperchrmatic, atypia
- Blood vessels
- fingers like projection

Anaplastic
- Nucleus optically clear
- hypercellularity
- Nest
- Necrosis
- Mitosis

#MICROSCOPIC

#Diagnosis 👉🏻 syncytial meningioma


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Whorls of cells

#MICROSCOPIC

#Diagnosis 👉🏻 Psammomatous meningioma


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Meningothelial cells

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Psammoma bodies

#MICROSCOPIC

#Diagnosis 👉🏻  Psammomatous meningioma

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#Diagnosis 👉🏻 transitional meningioma

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Psammoma body

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Fibrous

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Syncytial

#MICROSCOPIC

#Diagnosis 👉🏻 microcystic meningioma

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Blood vessels hyalinosis

#MICROSCOPIC

#Diagnosis 👉🏻 chordoid meningioma


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Myxoid background

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Cell arranged in chords

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Mitosis

#MICROSCOPIC

#Diagnosis 👉🏻 clear cell meningioma


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Blood vessels (chicken wire)

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Blocky collagen

#MICROSCOPIC

#Diagnosis 👉🏻 Brian papillary meningioma

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Blood vessels

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Optically clear Nucleus

#MICROSCOPIC

#Diagnosis 👉🏻  Anaplastic meningioma


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Optically clear Nucleus

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Necrosis

#MICROSCOPIC

#Diagnosis 👉🏻 pilocytic astrocytoma
grade 1

#The_features
- bipolar cells (have processes extending form both ends
- mild hypercellularity
- hairy-like

#MICROSCOPIC

#Diagnosis 👉🏻 diffuse astrocytoma
grade 2


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mitosis

#The_features
- moderate hypercellularity
- mitosis
- little plemorphism
- fibillary (the hair-like processes are grouped to form the fibillary appearance)

#MICROSCOPIC
Grade 3 astrocytoma

- high hypercellularity
- mitosis ( black arrows)

#MICROSCOPIC

#Diagnosis 👉🏻 Grade 4 astrocytoma


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Necrosis

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Angiogenesis ( new blood vessels formation)

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Spindle cells

#The_features
- hyperchromatic nuclei
- plemorphism
- mitosis

- can be differentiated from meningioma by the absence of optically clear nuclei