3. Anatomy and physiology
The brain and spinal cord is covered by three meningeal membranes which
are as follows from outside inward:
1- Dura mater
2- Arachnoid mater
3- Pia mater
Formation of CSF:
Most of the CSF formed by the choroid plexuses through ultrafiltration and
active secretion.
Extrachoroidal sites such as the ependymal lining of the ventricles and the
cerebral subarachnoid space are other source of CSF formation.
4.
5. Total CSF volume
Adults 90-150ML
Neonates 10-60ML
There is constant turnover of CSF with 50-500ml being formed
every 24 hours.
6. Indications for lumbar puncture
Suspected conditions:
Meningitis, encephalitis, syphilis, brain abscess, Subarachnoid or
intracerebral hemorrhage, Acute leukemia or lymphoma with CNS
involvement, spinal cord and brain tumor
Therapy :
Chemotherapy for leukemia and lymphoma. Introduction of
anesthetics , radiographic- contrast media
9. Collection
Collect appropriate volumes of CSF into four sterile syringes.
Screw capped tubes consecutively numbered 1 to 4( at least 01ml
in each syringe)
Take CSF specimen immediately (within 15 minutes) to the
laboratory after collection
10. Divisions of CSF samples
Syringe 01 : Hematology (May be contaminated or contain excess
blood)
Syringe 02 : Microbiology (C/S, gram stain etc)
Syringe 03 : Microbiology (AFB culture, special stain, viral
culture, PCR)
Syringe 04 : Hematology and Biochemistry(Cell count ,albumin,
protein, glucose etc)
11. Gross Examination
The cerebrospinal fluid (CSF) is
( In Normal)
Clear
Colorless
Transparent
In Abnormal :
Hazy, cloudy, turbid, milky, bloody, Xanthochromic
Unclear (may contain increased lipids, proteins, cells, bacteria)
Clots( indicate traumatic tap)
Xanthochromic(Yellowing discoloration of supernatant)
12. Biochemical Examination
Normal Components of CSF:
Albumin : 10-30mg/dl
Glucose : 50-80mg/dl
Total protein : 15-45mg/dl
LDH : 40U/L
15. Normal cytological cells present in CSF
Monocytes
Lymphocytes
Clusters of choroid plexus cells
Clusters of ependymal cells
Different stages of maturation of normoblasts
(accidental puncture of the vertebral body)
16.
17. CSF cytopathology
On Giemsa stain / H& E
In bacterial meningitis ( PMN-leukocytes & Monocytes)
In viral meningitis (MN- leukocytes predominant)
In intracranial shunt/idiopathic meningitis( Eosinophilic
leukocytosis)
Cerebral infarct (Lipophage/macrophages)
22. Malignant Cells in CSF
Metastatic Carcinoma
Leukemia
Lymphomatous involvement of meninges
CNS tumor
23. Characteristics of cancerous cells
Large, variably shaped nuclei
Prominent nucleoli
Many dividing cells
Disorganized arrangement
Variation in size and shape
Loss of normal features
24. Most common brain metastasis
Primary tumors
Lung
Breast
Skin
25. Clumps of tumor cells from a patient with
metastatic oat cell carcinoma of lung
26. Leukemias of Brain
Acute lymphoblastic leukemia(ALL)
Approximately 80% of patients with untreated ALL and 60% of
patients with acute myelogenus leukemia(AML) have leukemic
cells in the CSF at some stages of the disease. Therefore, the CSF
should be examined in all patients with Acute leukemia.
28. Brain tumors
Benign brain tumors don't have cancer cells. They grow
slowly, can often be removed, and rarely spread to the brain tissue
around them. They can cause problems if they press on certain
areas of the brain. Depending on the part of the brain they’re in,
they can be life-threatening.
Malignant brain tumors have cancer cells. Some grow
quickly and others slowly. They can invade healthy brain tissue
nearby. Malignant tumors rarely spread beyond your brain or
spinal cord.
29. Types of Brain Tumors
In adults, the most common types of brain
cancer are:
Astrocytomas. These usually form in the largest part of the brain, the cerebrum. They
start in a common type of star-shaped cell called an astrocyte. They can be any grade. They
often cause seizures or changes in behavior. Astrocytomas usually spread throughout the
brain and blend with other tissue. But not all of these tumors behave the same. Some grow
quickly, and some grow slowly. Not all of them grow into other tissue.
Meningiomas. These are the most common primary brain tumors in adults. They’re most
likely to happen in your 70s or 80s. They start in the meninges, the lining of the brain. They
can be grade 1, 2, or 3. They’re often benign and grow slowly.
Oligodendrogliomas. These form in the cells that make the covering that protects
nerves. They’re usually grade 1, 2, or 3. They usually grow slowly and don't spread.
30. Less common types of brain cancer
include:
Ependymomas. This rare cancer forms in your brain or spinal
cord. It starts in cells that line the ventricles (fluid-filled spaces in the
brain) as well as in the canal that holds the spinal cord and
cerebrospinal fluid (CSF). They can be fast-growing or slow-growing.
If they're fast-growing, they’re called anaplastic ependymoma.
These tumors spread along the CSF but don’t spread into normal brain
tissue. Nearly half of ependymomas are diagnosed in kids under age
3, but they can also affect adults.
Mixed gliomas. These are made up of more than one type of cell.
They can include oligodendrocytes, astrocytes, and ependymal cells.
31. Mixed glial and neuronal tumors. These are made up of glial and
neuronal cells. They tend to affect children and young adults. They
include ganglioglioma, pleomorphic xanthoastrocytoma (PXA), and a
dysembryoplastic neuroepithelial tumor (DNET).