Central Nervous system Flashcards
The central nervous system includes?
Brain
Spinal cord
CSF
Red blood cells in the CSF indicate?
Haemorrhage
CSF showing first neutrophils and later haemosiderin-laden macrophages
Infarction
CSF showing mild cellular increase, lymphocytes and
histiocytes.
Degenerative disorders
CSF showing atypical histiocytes
De-myelinating disorders (eg: MS)
The CSF protein level is elevated and the glucose normal or decreased
Inflammatory and reactive changes of CSF
What is frequently associated with infected ventriculoperineal shunts,
reservoirs for chemotherapeutic agent instillation, parasitic infestation of the CNS
and rarely meningeal carcinomatosis?
CSF eosinophilia
What is an indication of bacterial meningitis?
Neutrophils
What is an indication of viral meningitis?
Lymphocytes and Monocytes
These three pathogens are common causes of bacterial meningitis, especially in
children.
Haemophilus influenzae
Neisseria meningiditis
Streptococcus
pneumoniae
Characterized by a lymphocytic pleocytosis, elevated
protein and decreased glucose levels in the CSF
Tuberculous meningitis
CSF shows:
Blast cells with a very high N/C ratio are usually seen.
The nucleus can be round or convoluted and irregular, and takes up most of the
cell and only a moderate rim of cytoplasm is seen around it.
Neoplastic lesions
Increased numbers of immature blast cells are seen.
The cells are larger than normal lymphocytes and have a higher N/C ratio.
The nuclei vary in size and shape.
Nucleoli are visible and some mitotic figures can be seen.
ALL (Acute lymphoblastic leukaemia)
A monotonous pattern of well-differentiated lymphocytes is seen.
A monotonous pattern on a CSF is abnormal and usually points to malignancy.
CLL (Chronic Lymphocytic leukaemia)
The cells vary in size and shape with a high N/C ratio.
The cells may resemble lymphoblasts.
Some cells have granules in the cytoplasm
AML (Acute myeloid leukaemia)
A large number of lymphoid cells are seen with large tumour cells.
These cells are usually from the large B-cell type and have a fairly aggressive
clinical course.
Lymphoma
The most common protozoan infection in brain biopsies
Smears show mature lymphocytes, plasma cells and macrophages amid necrotic
granular or amorphous debris.
Bradyzooites are recognized as large bag-like structures filled with minute darkly
staining particles.
These cysts can be very large and may even eclipse macrophages.
The borders of the bradyzooites can be indistinct so that the encysted parasites
appear as a group of dark small particles mysteriously organised against a
background of debris.
Toxoplasma gondii
Infections usually produce brain abscesses following
haematogenous spread of the organism from the gastrointestinal or hepatic foci.
Entamoeba histolytica
Smears only show mild increase in cellularity and pleomorphism.
Cytological preparations are relatively sparse with a fibrillary background
punctuated by oval nuclei
Low grade Astrocytoma
Smears show greater cellularity in a retained fibrillary background, marked nuclear
pleomorphism and vascular proliferation, mitotic activity and gemistocytic
astrocytes.
Anaplastic Astrocytoma
Cells range from small with scant cytoplasm and hyperchromatic nuclei, to larger cells with pleomorphic nuclei and sufficiently abundant cytoplasm to justify the designation gemistocytic, to indescribably grotesque large bizarre cells.
The cytologic preparation is cellular and retains a fibrillary background.
Pleomorphic tumour cells appear ensnared in this background and may
accumulate near thickened clumps of proliferated vascular channels.
Necrotic debris is often present in variable amounts
Glioblastoma multiforme (high grade glioma)
Contains cells with clear cytoplasm, distinct cell
borders, and small round to oval hyperchromatic nuclei.
Fields of these “fried egg” cells are perforated by small thin-walled vessels and
are punctuated by flecks of calcium.
Oligodendroglioma
High cellularity, vigorous mitotic activity,
and focal necrosis.
These tumours contain a small population of small gemistocytic astrocytes called
minigemistocytes.
Scant cytoplasm is present, and it is important to recognize that the “fried egg”
cells are artefacts of delayed fixation and are not seen at intraoperative
consultation.
Thin-walled branching capillaries may be seen in the background
Anaplastic oligodendrogliomas
producing
spaces lined by a layer of ciliated cells connected by tight junctions.
Cells arrange themselves around blood vessels producing a paucinuclear zone filled with fibrillary processes immediately around the vessels.
Cytological preparation reveals blood vessels decorated by dense collars of cells
with large round to oval nuclei with pale chromatin and one to two conspicuous
nucleoli.
The cells space themselves from the vessels to form palisades or rosettes with
the long axis of their oval nuclei orientated orthogonal to the vessel wall.
Cells with cilia are infrequently encountered, but detection of these cells is
diagnostic
Ependymoma