Classification
Arachnoid cysts can be found on the brain, or on the spine. Intracranial arachnoid cysts usually occur adjacent to the arachnoidal cistern. Spinal arachnoid cysts may be extradural, intradural, or perineural and tend to present with signs and symptoms indicative of a radiculopathy.
Arachnoid cysts may also be classified as primary (congenital) or secondary (acquired) and have been reported in humans, cats, and dogs
Arachnoid cysts can be relatively asymptomatic or present with insidious symptoms; for this reason, diagnosis is often delayed.
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