A cobweb-like formation, also known as a pellicle or a "spider's web clot", may appear in the cerebrospinal fluid (CSF) of individuals with tuberculosis (TB). This phenomenon is primarily due to the very high levels of protein in the CSF, typically ranging from 1 to 8 g/L (1000 to 8000 mg/dL) as referenced.
How High Protein Causes the Cobweb
When CSF is left standing, this unusually high protein content can lead to the formation of a fine clot, resembling a cobweb. This is a characteristic feature sometimes observed in tuberculous meningitis.
Key Characteristics
- Appearance: The clot looks like a faint, spider's web or pellicle.
- Cause: High protein levels in the CSF.
- Significance: Can be an indicator of TB meningitis.
Example
If a patient's CSF sample is left to rest and a delicate, web-like clot forms, this is a strong signal that the protein content is elevated. While it isn’t exclusively seen in TB meningitis, it is a significant feature of the disease to consider.
Summary
In TB, the cobweb appearance in the CSF is a direct result of the exceptionally elevated protein levels, a feature that medical professionals look for when suspecting tuberculous meningitis.
