Xanthochromia in CSF is most closely associated with which finding?

• A. Bloody tap during collection
• B. Hemorrhage in the CNS
• C. Bacterial meningitis
• D. Viral meningitis

Answer: (B)

Xanthochromia happens when red blood cells in the CSF break down and bilirubin forms, giving the fluid a yellow color. This pigment buildup takes time, so xanthochromia signals that blood has entered the CSF previously, i.e., a hemorrhagic process within the CNS such as a subarachnoid hemorrhage. That’s why the best answer is CNS hemorrhage.

This finding is not a hallmark of bacterial or viral meningitis, which alter CSF findings through cell counts and chemistry rather than clear pigment changes from blood breakdown. A traumatic tap can produce visibly bloody CSF, but it does not typically cause xanthochromia unless there has been a prior bleed with time for bilirubin to form.