Xanthochromie

Xanthochromie is a term used to describe yellow coloration observed in different contexts within science and medicine. It derives from the Greek xanthos, meaning yellow, and chrōmē, color, and is used descriptively to indicate a yellow hue in tissues, fluids, or materials.

In medical contexts, xanthochromie most commonly refers to the yellow discoloration of cerebrospinal fluid (CSF) caused by bilirubin after the breakdown of red blood cells in the subarachnoid space. It typically develops hours after a hemorrhagic event and can persist for several days. Clinically, CSF xanthochrome is often assessed by spectrophotometry, with a peak around 450 nanometers, and its presence supports the diagnosis of subarachnoid hemorrhage when imaging findings are inconclusive.

In biology, the term is used to describe yellow pigmentation in tissues, organs, or whole organisms, arising from pigments such as xanthophylls and carotenoids. This coloration can be genetic or environmentally influenced (for example, diet or light exposure) and is observed across various groups of animals and plants. Xanthochromic coloration can play roles in camouflage, signaling, or nutritional status and is frequently noted in descriptions of coloration for taxonomy and ecology.

Outside medicine, xanthochromie can also be used descriptively to note yellowish hues in minerals, fossils, or other materials, reflecting the presence of certain pigments or chemical treatments. The term is thus a general descriptor of yellow coloration across disciplines.