Webster's New World Medical Dictionary

xanthoma, diabetic
Xanthoma that is associated
with poorly controlled diabetes mellitus. Treating the
diabetes causes diabetic xanthomas to disappear.
xanthoma, eruptive
Xanthoma that is linked to
lipid disorders and is accompanied by a pink-to-red
raised rash.
xanthoma, planar
A type of xanthoma that is
characterized by flat yellow-to-orange patches or
pimples that cluster together on the skin.
xanthoma disseminatum
A type of xanthoma
from chronically elevated blood fats (cholesterol
and triglycerides) that is characterized by orange-
to-brown nodules on the skin or mucous mem-
branes.
xanthoma tendinosum
Xanthoma that clusters
around tendons and is associated with lipid disor-
ders, including chronically elevated blood choles-
terol levels.
xanthoma tuberosum
Xanthoma that clusters
near joints and is associated with lipid disorders,
cirrhosis of the liver, and thyroid disorders.
xanthomatosis
An accumulation of excess lipids
in the body that is due to disturbance of lipid metab-
olism and marked by the formation of xanthomas.
See also 
xanthoma.
xanthopsia
A form of chromatopsia, a visual
abnormality in which objects look as though they
have been overpainted with an unnatural color. In
xanthopsia, that color is yellow.
xanthosis
Yellowing of the skin without yellowing
of the eyes, as is seen in 
jaundice.
XDR-TB
See 
tuberculosis, extensively drug-
resistant
.
xenotransplantation
Transplantation from one
species to another (for example, from a baboon to
a human).
xero-
Prefix indicating dryness, as in xeroderma
(dry skin).
xeroderma
Abnormally dry skin. Xeroderma
can be caused by a deficiency of vitamin A, systemic
illness (such as hypothyroidism or Sjogren’s syn-
drome), overexposure to sunlight, and medication.
Xeroderma can usually be addressed with the use
of over-the-counter topical preparations.