The Journal of the Arkansas Medical Society, Vol 115, No. 9 Med Journal March 2019 Final 2 | Page 18

CASE REPORT
Eruptive Xanthoma as Presenting
Sign of Hypertriglyceridemia
Yoseph Dalia, BS; 1 Sandra Marchese Johnson, MD
1
Northeast Ohio Medical University, Rootstown, Ohio
Introduction
C
utaneous xanthomas is a broad
term for skin lesions that pres-
ent as yellow nodules, papules,
or plaques. The prevalence of cutaneous
xanthomas is unknown as it has not been well-
documented in the literature. There are multiple
variations of xanthomas, including but not limited
to: plane xanthomas, verruciform xanthomas, tu-
berous xanthomas, tendinous xanthomas, and
eruptive xanthomas.
Planar xanthomas are the most common
form, constituting 95% of all xanthomas. 1 They
are soft plaques that can be found on the neck,
trunk, and eyes. When they appear on the eyes,
they are called xanthelasma. They can occur in
the absence of hyperlipidemias, but their presence
still warrants a metabolic evaluation. 2 Verruciform
xanthomas have a characteristic verrucous ap-
pearance and are commonly found in the oral cav-
ity or anogenital area. This subtype of xanthomas
is unique in that it is not related to a systemic dis-
ease; rather, it is thought to be a result of chronic
immunological reaction. 3 Tuberous xanthomas are
yellow and may be surrounded by erythema. They
can be flat or papular and usually present on the
extensor surfaces of joints. Tendinous xanthomas
are hard, mobile subcutaneous nodules that ap-
pear on the tendons of hands, feet, knees, and
Achilles tendons. Occasionally, depending on the
location, the nodules may be painful. 4
Eruptive xanthomas (EX) are described as a
suddenly appearing inflammatory cluster of red-
yellow papules typically 1-4 mm in size. Eruptive
xanthomas appear more commonly on extensor
surfaces of arms and legs, shoulders, or buttocks,
and less commonly on lips, eyelids, or ears. 5 There
have also been cases described in the literature of
EX appearing along lines of trauma, which is known
as the “Koebner phenomenon.” 6,7 Patients may
also have ophthalmic involvement such as lipemia
retinalis, salmon-colored retina with creamy white
retinal vessels. 8 EX is predominately present in pa-
tients with very high concentrations of triglycerides,
often greater than 2,000mg/dl, or uncontrolled dia-
betes mellitus. 5,6,9,10,11 Inherited dyslipidemias that
result in hypertriglyceridemia include lipoprotein
lipase deficiency, apolipoprotein C-II deficiency,
or hepatic overproduction of very-low-density-
lipoproteins. 12 Occasionally, it may even be the first
sign of these systemic diseases. 13
The pathogenesis of cutaneous xanthomas
and its relation to hyperlipidemia can be explained
by the metabolism of dietary cholesterol and fat.
Lipid levels in the blood are determined by mea-
suring lipoproteins and triglycerides. Absorption of
fat and cholesterol occurs in the small intestine.
Next, they are enzymatically digested and reas-
sembled into particles called chylomicrons con-
taining triglycerides and cholesterol. As chylomi-
crons are transported in the blood, they are broken
down by an enzyme, lipoprotein lipase, found on
the endothelial cells of capillaries. This process
forms free fatty acids and chylomicron remnants.
Free fatty acids will later be reconstituted into tri-
glycerides at peripheral tissues, while chylomicron
remnants return to the liver where they are used
in metabolism.
The liver exports very-low-density lipopro-
teins (VLDL), which serve to deliver triglycerides
and cholesterol to peripheral tissues. In the blood,
VLDLs are enzymatically degraded into low-den-
sity lipoproteins (LDL) and free fatty acids (14).
In states of chronically elevated lipids, LDLs leak
through capillaries and become embedded in the
connective tissue of the dermis. Subsequently,
macrophages respond to the LDLs’ presence and
engulf them, forming foam cells. 15 Histopathologic
exam shows macrophages with foamy cytoplasm
and dermal extracellular lipids. 4,12
Primary causes of hyperlipidemia include
inherited genetic disorders that are transmitted
through autosomal dominant and recessive inheri-
> Continued on page 212.
Image 1: yellow-domed papules and tan macules on the lateral back
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VOLUME 115