Xanthomas often develop in association with hyperlipidemia. In hyperlipidemic states, the elevated level or abnormal composition of lipoproteins in the blood is thought to result in lipoprotein extravasation and deposition in the skin.[2,4] Both primary hyperlipidemia (arising from genetic disorders of lipid metabolism) and secondary hyperlipidemia (caused by medications or disease states such as diabetes, cholestasis, and nephrotic syndrome) can result in xanthoma formation.[2,5]
Eruptive xanthomas present as a widespread eruption of small red-yellow papules, with a predilection for the hands, buttocks, and extensor surfaces of the extremities. They are associated with hypertriglyceridemia and can be secondary to alcohol abuse; diabetes; obesity; and certain medications, such as oral retinoids, protease inhibitors, olanzapine, prednisone, cyclosporine, and estrogen replacement. Tuberous xanthomas are yellow-pink indurated papulonodules that typically form over the tuberosities of joints, such as at the elbows and knees. Tendinous xanthomas are smooth, firm nodules that involve the Achilles tendon or extensor tendons of the hands, elbows, and knees. Both tuberous xanthomas and tendinous xanthomas are associated with familial hyperlipidemias, particularly types II and III. Verruciform xanthomas, which are small, warty-appearing papules that usually involve the mouth and genitals, are not associated with hyperlipidemia but are thought to result from epithelial lipids released by local trauma.
Plane xanthomas are yellow to orange patches or plaques that most commonly involve the eyelid, neck, upper torso, interdigital areas, and palms. More than 50% of cases of plane xanthomas are associated with a primary or secondary hyperlipidemia. The most commonly encountered type of xanthoma is xanthelasma palpebrarum, a localized plane xanthoma of the eyelid. Patients with xanthelasma have been found to have higher serum levels of total cholesterol and apolipoprotein B (a risk marker of atherosclerosis) than do normal control patients. Other plane xanthomas are pathognomonic of certain hereditary lipid disorders. Xanthomas of the creases of the palm (xanthoma striatum palmare) are seen almost exclusively in familial dysbetalipoproteinemia. Interdigital plane xanthomas, most commonly arising between the thumb and index finger, are strongly indicative of homozygous familial hypercholesterolemia.
Diffuse normolipemic plane xanthomas, as seen in the patient in this case, are widespread large yellow-orange patches or plaques that favor the neck, upper torso, and shoulders. Palpebral involvement can also occur. The clinical significance of diffuse normolipemic plane xanthomas is their association with paraproteinemias, most commonly multiple myeloma. Normolipemic plane xanthomas can also be seen with other hematologic or lymphoproliferative disorders, including monoclonal gammopathy of undetermined significance, Waldenström macroglobulinemia, leukemias (such as chronic myelomonocytic leukemia and chronic myeloid leukemia), B-cell lymphoma, and Castleman disease.[12,13,14,15] The development of xanthomas in association with hematologic disorders is thought to result from the presence of an abnormal serum protein that binds lipoproteins to form complexes that aggregate in the skin.
Because xanthomas are frequently associated with primary and secondary lipid disorders, the initial workup should include a fasting serum lipid panel, measurement of fasting glucose and hemoglobin 1c, and renal and liver function tests. In patients who present with diffuse normolipemic plane xanthomas, a careful evaluation for hematologic and lymphoproliferative disorders should be performed, owing to the association of this subtype with underlying hematologic disorders. Because the development of normolipemic plane xanthomas can precede an associated hematologic disease by months to years, monitoring should be ongoing.[3,13,16] The workup should include a complete blood cell count and serum and urine protein electrophoresis with immunofixation. If a paraproteinemia is detected, referral to a hematologist or an oncologist for further evaluation and management is indicated.
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Cite this: Malgorzata K. Nowakowska, Saira George. Dermatology Case Challenge: Colorful Skin Patches on a Man With Fatigue Who Smokes Cigars - Medscape - Nov 22, 2022.