Sonia Jain, AP Jain

Wardha, Maharashtra

Introduction

Xanthomatosis is a cutaneous manifestation of lipidosis in which the plasma lipoproteins and free fatty acids are changed quantitatively and there is accumulation of lipids in large foam cells in the tissues.1 It is associated with abnormalities of cholesterol metabolism.2 There are five types of xanthomas based on clinical presentation. We are reporting here a case of tuberous xanthoma, which occurs due to familial heterozygous hypercholesterolemia (type II a) and usually presents as nodules localized to extensor surfaces of elbows, knees, knuckles and buttocks.3 Familial heterozygous hypercholesterolemia occurs as a result of inheritance of single abnormal allele for the low-density lipoprotein (LDL) receptor.3 Fredrickson classified familial hyperlipidemia into five main types based on the changes in plasma lipoprotein spectrum and other associated changes.4

Case Report

A 60-year-old female patient presented with history of gradually enlarging nodules over both hands and elbows since 1 year, not associated with pain or itching. The family history was insignificant and none of the family members including parents had similar lesions. However, they could not be investigated because of their unavailability. On examination, she had an average built with height of 145 cm and weight of 60 kg. Her body mass index (BMI) was 17.4. Her blood pressure was 140/90 mmHg and her other vital parameters were normal. On cutaneous examination, multiple yellowish colored papules and nodules were found on the dorsum of fingers of both hands at interphalangeal joints (Fig. 1) and extensor aspect of both elbows (Fig. 2). Examination of the eyes revealed sclerotic changes in the retinal vessels and arcus cornea. Hair, nail, mucosa as well as palms and soles were normal. Laboratory investigations like complete blood count (CBC), erythrocyte sedimentation rate (ESR), blood sugar, lipid profile and skin biopsy were carried out. She was not taking any medications before coming to the hospital. She was found to have raised blood sugar and lipid levels. Her cholesterol was increased 6-folds (Table 1). Electrocardiogram (ECG), treadmill test (TMT) and echocardiography were done to look for the cardiovascular effects of hypercholesterolemia and they proved to be normal. The chest X-ray was normal, while that of hands and elbows showed multiple soft tissue swellings corresponding to cutaneous lesions and normal underlying bones. Biopsy from one of the nodules showed normal epidermis and aggregates of xanthoma cells separated by fibrocollagenous bundles in the dermis.

Discussion

Xanthomas may be seen either as a primary disorder or secondary to various acquired systemic diseases like hypothyroidism, biliary cirrhosis, diabetes mellitus, nephrotic syndrome, monoclonal gammopathy and intake of drugs like b-blockers, diuretics.5 DM is a common cause of hypertriglyceridemia and the eruptive xanthomas may be the first sign of untreated DM.6 Dyslipidemias in DM usually occur in young insulin-resistant diabetics. Insulin is necessary for the normal clearing action of lipoprotein lipase on triglycerides. In this case too, DM was detected for the first time. The decreased lipoprotein lipase activity in insulin-dependent diabetes results in the accumulation of serum triglycerides, the levels of which are occasionally highly elevated to produce eruptive xanthomas.1 Frequently, the underlying problem is uncontrolled diabetes. Xanthomas occur anywhere on the body, but particularly on the extensor surfaces of the limbs and the buttocks. The papules are discrete and dome-shaped but may coalesce to form plaques and nodules when they are called tuboeruptive. Tuboeruptive lesions occur mainly over the elbows.3 Tuberous xanthomas are found localized to the extensor surface of the elbows, knees, knuckles and buttocks.3 Plane xanthomas typically develop in skin folds, especially in the palmar creases (xanthoma striatum palmare) and on the upper eyelids (xanthelasma palpebrum).3 Eruptive xanthoma variant presents with sudden onset of crops of small, pruritic, red-yellow papules on an erythematous base, most commonly over buttocks, shoulders and extensor surfaces of extremities; may spontaneously resolve over weeks.2 Tendinous xanthomas are asymptomatic, slowly enlarging subcutaneous nodules attached to tendons, ligaments, fascia and periosteum with normal overlying skin.2 Extensor tendons of the hands, feet including Achilles tendons are involved more frequently. Our patient was treated for DM with tablet metformin 500 mg twice-daily and for altered lipid levels with atorvastatin 40 mg and fenofibrate 160 mg once-daily with dietary restrictions of cholesterol and saturated fatty acids.

References

1. Errors in metabolism. In: Andrew’s Diseases of the Skin: Clinical Dermatology. 9th edition, James, Berger, Elston, Odom (Eds.), WB Saunders Company: Philadelphia 2000:p.648-81.
2. Black MM, Gawkrodger DJ, Seymour CA, Weismann K. Metabolic and nutritional disorders. In: Textbook of Dermatology, Champion. 6th edition, Burton, Burns, Breathnach (Eds.), Blackwell-Science: Oxford 1998:p.2577-677.
3. White LE. Xanthomatoses and lipoprotein disorders. In: Fitzpatrick’s Dermatology in General Medicine. 7th edition, Wolff, Goldsmith, Katz, Gilchrest, Paller, Leffell (Eds.), McGraw-Hill: New York, NY 2008:p.1272-80.
4. Mahajan VK, Sharma NL, Sood S. Xanthoma tendinosum and familial hypercholesterolemia. Indian J Dermatology 2003;48(2):116-8.
5. Pandhi D, Grover C, Reddy BS. Type IIa hyperlipoproteinemia manifesting with different types of cutaneous xanthomas. Indian Pediatr 2001;38(5):550-3.
6. Binić I, Janković A. Eruptive xanthomas associated with diabetes mellitus. Chinese Medical Journal 2009;122(17):2074-5.