What is a xanthoma?
It is an intracellular and dermal deposition of lipid. Often appear like red-yellow papules, nodules, some are associated with lipidemias but some are not
What is the histopathology of xanthoma?
Foam cells (macrophages w/ lipidized cytoplasm in the dermis). In plane xanthomas the foam cells are in the upper dermis but in the nodular, tendinous, and tuberous they are deeper in the dermis
Clinical presentation of eruptive xanthomas?
Numerous red-yellow papules on extensor surfaces, buttocks, intertriginous areas and orally
Triglyceride levels in eruptive xanthoma?
Usually >3000mg/dL
Causes of eruptive xanthoma?
Primary: seen in subtypes with severe hypertriglyceridemia: types I, IV, V
Secondary: obesity, diabetes, alcohol abuse, medication-induced (oral retinoids, protease inhibitors, olanzapine and estrogen replacement)
Clinical presentation of tuberous xanthomas?
Yellow-pink indurated nodules on the elbows and knees usually
What diseases are associated with tuberous xanthoma?
Type II and III hyperlipoproteinemias
What are the clinical characteristics of tendinous xanthomas?
Firm nodules on Achilles tendon and extensor tendons of fingers/hands that develop in the third decade
What disorders are associated with tendinous xanthomas?
Usually seen in type II hyperlipidemia (>type III)
What are the clinical characteristics of plane xanthomas?
These can be localized or diffuse
- Tend to occur on palmar/finger creases (xanthoma striatum palmare) [this is nearly pathognomonic for dysbetalipoproteinemia]
- Can occur in intertriginous areas and web spaces of fingers [usually characteristics of homozygous familial hypercholesterolemia/type II hyperlipidemia]
What is xanthelasma?
It is a plane xanthoma on the eyelid
What disease is xanthelasma associated with?
50% have hyperlipidemia
surgical tx is the best option
What is a verruciform xanthoma?
Benign verrucous plaque that typically occurs in the mouth or genital area
What conditions are verruciform xanthomas associated with?
Not associated with lipid disorders
- Can be associated with CHILD syndrome or any disorder that causes epidermal damage (EB, GVHD, LS&A, pemphigus
What is the histology of verruciform xanthomas?
Looks like a papillomatous epidermal hyperplasia w/ foam cells in the dermal papillae
If a patient has plane xanthomas but normal lipids what should be checked and why?
- SPEP, serum immunofixation
- There is a risk of monoclonal gammopathy caused by a plasma cell dyscrasias like Waldenstrom macroglobulinemia and multiple myeloma.
What endocrine condition can occur with xanthoma disseminatum and why does it occur?
Diabetes insipidus
- Occurs due to xanthomatous infiltration of the pituitary, thus the causation doesn’t go the other way (pituitary tumors causing diabetes insipidus doesn’t increase risk of xanthoma disseminatum
