Xanthomas

Question 1

What is a xanthoma?

Answer 1

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

Question 2

What is the histopathology of xanthoma?

Answer 2

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

Question 3

Clinical presentation of eruptive xanthomas?

Answer 3

Numerous red-yellow papules on extensor surfaces, buttocks, intertriginous areas and orally

Question 4

Triglyceride levels in eruptive xanthoma?

Answer 4

Usually >3000mg/dL

Question 5

Causes of eruptive xanthoma?

Answer 5

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)

Question 6

Clinical presentation of tuberous xanthomas?

Answer 6

Yellow-pink indurated nodules on the elbows and knees usually

Question 7

What diseases are associated with tuberous xanthoma?

Answer 7

Type II and III hyperlipoproteinemias

Question 8

What are the clinical characteristics of tendinous xanthomas?

Answer 8

Firm nodules on Achilles tendon and extensor tendons of fingers/hands that develop in the third decade

Question 9

What disorders are associated with tendinous xanthomas?

Answer 9

Usually seen in type II hyperlipidemia (>type III)

Question 10

What are the clinical characteristics of plane xanthomas?

Answer 10

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]

Question 11

What is xanthelasma?

Answer 11

It is a plane xanthoma on the eyelid

Question 12

What disease is xanthelasma associated with?

Answer 12

50% have hyperlipidemia

surgical tx is the best option

Question 13

What is a verruciform xanthoma?

Answer 13

Benign verrucous plaque that typically occurs in the mouth or genital area

Question 14

What conditions are verruciform xanthomas associated with?

Answer 14

Not associated with lipid disorders

• Can be associated with CHILD syndrome or any disorder that causes epidermal damage (EB, GVHD, LS&A, pemphigus

Question 15

What is the histology of verruciform xanthomas?

Answer 15

Looks like a papillomatous epidermal hyperplasia w/ foam cells in the dermal papillae

Question 16

If a patient has plane xanthomas but normal lipids what should be checked and why?

Answer 16

• SPEP, serum immunofixation
• There is a risk of monoclonal gammopathy caused by a plasma cell dyscrasias like Waldenstrom macroglobulinemia and multiple myeloma.

Question 17

What endocrine condition can occur with xanthoma disseminatum and why does it occur?

Answer 17

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