Juvenile Xanthogranuloma

What juvenile xanthogranuloma looks like

A JXG starts as a pink or red, firm, rounded papule (small bump). Over weeks to months it develops the typical yellow or orange color as fat-laden cells collect in it. Features:

• dome-shaped and smooth, sometimes with tiny visible blood vessels on the surface
• usually 2 to 10 mm, although a "macronodular" type can reach 1 to 2 cm
• single in most children, though some have many, sometimes dozens
• most common on the scalp, face, neck and upper trunk, also on the limbs
• painless and not itchy, though it can ulcerate or bleed if knocked

Over time, lesions flatten, turn brownish and leave a slightly wrinkled, lighter or darker spot or a small dimple.

What causes juvenile xanthogranuloma?

The cause is unknown. JXG is a localized buildup of histiocytes, immune cells that normally help clear debris. It is not an infection, not contagious and not related to cholesterol levels: blood fats are normal, unlike in the xanthomas seen with high cholesterol. Recent research has found genetic changes in the cells of some lesions, which suggests it is a clonal proliferation, but it behaves benignly in almost all children.

Who gets it

• Most lesions appear before 1 year of age, and up to about a fifth are present at birth.
• Boys are affected slightly more often than girls, especially those with many lesions.
• Adults can develop xanthogranulomas, usually a single lesion that does not fade.

Link with neurofibromatosis and leukemia

Children with neurofibromatosis type 1 (NF1) have JXG more often than other children. A rare three-way association between NF1, JXG and juvenile myelomonocytic leukemia (JMML) has been described. The absolute risk of leukemia is low, but a child with JXG and several cafe-au-lait macules should be assessed for NF1 and followed by a pediatrician.

Eye involvement

The eye is the most common site outside the skin, affecting a small minority of children with JXG, mostly those under 2 with multiple skin lesions. The iris is usually involved. Possible signs:

• a yellow-brown or reddish spot on the iris, or one iris a different color from the other
• spontaneous bleeding into the front of the eye (hyphema)
• a red, watery, light-sensitive eye
• raised eye pressure (glaucoma), which can damage vision

Eye JXG can occur without any skin lesions. Treatment with steroid drops, or occasionally injections or surgery, usually controls it. Prompt treatment prevents vision loss. Many specialists recommend an eye examination for children under 2 with multiple skin lesions, while routine screening for a single skin lesion is debated.

Other rare internal involvement

Rarely, JXG appears in the lungs, liver, spleen, brain, bone or muscle, called systemic JXG. It mainly affects babies with many lesions or large lesions at birth. Symptoms depend on the organ and may include an enlarged liver, breathing problems or seizures. Most cases still regress, though some need chemotherapy.

How juvenile xanthogranuloma is diagnosed

A pediatrician or dermatologist can usually diagnose JXG by its look and the child's age. Dermoscopy (a magnified skin exam) often shows a characteristic yellow-orange "setting sun" pattern. A small skin biopsy is done if the diagnosis is unclear. Under the microscope, the lesion contains foamy histiocytes and characteristic Touton giant cells, and stains differentiate it from Langerhans cell histiocytosis, which is treated differently.

Conditions it can be confused with include:

Treatment

Skin JXG does not need treatment because it resolves on its own, usually within 1 to 6 years. Removing it surgically leaves a scar, which is often worse than the mark left by natural fading. Surgery may be chosen for a lesion that is repeatedly irritated, bleeding, or in a cosmetically sensitive place, or when the diagnosis is uncertain.

Eye lesions are managed by a pediatric ophthalmologist. Systemic disease is managed by a pediatric oncologist or histiocytosis specialist.

Outlook

The outlook for skin-only JXG is excellent. Lesions regress and leave at most a small mark. Eye involvement usually responds to treatment when found early. Systemic JXG is rare and usually also has a good outcome, though a few cases are serious.

Frequently asked questions

Does juvenile xanthogranuloma go away?

Yes. Skin lesions usually flatten and fade over 1 to 6 years, sometimes leaving a slightly darker, lighter or wrinkled spot. New lesions may appear for a while before they stop. Adults' lesions are less likely to disappear.

Is juvenile xanthogranuloma cancer?

No. JXG is a benign growth of immune cells. It does not spread like cancer and almost always disappears on its own. A rare association with juvenile myelomonocytic leukemia exists in children who also have neurofibromatosis type 1.

Does my child with JXG need an eye exam?

An eye exam is commonly recommended for children under 2 with more than one JXG, because they have the highest risk of eye involvement. See a doctor promptly for a red eye, a blood-filled front of the eye, or a change in iris color.

Is juvenile xanthogranuloma contagious or hereditary?

It is not contagious and is not usually inherited. It can appear more often in children with neurofibromatosis type 1, which is a genetic condition, so a doctor may look for other signs of NF1.