Tiny Tot, Big Lesion

DISCUSSION

Juvenile xanthogranuloma (JXG) is a rare, benign variant of non-Langerhans cell histiocytosis. This patient’s lesion is typical, but JXG can vary in appearance; some patients present with darker or larger lesions—or multiple lesions.

JXGs are essentially granulomatous tumors that, on histologic examination, display multinucleated giant cells called Touton giant cells. These macrophage-derived foam cells are seen in lesions with high lipid content.

JXG tends to favor the neck, face, and trunk but can appear around or (rarely) inside the eye, typically unilaterally in the iris. Benign in all other respects, ocular JXG lesions can cause spontaneous hyphema, glaucoma, or blindness; they must therefore be dealt with by a specialist. Fortunately, only about 10% of patients display ocular involvement.

,

JXGs can be confused with compound nevi, warts, or Spitz tumors. Therefore, biopsy is often necessary to establish the diagnosis.

TAKE-HOME LEARNING POINTS

• Juvenile xanthogranuloma (JXG) is a rare non-Langerhans cell tumor usually seen on the neck, face, or trunk of children younger than 2.
• The orangish brown, soft appearance of this patient’s papule was typical.
• Although atypical JXG lesions may require shave biopsy to confirm the diagnosis, they typically resolve on their own without treatment.
• When JXG lesions appear in the eye (most commonly in the iris), there is potential for serious complications, including heterochromia, glaucoma, spontaneous hyphema, or even blindness.