About six months ago, the parents of this 1-year-old boy first noticed the lesion on his shoulder. It started as a pinpoint papule but has grown to its current size—at which point, it caught their full attention. Although there are no associated symptoms, the parents request referral to dermatology to clear up the matter.
The child is reportedly healthy in all other respects, maintaining weight as expected, and normally active and reactive to verbal and visual stimuli.
A distinctive orangish brown, ovoid, 8 x 4–mm nodule is located on the child’s right superior shoulder. The lesion has a smooth, soft surface, and there is no tenderness on palpation. No additional lesions are seen elsewhere.
Eye examination reveals normal and symmetrical red reflexes.
What is the diagnosis? 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.