Background: Juvenile xanthogranuloma is a rare non-Langerhans cell histiocytosis that could occasionally produce diffuse systemic disease in young children, but associated posterior uveal lesions are very uncommon.
Methods: Case report of an 8-month-old boy with macrocephaly who presented with chronic subdural haematoma and intracranial hypertension. A combination of nodular skin lesions and bilateral yellowish choroidal infiltration with limited retinal involvement suggested juvenile xanthogranuloma.
Results: The diagnosis was confirmed by a skin biopsy, and oral corticosteroid therapy was introduced. Progression of the disease to involve an anterior uveitis with hypopyon and numerous other systemic lesions, including the central nervous system, lung, liver, spleen, kidney and testis, was also suggestive of Letterer-Siwe disease. Histiocytes were negative for Langerhans cell markers (S-100 and CD1a) and positive for macrophage marker (CD68). Electron microscopy failed to show Birbeck granules. Ocular lesions regressed under prolonged corticosteroid treatment, but resurgence of the other lesions required chemotherapy with vinblastine.
Conclusion: In this atypical systemic variant of juvenile xanthogranuloma with bilateral uveal involvement, the immunohistochemical and ultrastructural findings were crucial in distinguishing juvenile xanthogranuloma from Langerhans cell histiocytosis.