Excerpt from Juvenile Xanthogranuloma (Nevoxanthoendothelioma)

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Background

Juvenile xanthogranulomas (JXGs) are benign; usually asymptomatic; self-healing; red, yellow, or brown papules and nodules composed of histiocytic cells that predominantly occur in infancy and childhood. Papules or nodules occur in the skin, eyes, and viscera. JXG is the most common form of non–Langerhans cell histiocytosis.

Adamson first reported JXG in the English literature in 1905. He presented a child who developed numerous yellow-white papules on the body in the first 2 weeks of life. He named the entity congenital xanthoma multiplex.

In 1912, McDonagh presented the first case review and renamed the condition nevoxanthoendothelioma (although the condition is not associated with nevi or endothelial cells). In 1954, Helwig and Hackney again retermed it juvenile xanthogranuloma, reflecting its histopathologic appearance. Laurb and Lain first reported JXG with visceral involvement in 1937. Blank et al first described ocular involvement in 1949.

Pathophysiology

The etiology of JXG is not fully known. The papules and nodules of JXG represent collections of differentiated non–Langerhans cell histiocytes. The consensus is that the cells of origin are dermal dendrocytes. As postulated, JXG may be a granulomatous reaction of histiocytes to an unidentified stimulus, possibly of either physical or infectious etiology. Evidence from Kraus et al,¹ however, suggests a possible CD4⁺ plasmacytoid monocyte origin. Inhibition of cellular apoptosis appears to play a minor role in the growth of xanthogranulomas.²

The appearance of giant cells and foamy lipid-laden histiocytes generally occurs late and apparently is a secondary event, possibly in response to cytokine production by histiocytes. Serum lipid levels are normal and remain normal.

Race

JXG occurs in whites approximately 10 times more frequently than in African Americans.

Sex

In childhood, JXG occurs predominately in males (1.4:1). Equal incidence occurs in adult males and females. Multiple cutaneous lesions occur predominantly in males (12:1).

Age

Approximately 35% of cases of JXG occur at birth, with as many as 71% of cases occurring in the first year. The mean age at presentation is 22 months. Most JXGs resolve by age 5 years. Despite the term juvenile in the disease name, 10% of cases manifest in adulthood.

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