Systemic xanthohistiocytoma: a variant of xanthoma disseminatum?

We present a 66-year-old man who had maculopapular pigmented lesions on the skin of the head, neck and trunk suggesting generalized eruptive histiocytoma (GEH). These lesions had a yellowish centre in a target-like pattern that has not been previously described. The patient suffered from diplopia and had a severe sensorimotor polyneuropathy causing progressive paresis of the limbs. The explorations performed disclosed the presence of specific xanthomatous infiltrates in the skin, lungs, respiratory tract, peripheral nerves and meninges, suggesting xanthoma disseminatum (XD) or juvenile xanthogranuloma. Multiple osteolytic lesions of large bones were also found. The infiltrate was CD68, MAC 387 and factor XIIIa positive and S-100 and CD1 negative. Some cells contained worm-like bodies visible by electron microscopy. Our patient presented clinical and immunohistochemical findings suggestive of GEH, juvenile xanthogranuloma or XD, supporting the idea of a wide spectrum of non-Langerhans cell histiocytosis. These specific target-like xanthomatous lesions seem to be unique for this new variant of XD.