Papular xanthoma associated with angiokeratoma of Fordyce: considerations on the nosography of this rare non-Langerhans cell histiocytoxanthomatosis

BACKGROUND: Papular xanthoma (PX) is a rare normolipidemic non-Langerhans cell histiocytoxanthomatosis affecting both children and adults. OBJECTIVE: We describe an adult case of PX associated with angiokeratoma of Fordyce and review the literature in order to compare and discuss previous reports. METHODS: We studied the clinical, histopathological, immunocytochemical and ultrastructural findings. RESULTS: We report the findings of our case and compare our case with those described in the literature. CONCLUSIONS: Three clinical patterns of PX appeared to emerge in the review of the literature: a self-healing form, a persistent form and a progressive form. The progressive form of PX can be considered the same clinical entity that is also described as progressive nodular histiocytosis.