To the editor Histiocytoses are a group of proliferative disorders which can be further subdivided into Langerhans cell histiocytoses and non-Langerhans cell histiocytoses (NLCH). The biopsy specimen reveals basal layer hyperpigmentation and dilated dermal vessels surrounded by mild inflammatory infiltrates (haematoxylin-eosin, original magnification ×40) (b). A 4-mm punch biopsy specimen taken from one of the papules of the trunk revealed basal layer hyperpigmentation and dilated dermal vessels surrounded by mild inflammatory infiltrates, composed primarily by mastocytes. [Extracted from the article]