[Cutaneous pigmentation caused by amiodarone. Optical and ultrastructural study]. / Pigmentación cutánea por amiodarona. Estudio óptico y ultraestructural.

Thirteen biopsies from 8 patients with amiodarone-induced skin pigmentation were studied. Light microscopy showed that skin pigmentation of these patients was produced by solar elastosis, increase of melanin and accumulation of the properly called amiodarone pigment in the upper dermis. The degree of solar elastosis and the amount of amiodarone pigment was related to total doses of amiodarone. This pigment was negative for fat stains and positive for Masson-Fontana stain, and had neither birrefringency nor autofluorescence. Ultrastructurally, the granules of amiodarone pigment appeared as membrane-bound granules with a fingerprint-like lamellated structure, which others have related to lipofuscin. We conclude, however, that this pigment may be a metabolite of amiodarone, morphologically and histochemically related to melanin.

[Ultrastructural aspects of juvenile xanthogranuloma]. / Aspectos ultraestructurales del xantogranuloma juvenil.

An ultrastructural study of a juvenile xanthogranuloma is presented. Foamy histiocytes reveal several vacuoles of irregular profile containing a type of lipid which is not fixed by osmium tetraoxide. There are also myelin figures. Plasmatic membrane shows numerous digit-like foldings related to collagen fibers. Cytoplasm containing few organelles are restricted to a narrow band around the nucleus and delicate trasverse bandings among the vacuoles. Several intranuclear spheroidal corpuscles have been identified in the histiocytes. Genesis of these foamy histiocytes is discussed probably related to a metabolic derangement of an organelle but in no way related to phagocytosis of fragmented polymorphonuclear leukocytes or Lymphocytes.