ULTRASTRUCTURAL MORPHOLOGY AND HISTOCHEMISTRY (ACID PHOSPHATASE) OF THE CUTANEOUS INFILTRATION BY POLYVINYLPYRROLIDONE

SUMMARY.– Two new cases of skin infiltration by polyvinylpyrrolidone are reported. One had 2 types of macroscopic lesion: erythematous plaques, often with yellow pseudo-xanthoniatous papules in the centre, localized round the neckline and the front of the thorax, and small fibromata on the thighs and legs. The other patient had slightly indurated skin in the epigastric region. The ultrastructure of the histiocyte infiltration consisted of dense bodies and vacuoles with various structural variations. The authors stress the extremely generalized nature of this infiltration, affecting all the cell types of the skin, and the presence of intermediary forms linking the dense bodies to the vacuoles. Acid phosphatase activity is present in the dense bodies and certain intermediary vacuoles but absent from the large vacuoles. It is suggested that the dense bodies represent lysosomes with enzyme accumulation which then become loaded with polyvinylpyrrolidone, thus leading to the formation of large vacuoles with no enzyme activity. The well-developed Golgi apparatus in the histiocytes plays a part in the synthesis of lysosomal enzymes.