[Electron microscopic study of nerve, muscle and skin lesions induced by perhexiline maleate (author's transl)].

The pathological findings in four nerves and muscles and in one skin biopsies from four patients treated with perhexiline maleate for angina pectoris are reported. In every case, a muscular denervation atrophy and a decrease in the large diameter myelinated fibers were observed. Only one case showed a decrease of the total number of myelinated fibers, on quantitative studies. The electron microscopic study of each nerve displayed findings consistent with a predominant schwannian degeneration, associated with a few onion bulbs formations and, in two cases, with a mild wallerian degeneration. The most striking finding consisted in the presence of polymorphous membrane-bound inclusions reminding the morphology of lysosomal complex lipids. These structures were very abundant in Schwann cells, but they were seen also in fibrocytes, endothelial and pericytic cells. Similar inclusions were present in the single muscle and skin biopsies studied by electron microscopy. In the muscle, they were seen in muscular cells as well as in endothelial and pericytic cells. In the skin, similar inclusions were observed in endothelial, smooth muscle and sweat gland cells. These inclusions were difficult to identify in one micron thick sections, emphazing the need of ultrastructural study for diagnostic purposes.