Abstract

As a factor of the pathogenesis of neural lesion in LL and the possibility of axonal spread of mycobacterium leprae were studied by means of nerve biopsies. Nerve biopsies were performed with radial cutaneous nerve in one patient and superficial peroneal nerve in the other. Both patients have had a relatively short period of morbid duration and treatment. The results were as follows : 1) The M. leprae bacilli were frequently observed in Schwann cells, macrophages, endothelial cells and perineurial cells. 2) Most of M. leprae were surrounded with electron dense membrane in the cytoplasm of these cells. The multiplication of M. Ieprae induced foamy degeneration of them. 3) Myelin break-down, axonal degeneration and marked fibrosis in nerve lesions were followed by Schwann cell infection. 4) Nerve lesions were conducted by the spread of bacilli via Schwannian passage and vascular dissmination. 5) Intra-axonal presence of the bacilli were not observed in these cases.