Mycobacterium leprae in the striated muscle of tuberculoid leprosy patients

Striated muscle specimens from 24 untreated proved cases of tuberculoid leprosy and five healthy normal individuals were studied histopathologically for the evidence of leprous pathology. Atrophy or damage to the muscle fibre was not observed in any patient. Nineteen (79.16%) cases showed evidence of leprosy in striated muscles. Seventeen (70.83%) cases showed scanty histiocytic infiltrate between the muscle fibres. Thirteen (54.16%) cases had acid fast bacilli mostly inside the muscle. There was no correlation between the location of the bacilli and that of the histiocytes; in two cases, acid fast bacilli were seen without the histocyte. The bacilli were solidly staining and were lying singly in the undamaged muscle. There was no evidence of tuberculosis and, in the Control group, none showed any AFB or infiltrate. The presence of lepra bacilli did not depend upon the location of the muscle. Two of the muscle specimens not underneath the cutaneous lesions also had acid fast bacilli. 21.05% of these cases also showed simultaneous involvement of liver and lymph nodes. These are strong evidences of systemic nature of disease in tuberculoid leprosy as well.