Peripheral nerve biopsies in the diagnosis of leprosy in Aboriginal patients from the Northern Territory of Australia.

In the 12 years from 1964 to 1976, 171 peripheral nerve biopsies were taken from 81 Aboriginal patients in the Northern Territory of Australia, in whom a diagnosis of leprosy was either known or strongly suspected. Sixty-eight biopsy samples were from 19 patients known to have leprosy, and who were under assessment for nerve grafting, results of which have already been published. We describe here the histopathological findings in the remaining 62 patients, in whom a diagnosis of leprosy was suspected on clinical grounds, backed in many cases by abnormalities of nerve conduction. Forty-one patients (66%) had abnormal histopathological findings in the nerve biopsy sample, 19 (31%) showing definite evidence of leprosy. Several patients with enlarged peripheral nerves, in whom the biopsy findings did not confine leprosy, remain under observation; their future investigation will include lymphocyte transformation tests and testing with refined lepromin, together with repeat nerve biopsy, where ethical and feasible. The clinical and epidemiological data suggest that a previous, and perhaps self-healing, form of leprosy may account for the neurological findings.