Cytodiagnosis of primary neuritic leprosy.

The diagnosis of primary neuritic leprosy (PNL) and its differentiation from other causes of peripheral neuropathy is difficult since acid-fast bacilli (AFB) smears and skin biopsy are negative from anesthetic areas. A biopsy of the involved nerve is the only conclusive method of diagnosis. Such a biopsy may not necessarily be free of complications when a large nerve is involved. However, fine needle aspiration has in this study proved to be a simple technique to demonstrate inflammation granulomas and AFB from these involved nerves in 18 of the 27 cases suspected to have PNL. The validity of the cytological classification into morphological subtypes may have to be supplemented by a large series of studies.