RESUMO
Patients with leprosy may have only nerve involvement without skin changes. These cases are known as pure neural leprosy and can be seen in 10% of leprosy patients. Most patients have mononeuritic or multiple mononeuritic neuropathy patterns. The isolated lesion of the superficial peroneal nerve is uncommonly seen. We report a patient with involvement of this nerve in which there was no thickening of superficial nerves. The performed nerve biopsy showed inflammatory infiltration, loss of fibers and presence of Mycobacterium leprae. We believe that in prevalent leprosy countries we should take in mind the possibility of isolated pure neural leprosy in some patients without skin lesion. In these cases the diagnosis of leprosy is impossible on clinical grounds and nerve biopsy is mandatory.