RESUMO
Normal and pathological human nasal mucous biopsies were used and obtained surgically. Pathological one were taken from cocaine addicted patients who had been using this drug during many years mainly by snorting via. From the clinical point of view all patients presented similar symptoms among which the most common were acute and chronic rhinitis, sneeze and bleeding. All cases include showed evident tissue disorganization that ultrastructurally present partial or total lost of cillia as well as disruption between epithelia and basal lamina. Although, normal tissue was substituted by abundant fibrous tissue explaining why this tissue lost its normal function. All described alterations were analyzed by transmission electron microscope and scanning electron microscope.