THE TAPE STRIPPING TOLUIDINE BLUE (TSTB) METHOD IN THE DIAGNOSIS OF MALIGNANT-MELANOMA - AN INVESTIGATOR-BLIND STUDY

The cytological investigation of the skin surface with the simple, non-invasive tape-stripping toluidine blue (TSTB) method has been proposed to improve the clinical diagnosis of many dermatological disorders. We carried out an investigator-blind study to estimate the sensitivity and specificity of the procedure for the diagnosis of malignant melanoma. One hundred and fifty pigmented lesions were tested. Positive results were obtained in 22 out of 32 malignant melanomas (sensitivity 68.7%), with three false negatives (two cases of lentigo maligna in premalignant phase and one early melanoma in situ) and seven non-significant findings. Negative results were found in 88 out of 118 non-melanoma conditions (specificity 74.5%), with three false positives (two Spitz's naevi and one dysplastic naevus) and 27 non-significant findings. Thus the TSTB method may be a helpful diagnostic tool, in addition to the ABCDE rule, for the early detection of malignant melanoma.