The SLAT score enables the assessment of 1 or multiple lesions by determining the product of the LDi x SDi (product of the perpendicular diameters or PPD) of all lesions in a given nodal drainage area multiplied by the weight of 1, 2, or 4 as with the mSWAT score. The SPD (sum of the products of the perpendicular diameters) is the sum of the PPDs of all lesions in a given area. The SLAT score is particularly useful for tracking the response of tumors and the weight of 1 and 2 for patch and plaque, respectively, allows capture of a change in height or induration in addition to change in area of lesions prior to complete clearing. By mapping the lesion(s) to the nodal drainage regions as outlined above and in Figure 2, the SLAT score facilitates the determination of the skin classification/staging of the non-MF/non-SS PCLs. It may also prevent overestimation of the size of tumor lesions or change in size of tumor lesions with therapy if assessment was based on percent BSA in mSWAT scoring.