Table 14. . Guitera's two-step method for the diagnosis of basal cell carcinomas and melanoma.

Step	Description	Features
Step 1.	Determine if the lesion is a basal cell carcinoma	Positive features 1. Polarized elongation 2. Telangiectasia and convoluted vessels 3. Horizontal clefting 4. Basaloid nodules Negative features 1. Cerebriform nests 2. Nonvisible papillae 3. Epidermal disarray
Step 2.	Determine if the lesion is a melanoma	1. Cerebriform nests 2. Atypical cobblestone pattern with small nucleated cells 3. Epidermal disarray 4. Pagetoid cells 5. No broadened interpapillary space 6. No dense nests