The lesions shown in the illustrations are from the forehead of a 77-year-old man (case 1, Figure 1), the temple of an 83-year-old man (case 2, Figure 2), and the clavicle of a 26-year-old woman (case 3, Figure 3). All 3 patients had prior basal cell carcinomas in these locations that had been treated with excision (cases 1 and 2) or photodynamic therapy (case 3). The original tumors were not noted to be pigmented. In these 3 cases, the first sign of early relapse was the presence of brown-gray pigmented foci that revealed ovoid-globular structures (arrows, Figures 1 through 3) on dermoscopic examination. Histologically, the brown-gray structures corresponded to tumoral nests at the dermoepidermal junction (Figure 4). The brown-gray coloration presumably resulted from local increases in melanin caused by recurrent tumor at the dermoepidermal junction. These brown-gray structures may be an important clue for detection of the early relapse of some basal cell carcinomas.
Cuellar F, Vilalta A, Puig S, Palou J, Zaballos P, Malvehy J. Dermoscopy of Early Recurrent Basal Cell Carcinoma. Arch Dermatol. 2008;144(9):1254. doi:10.1001/archderm.144.9.1254