Abstract
Dermoscopic parallel-ridge pattern is important in making a diagnosis of malignant melanoma on sole skin. Here, we report a case of lentigo simplex with parallel-ridge pattern, that was probably induced by anti-cancer drugs. A woman in her 30's was under treatment with anti-cancer drugs for a malignant soft tissue tumor. She was referred to our department because of a growing oval pigmented macule on her right sole.
One month later, the size of the macule had increased in size from 5.5×5.5mm to 7.5×5.5mm. Both the color and border of the macule were irregular. Dermoscopic examination showed the macule had a parallel-ridge pattern. Because these dermoscopic and clinical findings suggested that this macule was malignant melanoma, we performed excisional biopsy. Pathological examination showed that the macule was lentigo simplex. We speculated that this macule may have been induced by anti-cancer drugs. [Skin Cancer (Japan) 2006; 21: 359-362]
