Abstract
A 25-year-old woman presented with a small black speckle on her back which she had since birth. She noted a dark red tumor on the black speckle with surrounding scattered black nodules in March 2008. She had an excisional biopsy of the dark red tumor in August 2008. The tumor size was 7×5×5 mm and the shape was polypoid. Histologically, atypical melanocytes were forming various sizes of nests infiltrating into the dermis. At the adjacent area of the malignant lesion, nevus cells were observed closely. Whereas the lesion being suspected of malignant melanoma revealed 15% positive for MIB-1, the lesion being suspected of pigmented nevus revealed 5% positive for MIB-1. We considered this case as malignant melanoma in association with pigmented nevus. Following, extended resection and sentinel lymph node biopsy were performed in August 2008. The resected sentinel lymph node showed a micrometastasis.[Skin Cancer (Japan) 2010 ; 25 : 324-327]
