Abstract
A black spot 3 mm in diameter appeared in a 65-year-old man's right palm in 2001. He underwent an excisional biopsy of the black spot in October, 2004. Histologically, it was diagnosed as a benign pigmented lesion. Five years later, he noticed the pigmented lesion in the same region of the palm.
He consulted our hospital in November, 2013. An excisional operation with the sentinel lymph node biopsy was performed, and it was diagnosed as malignant melanoma. Retrospectively, the pigmented lesion of 10-year ago was considered to be malignant melanoma in situ because dispersion of atypical melanocytes was observed around a sweat duct opening in the excisional biopsy specimen in 2004. [Skin Cancer (Japan) 2014 ; 29 : 309-312]
