Abstract
The patient was a 57-year-old woman. She noticed a brown plaque on her left foot two years before the first visit to our department. The size and color of the plaque had not changed. When she was referred to our department, there was a brown plaque measuring 8.9×11.9×1.0mm in size on the inside of her left heel. The histological finding obtained from the specimens of excisional biopsy showed an increased number of melanocytes in the basal layer of the epidermis and clusters of atypical cells in the lower-dermis. Interestingly, however, there observed a thick fibrotic layer between the above two components was observed. The atypical cells in the lower dermis were S 100 and MART-1 positive but HMB45 negative. Our suspected diagnosis was malignant melanoma, and we performed not only wide local resection of the primary lesion but also sentinel lymph node biopsy. Histopathological examination of the sentinel lymph node revealed several cells which were immunohistochemically positive for MART-1 and HMB45 in the peripheral parenchyma of the node. We finally diagnosed this case as malignant melanoma, and the patient received local injections of interferonβ as an adjuvant therapy. [Skin Cancer (Japan) 2006; 21: 31-35]
