Abstract

A 44-year-old Japanese woman had a blue-black nodule on her left leg. The lesion appeared at age 20 and enlarged during her 3rd pregnancy (at the age of 38) with no history of injury. Because there was a suspicion of the nodule being malignant melanoma 8 regional lymph nodes were also removed, and three of which contained black area within the capsule. Histological examination showed the nodule to be common blue nevus with increased number of fusif orm melanin-containing cells lying in parallel with the collagen fibers and also demonstrated the aggregates of pigmented cells similar to dermal melanocytes in the black area of the lymph nodes.