A case of pigmented Spitz nevus in a 12-year-old boy is reported. Approximately 3 years previously he noticed a small pigmentation on the right dorsum pedis, andgradually increased in size and elevated.
Physical examination revealed a 13×10mm, dome-shaped, black nodule with irregular margin.
An excisional biopsy specimen was histologically diagnosed as nodular malignant melanoma at that time. A wide excision with skin grafting and right inguinal lymph node dissection were performed.
Recently, we checked clinically and histologically again and requested a fluorescence microscopy of formalin-fixed paraffin-embedded unstained specimen and a DNA distribution histogram.
We put the various reports together and finally made the established diagnosis aspigmented Spitz nevus.
Occasionally, a differentiation of a pigmented Spitz nevus from a malignant melanoma is very difficult.
So, we need more information such as a fluorescent finding and a distribution histogram to avoid a misdiagnosis.
