Epidermotropic metastatic melanoma. Are the current histologic criteria adequate to differentiate primary from metastatic melanoma?

A case is reported of a patient with a lentiginous acral melanoma of the heel that was excised and recurred 3 years later at the margin of the previous scar. After another 3 years, a group of five small lesions appeared in the thigh that were considered to be junctional and epidermotropic metastases. The authors question the current histologic criteria for differentiating junctional and epidermotropic metastases of previous melanomas from multiple primary melanomas. It is concluded that the clinical history is of primary importance in reaching a correct diagnosis; histologic studies are not sufficient.