A tumor derived from eccrine sweat duct epithelium which may be intra-epidermal (hidro-acanthoma simplex), juxta-epidermal (eccrine poroma) or intradermal (dermal duct tumor). They are comparatively ...
A carcinoma derived from stratified squamous epithelium. It may also occur in sites where glandular or columnar epithelium is normally present. (From Stedman, 25th ed)