Primary EMPD, also known as cutaneous or ectodermal EMPD, is characterized by the expression of sweat gland markers CK7+/CK20-/GCDFP-15+, while secondary EMPD has an endodermal phenotype and is associated with concomitant (primary) carcinoma, most often colorectal (CK7-/CK20+/GCDFP-15-) or urothelial (CK7+/CK20+/GCDFP-15-) [43]. Here, KRT7 is linked to extramammary Paget disease.