Epidermal inclusion cysts occur infrequently on the palms and rarely on the soles. They probably arise from traumatic implantation and can be experimentally produced by surgical implantation of epidermis into the dermis. A 14-year-old girl had a plantar epidermal inclusion cyst.
Kenneth E. Greer. Epidermal Inclusion Cyst of the Sole. Arch Dermatol. 1974;109(2):251–252. doi:10.1001/archderm.1974.01630020063017