Punch biopsy of a mole on the sole of a patients foot. This skin mark is caused by a proliferation of the melanocytes, the skin cells that produce the pigment melanin. This mole had a fibrillar pattern, where thin parallel lines of pigmentation cross both the ridges and furrows of the skin. This is indicative of a benign (non-cancerous) mole. Moles vary considerably in size and appearance. For a sequence of images showing the mole and punch biopsy see C060/4267 to C060/4271.