Epidermal inclusion cyst of the heel.

An inclusion cyst develops from the introduction of epidermal fragments into a heterotopic location, where it grows through accumulation of epithelial and keratinous debris. This is caused by a combination of increased physical activity and the imposition on the site. Inclusion cysts are seen most frequently in younger and more active patients, rather than in older individuals. This case is unique because the epidermal inclusion cyst occurred on the plantar aspect of the foot of an elderly, sedentary patient who had not sustained any injury to the area.