While foot problems affect a large portion of the population plantar fibromatosis remains a relatively uncommon diagnosis. It is a somewhat rare condition that occurs when plantar fibromas (non-cancerous/benign tumors) develop on the bottom of the foot within the connective tissues (plantar fascia) that run from the heel to the toe of the foot. These benign tumors are firm, slow growing masses that contain excessive collagen or fibrotic tissue levels. Plantar fibromatosis can develop in one or both feet and usually develops in concert with other issues, such as the use of anti-seizure medication Dilantin, or after damage has occurred to the plantar fascia. The reason for the connection between certain medications and the increased development in plantar fibromatosis has not been established.