A plantar fibroma is a benign mass that grows along the plantar fascia, which is the band of connective tissue that supports the arch of the foot. Plantar fibromas are commonly found in the mid-arch region but they can develop anywhere along the bottom surface of the foot.

While not initially painful, plantar fibromas can cause significant discomfort if left untreated.

Causes of plantar fibromas

The exact cause of plantar fibromas is unknown, but there are several factors that could play a role in the development of these growths:

• Trauma: Damage to the plantar fascia can lead to the formation of plantar fibromas. In fact, the development of excess tissue may actually be an aggressive healing response following injury from overuse or trauma (including puncture wounds). 
• Plantar Fasciitis: A common condition among runners, plantar fasciitis causes tightening of the plantar fascia, which can eventually lead to tears in the connective tissue. Plantar fibromas may develop in response to these small tears of the plantar fascia.
• Genetics: Some people are simply predisposed to fibrotic diseases and overdeveloped tissue. 
• Other Conditions: Beta-blockers, anti-seizure medications, and certain supplements may contribute to the development of plantar fibromas following trauma to the plantar fascia.

Plantar fibroma symptoms

Plantar fibromas are easy to recognize; they start as one or more small lumps on the bottom of the feet that feel firm to the touch. The masses can occur in one or both of your feet and may enlarge over time.

Plantar fibromas can develop anywhere along the bottom of your feet and are felt just under the skin. The growths themselves are not usually painful, but as they increase in size, they will start putting pressure on the structures of your feet. This can make walking and standing for long periods very painful.

Treatment of plantar fibromas

Plantar fibromas do not generally go away or decrease in size on their own; treatment is necessary to reduce the discomfort associated with these growths.

Non-invasive treatment of plantar fibromas can include: 

• Change in shoes 
• Orthotics 
• Steroid injections 
• Physical therapy and stretching

While these non-surgical treatments can relieve some of the pain caused by plantar fibromas, they will not cause the growths to disappear. Surgical treatment to remove the growths is sometimes necessary. Consult your physician to learn more about surgical and nonsurgical treatment of plantar fibromas.