What Is a Plantar Fibroma?

A plantar fibroma is a small growth on the arch of your foot. It grows from the plantar fascia, which is the ligament that runs along the bottom of your foot, between your heels and toes. Plantar fibromas are rare and benign (noncancerous). They are often painless, although in some cases they can cause discomfort.

Read on to learn more about plantar fibromas, including their symptoms, cause, diagnosis, and treatment.

Symptoms

Plantar fibromas are often less than an inch in diameter. They may not cause any symptoms.

Symptoms in people who do experience them are mild pain or discomfort on the bottom of the foot. The pain is not directly caused by the plantar fibroma but rather from the location of the growth pressing on nerves or musculoskeletal structures, including bones, muscles, tendons, ligaments, and soft tissue. Pain may increase when you put weight on your foot or wear shoes that increase pressure.

Sometimes plantar fibromas are visible. They may look like a small bulge on the bottom of your foot, almost like a bead, marble, or coin is stuck under the skin.

Causes

It is not known what causes plantar fibromas. However, some people may be predisposed to developing them. Risk factors include:

• Diabetes
• Alcohol use disorder
• Epilepsy
• Assigned male at birth
• Being middle-aged
• Having an immediate relative with a history of plantar fibromas

Diagnosis

Typically, plantar fibromas are diagnosed by a healthcare provider by performing a visual examination and palpation (pressing and feeling the bottom of your foot).

It's possible to misdiagnose plantar fibromas as:

• Malignant sarcoma (cancerous tumor in the connective tissue of the foot)
• Midfoot plantar tear (broken ligaments in the central area of the foot)
• Fractures (broken bones)

Therefore, healthcare providers are urged to perform differential diagnosis, which means ruling out all other possible medical conditions before diagnosis.

In the case of suspected plantar fibroma, imaging tests can differentiate plantar fibroma from other types of growths or lesions. Imaging tests that may be performed include:

• X-ray
• Magnetic resonance imaging (MRI)
• Ultrasound

Treatment

For most people, treatment for plantar fibroma focuses on reducing symptoms rather than treating or removing the growth itself. This is because plantar fibromas are benign, so surgery may carry more risks than letting the plantar fibroma remain.

Some palliative treatments for plantar fibroma include:

• Over-the-counter (OTC) pain medication: These can reduce pain and inflammation.
• Orthotics: These devices are worn inside shoes that support the arch of the foot in a way that reduces pressure on the plantar fibroma. They can be purchased OTC or be custom-made. Orthotics are only recommended if the plantar fibroma is not currently growing or changing size.
• Steroid injections: This may reduce the size of the plantar fibroma and thereby reduce pain when standing or walking.

Surgery

If these more conservative treatments don't resolve pain or impairment, then surgery may be considered to remove the plantar fibroma. Surgery to address plantar fibroma is very rare.

The main surgical techniques to remove plantar fibromas include:

• Local excision: The entire plantar fibroma is cut out from the plantar fascia.
• Wide excision: The entire plantar fibroma and a small amount of surrounding tissue is cut out.
• Complete fasciectomy: The entire plantar fascia, including the plantar fibroma, is cut out. This is the most invasive and least common surgical technique.

The exact technique your surgeon uses will depend on the size and location of your growth. This typically is an outpatient procedure, meaning you will receive anesthesia but be able to go home the same day, assuming there are no complications.

The recovery time for plantar fibroma surgery depends on your individual case. Some questions to ask your surgeon at your preoperative appointment include:

• What should I expect for recovery?
• Will I need any prescribed pain relief?
• Can I use cold or hot packs? When?
• When can I walk or bear weight on my foot?
• Should I keep my foot elevated? For how long?
• Will I be referred to postoperative physical therapy?

Prevention

Unfortunately, there isn't anything you can do to prevent plantar fibromas, but it's still helpful to be aware of the risk factors.

For example, if you have a close relative with plantar fibromas (like a parent) and notice a bulge on the bottom of your own foot, then this health history may help with the diagnostic process.

Summary

Plantar fibromas are growths on the bottom of your foot. They are uncommon, always noncancerous, and can cause pain or discomfort for some people. If minor treatments like OTC pain relievers, orthotics, pain relief creams, or steroid injections do not help symptoms, then excision surgery to remove the growth may be considered.

A Word From Verywell

If you notice new pain when walking, standing, or wearing certain shoes, or if you notice a bulge on the bottom of your foot, contact a healthcare provider. Ruling out other medical conditions is important. If you do get diagnosed with a plantar fibroma, remember that they are noncancerous and a range of treatments exist to relieve any pain or pressure.