Plantar Fibroma
Foot & Ankle Care of Colorado
A plantar fibroma is a fibrous knot or nodule located in the arch of the foot, embedded within the plantar fascia—a band of tissue that stretches from the heel to the toes on the underside of the foot. This condition can develop in one or both feet, is benign (nonmalignant), and typically does not resolve or decrease in size without treatment. While definitive causes for plantar fibroma have not been clearly identified, several treatment options are available for managing this condition.
Causes of Plantar Fibroma
There’s no clear reason people develop plantar fibromas or plantar fibromatosis. They appear without a known cause, and can affect anyone.
Plantar Fibroma Symptoms
The most common symptom of a plantar fibroma is pain on the bottom of your foot, usually in the arch. You’ll likely notice this pain for the first time when wearing shoes that put pressure on the plantar fibroma under your skin.
Depending on how big it is, a plantar fibroma can cause pressure on your foot. It might feel like there’s a stone in your shoe, but when you try to shake it out, there’s nothing there.
You might be able to see the plantar fibroma. It might look like there’s a tiny marble — less than an inch across — embedded in your skin. The skin on your foot’s arch will curve out around it, or slightly bulge in a way that’s unusual for the shape of your foot.
Plantar Fibroma Diagnoses
To diagnose a plantar fibroma, the foot and ankle surgeon will examine the foot and press on the affected area. Sometimes this can produce pain that extends down to the toes. An MRI or biopsy may be performed to further evaluate the lump and aid in diagnosis.
Nonsurgical Treatments
Nonsurgical treatment may help relieve the pain of a plantar fibroma, although it will not make the mass disappear. The foot and ankle surgeon may select one or more of the following nonsurgical options:
- Steroid injections. Injecting corticosteroid medication into the mass may help shrink it and thereby relieve the pain that occurs when walking. This reduction may only be temporary and the fibroma could slowly return to its original size.
- Orthotic devices. If the fibroma is stable, meaning it is not changing in size, custom orthotic devices (shoe inserts) may relieve the pain by distributing the patient’s weight away from the fibroma.
- Physical therapy. The pain is sometimes treated through physical therapy methods that deliver anti-inflammatory medication into the fibroma without the need for injection.
When Is Surgery Needed?
Surgical treatment to remove the fibroma is considered if the patient continues to experience pain following nonsurgical approaches. Surgical removal of a plantar fibroma may result in a flattening of the arch or development of hammertoes. Orthotic devices may be prescribed to provide support to the foot. Due to the high incidence of recurrence with this condition, continued follow-up with the foot and ankle surgeon is recommended.
