Plantar fibroma (lump or cyst)

Description

If you've noticed a small bump on the bottom of your foot, you may have a plantar fibroma.  This is a thickening of the fascia, the band of tissue that crosses the foot from heel to toe.  One or more prominences can be seen on both feet and hands. Unfortunately, this lesion will not diminish in size or disappear naturally. No definitive cause has been identified for the development of this condition.

Fibroma symptoms

The characteristic sign of a plantar fibroma is the presence of a lump in the arch that is firm to the touch. This lump may remain the same size, increase in size over time, or additional fibroids may develop.

Fibroids are not necessarily painful, and most people experience no symptoms. When pain does occur, it is often caused by wearing shoes pushing against the bump in the arch. Pain can also occur when walking barefoot.

Diagnosis

To diagnose a plantar fibroma, podiatrist Dr. Cantin-Langlois will examine and palpate the affected area. This manipulation may cause pain that extends to the toes. Ultrasound, magnetic resonance imaging and biopsy can help in the evaluation and diagnosis.

Treatments

Conservative treatments can reduce pain but will not eliminate the mass itself. Several options are available:

Injecting corticosteroids into the mass may help to reduce it and thus relieve the pain that occurs when walking. This reduction may be only temporary, and the fibroid may slowly return to its original size.

If the fibroid is stable, meaning it doesn't change size, custom-made foot orthoses can relieve pain by distributing the patient's weight away from the fibroid.

When the mass grows, pain increases and no improvement in symptoms is noted with conservative treatments, the podiatrist will need to consider foot surgery to remove the fibroid. Surgical removal of a plantar fibroma may result in flattening of the arch or development of hammertoes. Orthoses can be prescribed to avoid these problems in the post-operative period.  Because of the high risk of recurrence in cases of fibroma, ongoing follow-up with the podiatrist performing the foot surgery is recommended.