Plantar Fibromatosis: Understanding Your Pathology Report

Section Editor: Bibianna Purgina MD FRCPC
September 21, 2026

Plantar fibromatosis is a noncancerous growth of fibrous tissue in the sole. It is also called Ledderhose disease. It is a type of superficial fibromatosis, a group of growths that develop just under the skin.

Plantar fibromatosis is not a cancer. It does not spread to other parts of the body or turn into cancer. It develops in the plantar fascia, the thick band of tissue that runs along the sole and supports the arch of the foot.

The same condition can develop in the palm, where it is called palmar fibromatosis or Dupuytren contracture, and in the penis, where it is called penile fibromatosis. About 15% of people with Dupuytren contracture also develop plantar fibromatosis.

This article explains how doctors diagnose plantar fibromatosis and what your pathology report findings mean.

What causes plantar fibromatosis?

The exact cause of plantar fibromatosis is not known. The condition develops when fibroblasts and myofibroblasts, the cells that build and repair connective tissue, multiply within the plantar fascia and produce extra collagen. This makes the tissue thick and firm.

The factors linked to plantar fibromatosis are similar to those linked to the same condition in the hand. They include a family history, diabetes, epilepsy, smoking, and heavy alcohol use. Having the condition in the hand or penis also raises the chance of developing it in the foot.

Repeated foot injury has been suggested as a cause, but this is not settled. Plantar fibromatosis is not contagious and is not related to cancer in the family.

What are the symptoms of plantar fibromatosis?

The usual symptom of plantar fibromatosis is one or more firm lumps in the arch of the foot. The lumps sit along the inner part of the sole and are attached to the deeper tissue rather than to the skin.

Pain with weight-bearing. The lumps often hurt when standing, walking, or running, because body weight presses directly on them.
Difficulty with footwear. Shoes that press on the arch can become uncomfortable.
More than one lump. Several lumps can develop along the same band of tissue, and both feet may be affected.

Unlike the same condition in the hand, plantar fibromatosis usually does not pull the toes out of position. The lumps may stay the same size for years, and some people have no pain.

How is the diagnosis made?

Plantar fibromatosis is usually diagnosed by a doctor during a physical examination of the foot. Ultrasound or MRI may be used to confirm the location of the lump and to rule out other causes of a mass in the foot.

A pathology report is produced when tissue is removed, usually in a procedure called an excision. This is done to relieve pain rather than to make the diagnosis.

What does plantar fibromatosis look like under the microscope?

Under the microscope, plantar fibromatosis is made of long, thin spindle cells set in dense pink collagen. These cells are fibroblasts and myofibroblasts, the same cells found in normal connective tissue. In plantar fibromatosis, they form small rounded groups called nodules within the plantar fascia.

The number of cells changes as the condition ages. Early lesions contain many cells and are described as cellular. Older lesions contain fewer cells and more collagen, and are described as hypocellular. Both appearances are expected.

The cells do not look abnormal, and very few of them are dividing. These features separate plantar fibromatosis from other spindle-cell growths, such as nodular fasciitis. Extra tests such as immunohistochemistry are usually not needed.

Margins

A margin is the edge of tissue cut by the surgeon. Your report may say that the tissue extends to a margin, and for plantar fibromatosis this is expected.

Surgery on the sole aims to relieve pain while protecting the arch and the skin. The surgeon removes the affected tissue rather than a wide area of normal tissue. A positive margin here does not mean the operation failed, although it is one reason the condition can come back.

What is the prognosis?

Plantar fibromatosis is not life-threatening and does not spread. Many people manage well for years without any procedure.

When surgery is performed, the condition comes back in a substantial number of people. Recurrence is reported more often when only the lump is removed and less often when a wider area of the plantar fascia is taken. Surgery on the sole also carries a risk of slow wound healing, scarring that is painful to walk on, and flattening of the arch.

Coming back after treatment does not mean the condition has become cancer. It reflects the tendency of the underlying tissue to thicken again.

What happens after the diagnosis?

Treatment depends on how much pain the lumps cause. Most people start with measures that reduce pressure on the arch.

Padding and orthotics. Custom shoe inserts with a cut-out over the lump take weight off the tender area. This is the usual first step and often controls symptoms.
Steroid injection. An injection into the lump can reduce tenderness and sometimes shrink it, although the lump does not disappear and symptoms may return.
Radiation therapy. Low-dose radiation has been reported to reduce pain and lump size in stubborn cases. It is used more often in Europe than in North America.
Surgery. Removal is usually reserved for people with disabling pain that has not responded to other measures, because the condition often comes back and recovery can be slow.

Treatment is usually provided by a foot and ankle specialist. Collagenase injection, used for the same condition in the hand, does not yet have reliable evidence for the foot.

Questions to ask your doctor

How many lumps are present, and is the other foot affected?
Do I need treatment now, or can this be watched?
Would orthotics or padding help in my case?
Is a steroid injection an option, and how long would it last?
If surgery is considered, how much tissue would be removed?
How likely is the condition to come back after surgery?
What does recovery involve, and how long will it take before I can walk normally?
Does the report say the tissue extended to a margin, and does that matter here?
Should my hands be checked as well?
Who should I see if the lumps return or become painful again?