All feet have natural prominences in certain areas. There are extra lumps and bumps that can appear and while these may be normal tissue they can also be due to what are called neoplasms. Neoplasm is a generic term that refers to the new growth of tissue that was no present naturally on the foot before. Because this term is generic, it does not specifically define whether the new tissue is dangerous (like cancer) or not.
Benign neoplasms are those which are not dangerous. This doesn’t mean that they are painless or even that they can stay put without causing issues, but they are not cancerous and do not spread and affect other tissues.
- Fibromas are made up of connective tissue in the body. The most common area of the foot where these are seen is along the arch of the bottom of the foot, in the plantar fascia. In this area, some people are prone to developing these little masses. They can occur as the result of multiple small injuries to this ligament, whereby scar tissue forms in the ligament. These are not always seen as often as they are felt. When walking, especially barefoot, patients who have a fibroma feel that there are knots along the arch of their foot. It may even come to light when having a pedicure or foot massage. When pressure is applied directly in these areas they feel tender. Due to the fact that these masses are a form of scar tissue, they can recur or reform after they are removed. That being said, these lesions don’t always need to be surgically removed. In many cases, custom orthotics with pockets to accommodate these areas will relieve pain. Also, topicals can reduce the size of these lesions making them less painful.
- A lipoma is a benign mass of fatty tissue. Lipomas seen in the feet are most commonly seen in front of the outer ankle bone, in women over the age of 40. Fatty tissue is deposited here, making the ankle look swollen. Unless these fatty masses place pressure on a nerve and cause pain, they are left alone. These masses can recur, though less frequently than fibromas.
- Ganglion cysts
- Another fairly common neoplasm in the feet and ankles are ganglion cysts. These little masses happen as the result of a weakening in either the capsule of a joint or the sheath of a tendon. Think of a weak point in a water balloon. These thinner areas pocket out and fill with synovial fluid (which is a natural lubricant in our body) which normally is present within the joint or within the tendon sheath. These masses have historically been referred to as ‘bible bumps.’ They got this name, as they used to be treated by dropping a heavy book (such as a bible) on the area. This would essentially rupture the cyst and the fluid would be resorbed. However, this is not the standard treatment today. For one, the identity of these masses should be identified by having careful evaluation of the fluid to ensure it is not a malignant lesion mimicking a ganglion cyst. Additionally, if the mass ruptures but the weakening of the capsule or tendon sheath has not been addressed, the mass can recur. Even in instances where these ganglion cysts are surgically removed, it can be difficult to identify and tie off the ‘stalk’ where the fluid is fed into the lesion. This is why ganglion cysts also recur often after removal.
- Mucoid cysts
- Mucoid cysts are very similar to ganglion cysts. However, these occur on the toes near the small joints within them. They can also occur adjacent to nails.
- A granuloma is a mass of inflammatory tissue that typically occurs as the result of some trauma or irritation to an area. In the feet, these most commonly occur in conjunction with an ingrown nail. Sometimes they are associated with infection, though they do not alone indicate that an infection is present. When a toenail encroaches on the skin adjacent to it and causes a small open area to form, inflammatory tissue in the body enters in attempts to heal this area. As the case with many ingrown nails, if the nail is not removed from the equation, the inflammatory tissue continues to deposit until it looks like a beefy red, localized swelling. As blood vessels dilate in these areas and are not well protected, granulomas tend to bleed with the lightest pressure or irritation. Granulomas adjacent to toenails are treated in conjunction with the ingrown nail. The offending, painful border must be removed, the area cleansed and the granuloma is treated with silver nitrate. Silver nitrate is an antiseptic that also cauterizes the inflamed tissue and ensures that this does not remain a source of pain after the procedure. Granulomas recur typically if the same irritation or cause presents again later.
- Verrucae or plantar warts
- Plantar warts are a neoplasm of the skin. They occur as the result of a viral infection. However, not all people who possess this viral infection will develop warts. The reason for this is still not completely understood. Plantar warts at our office are treated with a high-grade compounded acid that is applied every week. The warts resolve in an average of 4 treatments. Because the viral infection in the body remains dormant, recurrences of warts can be a struggle for some.
Malignant neoplasms are masses that have properties that define them as cancerous. These are rarely seen in the foot. However, as they are not expected to be seen in the foot and are typically painless, they can often be mistaken for benign tissue which delays treatment and negatively affects prognosis. There is a malignant counterpart for nearly every benign neoplasm. This is why evaluation by a professional is strongly recommended when you see a new bump or lump – OR if a lump or bump that you have had for a long time starts to change in appearance.
- A fibrosarcoma is a malignant neoplasm that comprises 10% of the sarcomas seen in the foot. These occur most commonly in people aged 30-55. They can occur at any age however. These lesions appear different from the benign fibromas because they are less well defined and seem to be adhered to surrounding structures in the foot. They also tend to grow much larger than benign fibromas and grow at a much faster rate.
- Liposarcomas are lipomas’ malignant counterpart. They occur more commonly in males and primarily between the ages of 40 and 60 years. They are more slowly growing than fibrosarcomas, but this actually can make them more dangerous in a way – as they seem less concerning because of this slow rate.
- Synovial sarcomas
- These masses are similar to ganglion cysts and can often be mistaken as such. They occur more commonly on the top of the foot near tendons and joints. These develop as a painful, tender and enlarging mass. They occur between generally the ages of 15 and 40 years of age and are the most common sarcoma seen in the foot.
- Amelanotic melanoma, basal cell carcinoma, squamous cell carcinoma, metastatic carcinoma and Kaposi’s sarcoma
- These are all different types of cancers that can occur on the foot. They can look similar to a granuloma (benign lesion described above). As benign granulomas usually present near ingrown nails, any lesion that appears on another area of a foot (and looks similar without any history of traumatic injury) could represent one of the above malignant lesions. If a granuloma-appearing lesion has been present for more than 6 months, it is highly suspect for malignancy as well. When the identity of a mass is ever questionable, a biopsy is critical to rule out these malignant lesions.
- Verrucous melanoma
- Verrucous melanoma is a dangerous neoplasm that can be found on the feet and can be mistaken for a common wart. In our office, any wart that has been treated without appropriate improvement or any wart that demonstrates findings suspicious for malignancy is biopsied to evaluate for this condition. Verrucous melanoma is seen more often in women than men and despite its concerning appearance is often painless.
Our office has a variety of ways to biopsy neoplasms. This ensures that any concerning lesion is not left unidentified as this can lead to detrimental consequences. As you can see, some of the benign neoplasms of the foot can appear concerning and worry you that there is a possibility of malignancy or cancer. The same is true of the malignant lesions being more than what they initially appear to be. Our visual exam does not confirm the identity of any lesion, which is why biopsies can be critically important in the treatment of neoplasms.
If you have noticed a change in a mass that you have had for a long time, or if you are noticing a new or growing lesion, evaluation sooner rather than later is the best protocol. Call our office for an appointment today!