Bottom of the Foot
There are a number of different causes of lumps and bumps on the bottom of the foot. Working from the toes to the heel:
1. Lumps and Bumps on the Bottom of the Big Toe
A painful lump may be found on the bottom of the big toe. This condition often presents itself as a hard callused area. Sometimes a hard lump may be felt beneath the callused area. The most common cause of this condition is a limitation of movement of the big toe joint while walking. If there is limitation of movement at this joint, then the big toe cannot bend upward as the heel comes off the ground while walking. As a consequence, there is excessive force placed on the bottom of the big toe and an enlargement of the bone in this area will occur secondary to the pressure. Another cause is the presence of an extra bone or piece of cartilage in the area. However, it is the limitation of movement in the big toe joint that causes the area to become enlarged and painful.
People who have diabetes must watch these areas closely. Over time, the excessive pressure can cause this area to break down and ulcerate. One way to check to see if there is a limitation of movement of the big toe joint is to perform the following test. While standing on a flat surface, have another person try to bend the big toe upward. The joint that must move is the joint where the toe attaches to the foot. There is a joint in the middle of the big toe and this is not the one you are checking. If the big toe joint cannot be bent upward then a limitation of motion exists. Testing the movement at the joint without putting weight on the foot will give a false impression as to the available movement at the joint while you are walking. This limitation of movement of the big toe while walking can, over, time create an arthritic condition in the joint. A bony mass may then form on the top of this joint as a result of jamming in the joint. This condition is called hallux limitus or hallux rigidus. Treatment for the painful lesion in the bottom of the big toe joint consists of using functional foot orthosis to correct the functional limitation of the big toe joint motion or may consist of surgical correction of the hallux limitus. Rarely is surgery to remove only the lesion on the bottom of the toe alone, successful, because the cause of the initial problem still exists.
2. Lumps and Bumps in the Ball of the Foot
Painful lumps in the ball of the foot are usually but not always associated with a thickening of the skin or callus. These areas are due to a prominence of the long bone behind the toe called the metatarsal bone. When there is a mal-alignment of these bones, one or more of them may become propionate. When this occurs, the weight-bearing force across the bottom of the foot is disturbed. Weight is not evenly distributed across the ball of the foot, and these areas absorb greater pressure. The excessive pressure often forms a callus or thickening of the skin. People who have diabetes should watch these areas carefully. Over time, they can ulcerate the skin and can become infected. Treatment consists of removing the pressure with pads or using a molded insole or orthotic in the shoes.
Other skin lesions that frequently occur on the bottom of the foot are plantar warts, porokeratoses, and inclusion cysts.
3. Lumps and Bumps in the Arch of the Foot- Plantar Fibromas
Within the arch of the foot, firm, nodular masses may form. These can occur as a single mass or in clusters. They are called plantar fibromas and are a non-cancerous tumor that forms within a ligament in the arch of the foot called the plantar fascia. Frequently, they will slowly enlarge causing pain while walking. Their cause cannot always be determined. Damage to the tendon will cause their occurrence and there is an association with taking the drug Dilantin. In 10% of the cases, patients will also demonstrate similar lumps in the palms of the hands called Dupuytren’s Contracture.Treatment consists of padding the area to reduce pressure. Functional foot orthotics will take the strain off of the plantar fascia ligament and sometimes cause the fibromas to shrink in size. Cortisone injections are of little value and may even stimulate the mass to enlarge or spread. Surgical excision of the mass requires removal of most of the plantar fascia. Simple excision of the mass without removal of the entire ligament generally results in recurrence of the mass. Whenever surgery is contemplated, the patient should wear a functional foot orthotic following the surgery. The orthotic helps to accommodate for the loss of the plantar fascia and its effect on foot function.
Inside of the Foot
There are many different causes of lumps and bumps on the inside of the foot. Starting from the big toe and working back to the heel:
A swelling along the margin of the big toenail is likely to be due to the formation of an ingrown toenail. At times this swelling can produce open, weeping flesh. Treatment consists of removing the ingrown toenail.
A swelling often associated with a hard, callused area may form on the side of the big toe. This is due to an enlargement of the bone in this area. It is usually associated with a deviation at the joint in the big toe. Treatment consists of using a functional foot orthotic to redirect the pressure from the area. Surgical removal of the underlying bony prominence or surgical straightening of the toe may be recommended. People who have diabetes must watch this area because over time the excessive pressure to the area from walking can cause the skin beneath the callused area to break down forming an ulceration that can become infected. Left untreated, the bone can become infected and in severe cases amputation of the toe may be necessary.
Another area on the big toe, which can demonstrate a lump or bump, is the top outside portion of the toe at the level of the joint in the toe. This is usually seen in association with a contracture of the big toe making the joint more prominent. This prominence can become irritated due to shoe pressure. The condition is called a Hallux hammertoe. The word Hallux is the medical term for the big toe. If the deformity is flexible and the toe can be manually straightened, the condition can be corrected by a simple surgery that releases the tendon in the bottom of the toe. If the condition is rigid and the toe cannot be manually straightened, then a fusion of the joint may be necessary. Treatment should also include determining what caused the condition. Quite often it is due to some underlying functional problem in the foot and treatment of this condition with a functional foot orthotic should be considered. Other causes of a hallux hammertoe are previous surgery in the area, nerve damage or a neurological condition.
A painful lump may also be found on the bottom of the big toe. This condition often presents as a hard callused area. Sometimes a hard lump may be felt beneath the callused area. The most common cause of this condition is a limitation of movement at the big toe joint while walking. If there is limitation of movement at this joint, then the big toe cannot bend upward as the heel comes off the ground while walking. As a consequence, there is excessive force placed on the bottom of the big toe and an enlargement of the bone in this area will occur secondary to the pressure. Another cause is the presence of an extra bone or piece of cartilage in the area. However, it is the limitation of movement in the big toe joint that causes the area to become enlarged and painful. People who have diabetes must watch these areas closely. Over time, the excessive pressure can cause this area to break down and ulcerate. As in the previous condition this can lead to infection and possible amputation. One way to check to see if there is a limitation of movement of the big toe joint is to perform the following test. While standing on a flat surface have another person try to bend the big toe upward. The joint that must move is the joint where the toe attaches to the foot. There is a joint in the middle of the big toe and this is not the one you are checking. If the big toe joint cannot be bent upward then a limitation of motion exists. Testing the movement at the joint without putting weight on the foot will give a false impression as to the available movement at the joint while you are walking. The limitation of movement of the big toe while walking can, over time create an arthritic condition in the joint. A bony mass may then form on the top of this joint as a result of jamming in the joint. This condition is called hallux limitus or hallux rigidus. Treatment for the painful lesion in the bottom of the big toe joint consists of using functional foot orthosis to correct the functional limitation of the big toe joint motion or may consist of surgical correction of the hallux limitus. Rarely is surgery to remove only the lesion on the bottom of the toe alone successful, because the cause of the initial problem still exists.
Yet another area of bony prominence about the big toe joint is on the outside of the joint. The most common cause of this condition is called hallux abductovalgus or bunion. This is a common condition associated with deviation of the big toe towards the second toe. Treatment consists of padding the area to reduce shoe pressure, bigger shoes, orthotics and surgery. A sudden onset of pain in the area with or without a bunion may be due to gout. Gout is a metabolic condition that results in an elevation of the uric acid in the blood stream. Once the uric acid level reaches a certain point it will crystallize and leave the blood stream and deposit itself in a joint or other soft tissue location. Gout rarely occurs in women until after menopause or if they have had a hysterectomy. A sudden onset of pain in this area in women is usually associated with the formation of a bursa secondary to wearing a tight shoe. Treatment consists of wearing looser fitting shoes and taking an oral anti-inflammatory medication. Occasionally, a cortisone injection may be advised.
Moving back towards the heel, another area of a common lump or bump is just in front of the weight-bearing portion of the heel. This prominence is usually a hard bony mass that protrudes outward. It is due to a bony enlargement of the Navicular bone. Some people have a natural enlargement in this area while other people have an extra bone in this area. This condition is often referred to as Os Navicularis. This condition is often associated with a flat foot deformity. A very powerful tendon from a muscle in the leg called the posterior tibial tendon partially attaches into this area. If the navicular bone is naturally enlarged or there is a second bone present then the tendon dose not function properly and cannot support the arch of the foot adequately. Over time, this will cause a weakening of the tendon causing an entire collapse of the arch of the foot. This condition called Posterior Tibial Tendon Dysfunction is a very serious condition that should be treated promptly and aggressively. The bony prominence of the navicular bone may cause secondary pressure in shoes resulting in pain. Treatment of the prominence of the navicular bone consists of padding to reduce shoe pressure, functional foot orthosis to treat the associated flat foot deformity and the possible onset of posterior tibial tendon dysfunction, or surgery. Following any surgical intervention in this area, the patient should be placed in a functional foot orthosis. The surgical removal of the bony prominence does not correct a flat foot or prevent the occurrence of posterior tibial tendon dysfunction.
Outside of the Foot
There are a few causes of lumps, bumps or prominence on the outside of the foot. Some of these are just normal anatomy; others are due to abnormal processes. Starting from the fifth toe and working back to the heel:
A common prominence on the fifth toe is due to the formation of a hammertoe. A hammertoe is a structural deformity of the fifth toe causing the joint in the toe to become propionate. Pressure from shoes will cause a thickening of the skin. On occasion, this can become very painful making it difficult to wear a closed shoe. Treatment consists of trimming the thick skin or padding the area to reduce the pressure from the shoe. At times surgical strengthening of the toe is necessary.
Just behind the fifth toe, at the joint where the toe connects to the foot, a prominence can develop. This is called a Tailors bunion. It is caused by the abnormal function of the foot and can be slowly progressive. Some people naturally have an enlargement in this area. Shoe pressure can make the area painful and at times cause a bursa to form. A bursa is a sack of inflamed tissue that occurs over a bony prominence in response to excessive pressure or friction. The bursa is spongy to the touch and can be very painful. The bursa can be treated with cortisone injections to reduce the swelling and inflammation. Padding the area is also useful to reduce the pressure from the shoes. Selecting the correct shoe can also be helpful. Surgical correction of the tailor’s bunion is a common procedure to reduce the prominence and the pain associated with it. A rare occurrence of gout can also occur in this area. This condition usually presents with a sudden onset of pain and swelling in the area.
Further down, along the side of the foot another bony prominence can observed. This area is the base of the long bone (metatarsal bone) behind the fifth toe called the styloid process of the fifth metatarsal. In children this area has the growth plate to the bone. Injury to the area can cause the area to become enlarged. X-rays will show an open growth plate until the age of 12 – 14. If there has been an injury to this area in a child with an open growth plate, caution must be taken because of the possibility of injury to the growth plate. A very powerful tendon also attaches into this area of the bone. In the event of an ankle sprain this area can become injured as a result of the tendon attempting to prevent the foot from twisting. Pain to the touch at this site indicates either tendon or bone injury, and an x-ray should be taken. A fracture can occur in this area, and if it is displaced or out of alignment then surgery may be required to repair the bone. If the fracture is in good alignment or if the area is just sprained, then a below the knee cast should be applied. It may take six weeks for this injury to heal.
Some people have a natural enlargement of this area. When painful, padding the area to reduce shoe pressure is useful and selecting the correct shoe is also helpful. Rare instances of gout can also occur in this area.
Just behind the area of the styloid and a bit over to the top of the foot there is a spongy, soft area of the foot. This area represents the extensor digatorum muscle. This is the only muscle present on the top of the foot. In some people it can be quite large. Fatty deposits can also occur about the muscle making the area appear larger. On occasion, a ganglion may form. In this instance, the area may enlarge and then shirk and then enlarge again. A MRI is the most useful test to determine if a ganglion is present. If the area is not painful, no treatment is required. If the area is painful and a ganglion has been identified, then treatment might consist of draining the fluid from the ganglion with a needle or surgically removing the ganglion.
Small, soft lumps can be observed around the fat pad of the heel when a person stands. These small, soft bumps are usually found in groups. They are called Piezogenic papules and represent herniations of fat from the heel fat pad. They are rarely painful and no treatment is necessary. Removal of the pziogenic papules should be discouraged. There is no adequate treatment for their removal, and surgery to the area will only make the condition worse.
Another lump seen on the side of the heel is called an inclusion cyst. This lump appears as an elevated, soft mass which is often callused on is surface. These are caused by minor puncture wounds or from prolonged pressure or friction to the area by shoe gear. Surgical excision is often recommended. Padding the area to reduce friction may be of some temporary benefit in painful situations.
Other less common lumps and bumps that can appear on the outside of the foot are lipomas, fibromas, and giant cell tumors. These are non-cancerous tumors that tend to slowly enlarge and have a spongy like consistency. They only present a medical problem if they interfere with the function of a tendon, press excessively on a nearby nerve or cause pain secondary to shoe pressure. Malignant tumors of the foot are exceedingly rare.
Top of the Toes and Foot
There are several different causes of lumps and bumps on the top of the toes and foot. Working from the toes back these are:
1. Muco-Cutaneious Cyst
Small nodular single mass that can form on the top of the toe is called the Muco-Cutaneious Cyst. These occur most frequently at the joint just behind the toenail. These are caused by a weakening of the joint capsule, which allows a swelling to occur. They are firm and rubbery to the touch. Sometimes as the skin thins due to the stretching pressure of the mass it will appear translucent. When the mass is broken or punctured, a thick clear fluid will leak out. If the mass does break open, the area should be kept clean and free of infection. Once the skin heals the mass will reappear.
2. Treatment of Muco-Cutaneious Cysts
Treatment consists of surgical excision. This can be performed in the doctor’s office under a local anesthesia or in an out patient surgery center. The procedure is relatively simple but can pose a problem for the surgeon, as closure of the skin following removal of the mass can be difficult. Often the surgeon will have to create a skin flap to rotate over the hole where the mass was removed. This requires a bit more of an incision than most patients expect. The foot is bandaged in a dry sterile dressing and the sutures remain in place from 7 to 10 days. The area must be kept dry during this period of time and a limitation of activity is advised. Complications associated with the surgery are infection, delays in healing associated with difficulty in surgically closing the wound or excessive activity which can lead to swelling and recurrence of the mass. Draining the mass as a form of treatment is not advised unless the patient is made aware of the likely recurrence. Picking the area open at home or attempting to drain it at home is discouraged. An infection in the area could cause permanent joint damage or bone infection.
3. Hammertoe Deformity
Another prominence on the top of the toes is caused by hammertoe deformity. As the hammertoe forms, the toe cocks up and the joint in the middle of the toe becomes prominent. As the toe rubs on the top of the shoe a callus will form. Treatment consists of padding to reduce pressure or surgical straightening of the toe.
4. Hallux Limitus
A lump can be found just behind the toe at the joint where the toe attaches to the foot. This is due to a prominence of the head of the metatarsal bone. It indicates that there is an alignment problem with the bones in the ball of the foot. The area may or may not cause a problem. If the lump is behind the big toe joint, it is a sign of a progressive arthritis of the joint. The condition is called Hallux limitus or degenerative arthritis. Treatment consists of orthotics to improve the function of the joint and/or surgical correction.
5. Metatarsal-Cuniform Exostosis, Ganglion
Further up on top of the foot a bony prominence can form. This occurs near the middle of the foot and is due to the formation of bone spurs in the area. Jamming of two bones can over time, cause the spurring. The condition is named after the bones involved and is termed metatarsal –cuniform exostosis. On occasion, as the spurring forms, a weakening of the joint capsule occurs and a ganglion will form. A ganglion is a soft, rubbery mass, which slowly enlarges. Often the ganglion will form without a spur forming first. Treatment consists of padding the area to reduce the pressure from shoes or surgical removal of the bone spur and ganglion if present (See surgical correction of Metatarsal-cuniform exostosis).
Yet another area that can demonstrate a lump or bump on the top of the foot is an area just below the ankle on the outside of the foot. Normally there is a small fleshy area. This is the only muscle on the top of the foot called the Extensor digatorum brevis muscle. Some people have a larger muscle than others and the area may appear enlarged. The area may also enlarge if a lipoma or ganglion forms in this area. A MRI is a useful test to determine if a lipoma or ganglion is present. No treatment is recommended if there is no pain associated with the area.
Painful Bumps on the Back of the Heel
The common cause of a painful bump on the back of the heel is called Hagland’s deformity. This is due to an enlarged bony prominence on the back of the heel. It can involve the entire back of the heel or just a portion of the back of the heel, usually on the outside portion of the heel. Also called the Pump Bump, it is most common in women and is frequently a result of pressure from the back of the shoe. As the shoe rubs on the back of the heel bone it begins to swell and enlarge. Quite often a bursa will form. A bursa is sack that is created over any bony promance when excessive pressure or friction to the areas occurs. Bursa can be filled with a thick watery like fluid.
Treatment of Hagland’s Deformity and Pump Bumps
Treatment consists of removing the pressure and avoiding shoes, which rub on the back of the heel. Orthotics, custom molded shoe inserts, can be useful because they reduce the rocking motion side-to-side of the heel while walking which aggravates the painful area. Cortisone injections can temporarily reduce the pain or eliminate the pain. Surgery can be the treatment of choice if other means to reduce the pressure are unsuccessful.
Spurring in the Achilles tendon
Closely related to Hagland’s deformity is an enlargement that can occur on the back of the heel that is a result of the formation of a large spur where the Achilles tendon attaches. Treatment is the same as with the Hagland’s deformity except that the surgical procedure to remove the spurring is more complex and has a longer recovery period.
Swelling and lumps can also occur in the Achilles tendon just above its attachment into the heel bone. Termed Achilles tendonitis, this occurs when there is a tear in the tendon. If this goes untreated the tendon is at risk of rupturing. Treatment consists of immobilization with a cast, possibly crutches to take weight off the foot, oral anti-inflammatory drugs and if severe of surgery. Once the area is healed aggressive physical therapy and calf muscle stretching exercises. There is another small tendon that attaches in the back of the heel that can become injured. It is called the Plantaris tendon. This tendon can tear or rupture during exercise. It is associated with a sudden onset of pain during exercise and mimics Achilles tendonitis.
An Uncommon Cause – Xanthomas
An uncommon cause of small lumps in the Achilles tendon, called Xanthomas, are due to an excessively high cholesterol level in the blood stream. This is a hereditary disorder that results in the deposition of cholesterol in the Achilles tendon. This is a serious condition and requires aggressive treatment by a physician to lower the cholesterol levels. Left untreated the high cholesterol levels can lead to premature heart attach and death.