One ailment that can mimic the oh-so-common plantar fasciitis is the presence of various cysts or tumors in the heel bone.
On some rare occasions, pain in your heel can be caused by cysts and tumors within the heel bone (calcaneus). According to the literature, bone tumors of the feet only represent 3-6% of all bone tumors that occur in the body. Of these bone tumors in the foot, only a fraction occur within the heel. While this means that tumors in the heel are quite rare, it doesn't mean that this diagnosis should be excluded from the realm of possible causes of your heel pain. While the number of tumors in the heel are rare, a simple x-ray can provide clues to whether this is a component in your heel pain. It is very important to be aware of the presence of these lesions, as the treatments between these conditions are very different.
Some of the possible bone tumors that occur in the calcaneus (heel bone) are discussed below. Some of these tumors do not cause pain and may be brought to your attention while having an x-ray for an unrelated foot issue. Others can be the cause of pain. There are both benign and malignant bone tumors. The reason that some bone tumors may hurt and others may not is a reflection of their composition and also their growth over time. Some more aggressive tumors grow very rapidly, putting strain on the outer (cortical) bone. While not all rapidly growing bone tumors are cancer, they can become a prominent concern if they put the calcaneus at risk of fracturing.
The most frequently encountered bone tumor in the heel is called an intraosseous lipoma. Intraosseous simply means "within the bone" and lipoma means "fat tumor." These bone lesions are benign and occur more often in males than females. The most typical age group for these to occur in is between 30 and 60 years old. These are most often found when an x-ray is taken for other reasons - meaning that these lesions are not typically painful for people. The treatment for this is, therefore, usually observation. Instances where these tumor require treatment is if they are painful or if their location predisposes the bone to fracturing. In these cases, the tumor needs to be surgically removed and replaced with bone graft. The bone graft allows the bone to heal in a way that makes it stronger and less prone to future fracture.
Another common bone tumore is called an aneurysmal bone cyst. These types of tumors usually occur in the 1st and 2nd decades of life (teenagers). They are made up of clotted and unclotted blood within mesenchymal (a type of connective) tissue. These bone tumors are painful in many cases, due to the fluid within them putting pressure on the surrounding bone. Aneurysmal bone cysts are more common in females than males. Treatment is very similar to the intraosseous lipoma - in instance of pain, it is surgically removed and the void is then filled with bone graft material.
A unicameral bone cyst is a fluid filled tumor. The exact type of fluid present in these tumors is still a topic of debate, but it appears to be similar to serous fluid. Serous fluid is normally present in the joints of the body. For this reason, some hypothesize that these tumors arise from an outgrowth of a growth plate or from the synovial tissue of a nearby joint. These cysts are also benign. They occur in children and adolescents most commonly, and are more prevalent in males than females. These tumors do recur in 25-50% of cases following removal. Treatment in cases where pain is present consists of removal of the tumor and use of bone graft.
The most aggressive of benign tumors that can occur in the calcaneus is the giant cell tumor. The name stems from the composition of this tumor. "Giant cell" is a term used to describe when a collection of cells stick together creating large (or giant) cells. When these tumors present in bone, they appear very worrisome on x-rays, CT scans, and MRI because they can be so expansive. They can often lead to bone deformities and fractures. Giant cell tumors of the bone have a recurrence rate between 10-30%. They occur much more frequently in females than males and usually occur in the 3rd decade of life. Giant cell tumors have been known to lead to "benign metastasis" meaning that they can spread to the lungs, but are not cancerous. Some feel that giant cell tumors are "premalignant" lesions and that they can become cancerous - though this is rare.
One malignant bone tumor that can occur in the calcaneus is chondrosarcoma. The preffix "chondro" means cartilage. These tumors normally present with pain in the heel. X-rays will show an area of bone destruction with a small area of calcification. These tumors can present as primary (original site of cancer) or as secondary (meaning cancer is somewhere else in the body and has spread). While chemotherapy has been used in some cases, In order to completely remove this type of malignant tumor, amputation is commonly necessary. The incidence of this tumor occuring in the foot is less than 3%.
Osteosarcoma is another malignant bone tumor that rarely occurs in the foot (less than 1%). This tumor is seen less often than chondrosarcoma in the foot. It usually presents with pain. These tumors can usually be picked up on a regular x-ray. They require biopsy and usually chemotherapy, with or without amputation.
Ewing's sarcoma is a malignant tumor most often seen in children and young adults. While it is usually found in the leg, it has also been seen in the bones of feet. The Mayo clinic has reported that the incidence of Ewing's is 5%. These tumors present with pain and also are usually accompanied with skin lesions or masses within the foot that can sometimes be seen with the naked eye.
These are only a few of some of the more commonly occuring tumors in the heel bone. While almost all heel pain is NOT caused by a bone tumor in the heel, it is worth being aware that it is a possibility. Don't neglect your heel pain! Whatever the cause, seeing your foot doctor for evaluation is the first step to healing and getting back on your feet.