There are several types of masses of tumors the foot can develop for numerous medical reasons. When people hear the words “mass” or “tumor”, it can be concerning since people often associate them with cancer. However, there are numerous foot masses involving the soft tissues that are benign, and not affiliated with cancers or any serious ailments. These masses can, however, cause discomfort when walking, standing, or sitting. The most common benign soft tissue tumor of the foot is a lipoma.
Lipomas are soft tissue tumors that occur in the subcutaneous tissues just beneath the skin. They are growths of fat cells, contained in a fibrous capsule, and are generally small (usually less than 5 centimeters in diameter). These often present as a small, palpable, and rubbery mass on the foot. These lesions grow slowly and are not considered to be harmful. While they are not usually accompanied with pain, lipomas can cause pain if they are compressing nerves or other structures in the foot. The exact cause of lipomas is not known, but are commonly seen in patients who are middle-aged and obese. Lipomas are generally classified as being one of two types: superficial or deep.
- Superficial lipomas are more common and well-circumscribed; this makes it easy to distinguish from similar surrounding structures.
- Deep lipomas are not as well-circumscribed and can be difficult to distinguish from other surrounding soft tissue structures; this can make it harder to excise if treatment is needed.
Since these lipomas are benign and do not transform into cancer, removal is not always necessary unless there is nerve compression, uncertain diagnosis of another lesion (i.e. ganglion cyst or plantar fibroma), or if the patient has cosmetic concerns. If treatment is needed, surgical excision can be done to remove the mass. Since the lipoma has a capsule, a local extracapsular excision is performed to remove the mass, and minimize damage to the surrounding tissues. Alternatively, the lipoma can also be removed by making an incision over the mass, and manually squeezing the lipoma through the incision.
If you have a suspicious mass on your foot and have concerns, please do not hesitate to schedule an appointment with Dr. Jay C. Larson at Sole Foot and Ankle Specialists in Glendale, Arizona, and have all your treatment options presented to you and ensure you and your family maintain healthy feet.