The most common disorder that occurs on the bottom of the foot and presents like a soft lump in the arch region is known as a Plantar Fibroma. This is a disorder where a soft tissue mass forms or develops within the plantar fascia which is located on the bottom of the foot. The plantar fascia is located in the arch region and helps to support the arch while we are standing.
What is Plantar Fibroma?
A Plantar Fibroma is most often a benign soft tissue mass. The most common complaint is pain upon standing on the foot. The mass can get irritated and inflamed from the pressure of the body weight when we are standing.
An MRI or a soft tissue scan can be very useful in locating the fibroma and determining the size. X-rays can be taken to see if there is any bone involvement but they usually are negative.
Surgery is recommended for the fibromas only if pain is persistent. Following surgery, a biopsy of the lesion is performed, in order to confirm the diagnosis of a plantar fibroma.