There are a number of different soft
tissue and bone tumors that are found in the foot. This discussion will be
broken into two sections, benign and malignant tumors.
Benign Soft Tissue Tumors of the
Foot
Eccrine poroma - This tumor is
typically found on the glabrous surface of the palms and soles. Eccrine
refers to the gland that allows us to perspire.
Etiology - there is no consensus
regarding the origin of this tumor but it is thought to represent an occluded
sweat gland. Eccrine poromas may be flat or raised, with partial or full
discoloration being red or brown.
Symptoms - symptoms occur with pressure or weight bearing such as the plantar
surface of the foot.
Treatment - preferred treatment is curettage or excision under local
anesthesia. Recurrence is rare.
Ganglionic cysts - the origin of ganglionic cysts is
debated, but these cysts are fluid filled cysts. The most common
location for ganglionic cysts in the foot is the lateral side of the
arch. (click on link for additional information)
Glomus tumor - a tumor of vascular origin found in the
extremities. Often found beneath the nail.
Etiology - tumors of vascular origin that have an undetermined
etiology.
Symptoms - pain with weight bearing or pressure from shoes.
Treatment - preferred treatment is excision under local
anesthesia. Recurrence is rare.
The following images show the steps used to excise a glomus tumor.
Image 1 show pre-operative planning. the glomus tumor is surrounded by 3
blue dots. The remaining images show excision of the tumor and closure of
the wound.
Intractable plantar keratoma - this
benign soft tissue tumor is actually a unique form of callus. This
callus forms a core beneath a weight bearing surface such as the plantar
surface of a metatarsal head. (click on link for additional information)
Etiology - load bearing on the skin.
Symptoms - pain with weight bearing.
Treatment - periodic debridement or metatarsal osteotomy. A
metatarsal osteotomy is a procedure where the load bearing bone
(metatarsal) is intentionally broken in a surgical procedure that mimics
a stress fracture.
Mucoid cyst - Also known as a myxoid cyst, periungual
ganglion, mucinous cyst. Many authors believe that the gelatinous contents
of this cyst
arise from the synovial lining of an adjacent tendon or joint. These
cysts are common and are often found adjacent to the nails on the fingers and
toes.
Etiology - unknown - believed to be due to a herniation of an
adjacent tendon or joint space.
Symptoms - pain with weight bearing.
Treatment - periodic aspiration or wide excision.
Plantar fibromatosis - plantar
fibromatosis (PF) is a fairly aggressive benign tumor of the plantar
fascia. The plantar fascia is a broad band that runs from the plantar
aspect of the calcaneus (heel bone) to the plantar aspect of the metatarsal
phalangeal joints (toe joints).
(click on link for additional information)
Synovial cysts - fluid filled tumors that arise from structures that contain
synovial lining such as the interior surface of a joint or tendon. (click on
link for additional information)
Malignant Tumors of the Foot
Malignant melanoma - this aggressive tumor may be
found virtually anywhere on the body and is one of the few primary
malignancies
found on the feet and legs. The rate of malignant melanoma has doubled over the
past 30 years with an estimated 53,000 new cases being diagnosed in the United
States alone each year. Although malignant melanoma accounts for only 1%
of all reported skin cancers, it accounts for over 60% of all skin cancer
deaths. It metastasized early and its' metastases are difficult to treat.
For many forms of this tumor, the 5
year survival rate is very poor with typical metastasis to the bone or
liver. Several different forms of malignant melanoma are known.
Etiology - dysplasia of the melanocytes
Symptoms - pain with irritation or weight bearing
Treatment - aggressive and often a combination of surgical, radiation therapy
and/or chemotherapy
Kaposi's Sarcoma - vascular tumor that may appear in three
distinct forms; (1) indolent, (2) lymphadenopathy and (3) Acquired immune
deficiency syndrome.
Etiology
- Mixed vascular structures
Symptoms - Indolent - painful lesions of the foot and leg. The
lymphadenopathy form shows wide dissemination in the lymph system.
Treatment - combination of surgical excision, radiation and chemotherapy.
Squamous cell carcinoma - this is a slow growing
form of epidermal cancer that is typically limited to area of excessive sun
exposure. Squamous cell Cancer is the second most common form of skin
cancer second only to basal cell carcinoma.
Etiology
- dysplasia of the epidermis, commonly associated with sun exposure.
Symptoms - the formation of plaque called actinic or senile keratoses.
Treatment - excision.
