The fibromatoses represents a wide spectrum of locally infiltrative clinicopathologic processes characterized by the proliferation of generally mature fibroblasts associated with mature collagen. Some of these entities are present at birth or develop in early childhood (eg, juvenile fibromatosis [JF]). Others may appear in adulthood.
The term plantar fibromatosis (PF) is used for different conditions, as follows: (1) a relatively common plantar equivalent of Dupuytren palmar contracture named Lederhose disease (LD); (2) a more uncommon plantar superficial fibromatosis that, unlike deep fibromatosis (eg, abdominal, extra-abdominal, and visceral fibromatosis) generally has a less aggressive and recurrent tendency; and (3) an extremely rare, benign cerebriform mesodermal hamartomatous proliferation that, in a plantar location, appears to be a clinicopathologic marker of Proteus syndrome (PS).
Juvenile aponeurotic fibroma (JAF) and aggressive infantile fibromatosis (AIF) can also be considered to be in the plantar fibromatosis group when lesions are present on the sole of the foot.
Plantar fibromatosis represents not a single entity, but rather, a heterogeneous group of conditions with the common characteristics of plantar location and histologic features of mature collagen and fibroblasts with no malignant cytologic features.
In Lederhose disease (described in 1897), as in Dupuytren contracture (DC) (first reported in 1831), repeated trauma, long-term alcohol consumption, chronic liver disease, diabetes, and epilepsy have been reported in association with the development of the lesions in middle-aged or elderly people. Often, patients with Lederhose disease also have other fibrosing conditions such as Dupuytren contracture, knuckle pads, or induratio penis plastica (ie, Peyronie disease, first reported in 1743 by François de la Peyronie, physician of Louis XV of France). Heredity is also a clear factor in many patients.
Superficial fibromatosis (SF) in a plantar location includes a variety of soft-tissue tumoral proliferations of fibroblasts. However, it has been shown that some forms are not due to fibroblast overgrowth but to myofibroblast proliferation; superficial fibromatosis is more common in children and young adults than in older people.
Cerebriform mesodermic hamartomas on the soles represent a kind of mesodermal nevus and are usually associated with Proteus syndrome. This syndrome was named after the Greek god Proteus, the "Old Man of the Sea" and son of Poseidon who was able to change his shape to protect himself. Proteus syndrome is a complex malformative or asymmetric hypertrophic syndrome associated with multiple cutaneous and musculoskeletal manifestations such as epidermal verrucous nevus, vascular hamartomas, and exophytic cerebriform fibrolipomata and scoliosis, kyphosis, and exostosis, respectively. Hamartomatous cerebriform plantar fibromatosis may develop on the soles before other manifestations of Proteus syndrome appear, and it is considered a marker for Proteus syndrome.
Fibromas and desmoid tumors (eg, intestinal polyps, osteomas, soft-tissue tumors, epidermal cysts) are common in Gardner syndrome, which was described in 1950. These tumors often arise over previous surgical scars. By means of direct DNA sequencing, recent studies show that somatic beta-catenin or adenomatous polyposis coli (APC) gene mutations are present in virtually 100% of cases of Gardner syndrome–associated fibromatosis (GAF), as well as most cases of deep fibromatosis (DF). On the other hand, no somatic mutations were identified in beta-catenin or APC genes in superficial fibromatosis. Therefore, the divergent behaviors of superficial fibromatosis in relation to deep fibromatosis and Gardner syndrome–associated fibromatosis, despite their similar clinical and histologic morphologic features, are based on genetic differences.
Lederhose disease is relatively common, and plantar contracture develops in approximately 25% of middle-aged or elderly individuals (1 of every 4 with Dupuytren contracture). Superficial plantar fibromatosis (SPF) is uncommon, and the hamartomatous form associated with Proteus syndrome is rare. The exact incidences of superficial plantar fibromatosis and the hamartomatous form associated with Proteus syndrome are unknown.
Whites are affected more often than other groups.
Lederhose disease affects men approximately 10 times more often than it affects women. Juvenile aponeurotic fibroma is more common in boys than in girls. No sex predilection is evident for the other forms of plantar fibromatosis.
Lederhose disease is seen in middle-aged and elderly people. Superficial plantar fibromatosis and juvenile aponeurotic fibroma are most common in children and youths than in adults. The exceptional aggressive infantile fibromatosis begins in an infant's first year of life. The rare hamartomatous variety also develops in infants.
The different varieties of plantar fibromatosis may be asymptomatic. However, the feeling of a mass in the foot, difficulty fitting in shoes, and pain with weight bearing often affect patients' ability to stand or walk.
Only aggressive infantile fibromatosis has an invasive course, as does fibrosarcoma; however, it does not metastasize.
Lederhose disease has a favorable prognosis, although slow progression is not uncommon. Patients who undergo plantar fasciectomy have been shown to have a lower recurrence rate.
Superficial plantar fibromatosis is usually benign and may regress spontaneously. Rare cases that are relatively progressive and recurrent occur. The hamartomatous form is also benign, and problems are related to difficulties in standing or walking or to associated Proteus syndrome.
Juvenile aponeurotic fibroma is benign, but recurrences are common.
Patients with Lederhose disease are not often aware of their disease because it is usually not painful.
Likewise, patients with other forms of plantar fibromatosis may not be aware of their disease; however, they may notice difficulty in standing, walking, or wearing shoes when nodules or bumps become big enough.
Lederhose disease is typically bilateral and progresses slowly but not indefinitely.
Superficial plantar fibromatosis may grow gradually, and, in most cases, self-involution occurs. In some cases, superficial plantar fibromatosis lesions enlarge and persist; if excised, they recur iteratively.
Juvenile aponeurotic fibroma can spontaneously regress or persist. Recurrences after excision are common.
Lederhose disease consists of one or more small, asymptomatic, round or flattened, hard nodules that are generally located on the medial side of the sole. Flexion deformities usually do not occur in opposition to Dupuytren contracture.
Superficial plantar fibromatosis appears as one or more asymptomatic, bad limited, flat nodules of fibrous consistency and variable size. They are most commonly located on the plantar aspect of the anteromedial portion of the heel pad (see the image below).
Superficial fibromatosis of the heel.
Juvenile aponeurotic fibroma may appear as a localized form affecting adults or a diffuse variety observed in children. It is more common in males than in females, and the hard nodules grow slowly and adhere to deep structures (see the image below).
Juvenile aponeurotic fibroma.
Aggressive infantile fibromatosis is rare and ordinarily begins in the patient's first year of life. It grows rapidly and infiltrates the subcutaneous tissue, aponeurosis, and muscles with an expansive or infiltrative course like a fibrosarcoma. However, metastasis does not occur.
Hamartomatous plantar fibromatosis lesions look like raised cerebriform soft-to-firm exophytic masses on any plantar area, where they are covered by pink, lightly dark, or normal-colored skin (see the image below). They can become large enough to cause disability.
In patients with Lederhose disease, the presence of other fibrosing conditions (eg, Dupuytren contracture, knuckle pads, Peyronie disease in men) must be checked.
In superficial plantar fibromatosis, Gardner syndrome must be ruled out.
In the presence of cerebriform fibrous exophytic plantar lesions, Proteus syndrome must be considered.
As with many tumors, the causes are not known.
MRI is useful in detecting plantar fibromatosis. Images show some signal intensity heterogeneity and, usually, infiltrative margins. MRI can show the degree of deep invasion of the plantar fibromatosis, which often reaches the aponeurosis.
The MRI signal intensity and the consistency of the clinical location of Lederhose disease enable the diagnosis to be made with reasonable confidence. However, one must consider the diagnosis of clear cell sarcoma in the differential. In effect, the 2 entities can have similar MRI findings and clinical locations.
For fluorine-18 fluorodeoxyglucose (FDG) imaging, see Scheler et al.
All types of plantar fibromatosis have a dense fibrocellular tissue with mature collagen and fibrocytes in various stages of maturation, but they do not have prominent atypical features or abnormal mitotic activity. The overlying epidermis and superficial dermal tissue are usually normal, but the neoformation, which grows upward and downward, generally replaces the adipose tissue. The proliferation often involves many cellular foci surrounded by fibrous scarlike connective tracts.
In superficial plantar fibromatosis, the limits are usually undefined. Some areas may be almost acellular, with a scarlike appearance. In other areas, or in the most active early cases, the fibrocytic component can be dense, with cells closely packed together; the differential diagnosis with fibrosarcoma can be difficult in these cases. The reticulin network is often prominent. Usually, inflammation-associated infiltrate is not present. The connective stroma may involve various aspects. The stroma may be dense and fibrous; less commonly, it is loose. Sometimes, myxoid or chondroid areas can be seen. Vascularization is not a prominent feature. Local nerves and Vater-Pacini corpuscles can seem to be increased in number or size.
In juvenile aponeurotic fibroma, the cells are round or oat-shaped, and the stroma is chondroid (cartilage analogue fibromatosis). Aggressive forms are usually more cellular and have increased mitotic activity. Peripherally, the proliferation is poorly limited and penetrates the neighboring structures. Hamartomatous cerebriform plantar fibromatosis has a variable fibromalike, lipomatous, angiolipomatous, or combined structure.
The myofibroblast is the key proliferative cell in some so-called fibromatoses; therefore, these might be better named myofibromatoses. In these fibromatoses, results of tests for cytologic markers in muscle cells are positive.
In recurrent plantar fibromatosis, as in aggressive fibromatosis, tumoral cells express platelet-derived growth factor-B (PDGF-B) proto-oncogene. This proto-oncogene encodes the B chain of PDGF-B, a mitogen for fibrocytes, whereas normal plantar fascia, nonrecurrent plantar fibromatosis, and scars do not. Thus, the detection of PDGF-B may be a useful adjunct to the pathologic evaluation of invasive plantar fibromatosis for prognostic purposes.
Osseous metaplasia and distinct multinucleate giant cells have been reported in Lederhose disease.[8, 9]
No medical care is effective in plantar fibromatosis, and reported success probably is due to the possible spontaneous involution of superficial plantar fibromatosis. Early treatments have included anti-inflammatory medication, orthotics, and physical therapy. Other modalities have included methotrexate and radiation after surgery.
For Lederhose disease, the intralesional injection of corticosteroids has been tried, but its usefulness is doubtful, and these injections may have some utility at only the initial stage.
For Lederhose disease, fasciectomy and excision of the fibrous tissue are the only possible treatments, if needed. Fasciectomy has been shown to reduce the rate of recurrences.
For the other forms of plantar fibromatosis, surgery is the only therapeutic alternative. However, in infantile forms, physicians should evaluate the need for surgery before performing it.
Many juvenile fibromatoses spontaneously regress, and biopsy may be performed to induce their involution. Some lesions can grow, and others can recur after excision that appears complete. Because tumor growth characteristics may be relatively important before surgery, physicians should consider the possibility of an expectant control.
Hamartomatous plantar fibromatosis does not regress spontaneously; therefore, surgical removal is appropriate.
Modification of activity, the use of orthotics, and physical therapy have been used as therapeutic modalities for the treatment of plantar fibromatosis.