Plantar Fibromatosis

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. ^[1]

The term plantar fibromatosis (PF) is used for different conditions, as follows: (1) a relatively common plantar equivalent of Dupuytren palmar contracture most commonly termed Ledderhose disease (LD), but also referred to as morbus Ledderhose; (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 Ledderhose 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. The development of clinically apparent disease actually occurs later in the condition’s development as the initial stages are clinically imperceptible and involve a reduction in existing collagen networks with a corresponding increase in fibroblast activity. Clinical manifestations appear during the “active” or “involution” stage as fibroblast maturation leads to increased collagen synthesis and the beginnings of the characteristic nodule formation, usually in the medial plantar aponeurosis. This active phase also derives its namesake from the active contraction of the plantar aponeurosis by differentiated myofibroblasts within the tissue. ^[2] Patients with Ledderhose disease often 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). In fact, literature has shown that concurrence of Ledderhose disease and Peyronie disease to Dupuytren contracture ranges from 9% to 25% and 4%, respectively. ^[2] This indicates that heredity is a likely factor for the development in patients, and work by Hu et al has suggested the relatively high concurrence frequency is suggestive of a commonly shared defect in wound repair, as Ledderhose disease can develop secondary to repetitive trauma. ^[3]

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 born from of an activating mutation within the oncogene AKT1. ^[4] The syndrome is associated with multiple cutaneous and musculoskeletal manifestations such as epidermal verrucous nevus, vascular hamartomas, and exophytic cerebriform fibrolipomata and scoliosis, kyphosis, and exostosis, respectively. ^[5] 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. ^[6]

As with many tumors, the causes are not known. As previously stated, owing to the high concurrence rate with Dupuytren contracture, there is suspicion that a shared defect in wound repair could be to blame, but no definitive etiology has been elucidated to date. ^[3]

Frequency

Ledderhose 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.

Race

Whites are affected more often than other groups. ^[2]

Sex

Ledderhose 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.

Age

Ledderhose disease is seen in middle-aged and elderly individuals. Superficial plantar fibromatosis and juvenile aponeurotic fibroma are most common in children and youths when compared with 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.

Ledderhose 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.