Plantar Fibromatosis

Plantar Fibromatosis is a common soft tissue mass found in the foot
and one of the most common lesions found on the sole of the foot. It
is a locally aggressive idiopathic proliferative fasciitis of the
plantar aponeurosis or subcutaneous thickening of the plantar
fascia. It is usually bilateral and frequently seen in children and
young adults. In older people it is often associated with
Dupuytren's contracture of the palmar fascia of the hand. The basic
microscopic pathology of Dupuytren's contracture and plantar
fibromas is about the same. The causes are obscure, but trauma does
not play an important role. The disease usually occurs in adult
males after 40 years. A relatively small number of cases are
bilateral. Whether these tumors are familial is not clear, although
cases have been recorded in multiple members of a family. Compared
with palmar fibromatosis, the plantar variety is rare, although the
exact incidence is not known, since a large number of theses cases
are not reported. The lesion was described by Dupuytren, and later
it was described in more detail by Ledderhose.

In Allen and Woolner's series of 69 cases, 35% were 30 years of age
or younger, including two cases that were present at birth. Among
200 consecutive cases, which were reviewed at the Armed Forces
Institute of Pathology between 1960 and 1978, 111 (55%) occurred in
patients 30 years or younger. Of the 11 cases, 22 were children 10
years or younger. Aviles et al., reported that 77% of their cases
were encountered in patients older than 45 years. Zamora et al.,
Journal of Hand Surgery, 1994 showed that there is an increase in
transforming growth factor beta in the early phase of Dupuytren's
contracture and Plantar Fibromatosis.

As far as clinical findings are concerned, the lesion (plantar
fibroma) appears as a firm, single, subcutaneous thickening or
nodule that adheres to the skin and is located in the middle and
medial portion of the sole of the foot. It may be asymptomatic, but
it may cause mild pain after long standing or walking.

Locke has classified plantar fibromatosis as proliferative(increased
fibroblasts and cellular activity), active(nodules are formed), and
residual(decreased fibroblastic activity).

One should consider surgery if there is pain and a change in the
course of the lesion (increase in size, contracture).

Surgical incisions may be linear, S-shaped or zig-zag. The surgeon
needs to perform a wide excision of the mass. The patient should try
to remain non-weight bearing for 3 weeks if possible.

Some complications are recurrence, nerve entrapment, skin slough,
scarring, hematoma, and arch fatigue. Simple excision appears to be
a poor method of treatment. Allen et al. noted recurrences in 15 of
28 patients treated by simple excision. Patients who underwent local
excision had a 57% incidence of recurrence at the excision site,
whereas those who underwent side excision (fasciectomy) with or
without skin graft had a more favorable result (8% recurrence).