Fibromatosis

The term fibromatosis was proposed by Stout for a group of related conditions having in common the following features:

1. Proliferation of fibroblasts/myofibroblasts
2. Infiltration pattern of growth
3. Presence of variable (often abundant) amount of collagen, between proliferating cells
4. Lack of cytological features of malignancy
5. Absence of mitotic activity
6. Aggressive clinical behaviour (recurrences)

There are three variants of fibromatosis, apparently restricted to childhoods that present distinct clinicopathological picture: fibromatosis colli, infantile digital fibromatosis and infantile myofibromatosis (for details see Soft tissue Chapter)