Infantile digital fibroma (or fibromatosis) presents as single or multiple gelatinous or firm pinkish nodules on the fingers or toes of an infant. Similar lesions are occasionally diagnosed elsewhere on the hands, feet, arms or elsewhere on the body. In one-third of cases, they are present at birth. They are rare and are seen in both males and females.
Although infantile digital fibromas may grow to a size of 2cm, they are harmless and do not usually cause any symptoms unless they rub on the neighbouring toe or footwear. The cause of infantile digital fibromatosis is unknown.
An infantile digital fibroma is sometimes confused with a bony lump called an exostosis. It may be necessary to have the toe X-rayed to see the extent of the nodule.
A skin biopsy can confirm the diagnosis. The histology of infantile digital fibroma is characteristic, showing interlaced spindle-shaped cells and collagen fibres within the dermis (mid layer of skin) and subcutaneous tissue (under the skin). The cells include unusual inclusion bodies and are thought to be myofibroblasts (the cell type that makes muscle fibres).
Eventually, many fibromas resorb and disappear by themselves over 2 to 3 years so that a conservative wait and see approach is best if they are not causing problems. If desired, they can be removed by a simple surgical procedure in which the lump is shaved off. However, many recur after surgery.
