Fibrous tumours

There are several types of fibrous tumours that can affect the nails, fingers, toes and much less commonly others sites.

This chapter is set out as below:

Acquired (digital) fibrokeratoma

• Lesions manifest as solitary, skin-coloured, dome-shaped papules or tall fingerlike protrusions with a hyperkeratotic surface. Most are less than 1.5 cm in height or diameter
• A distinguishing feature is that of a collarette of slightly raised skin that encircles the base of the lesion 

Periungual fibromas of tuberous sclerosis

• Similar growths to the above are found in the subungual or periungual region of patients with tuberous sclerosis, and are referred to as Koenen tumours or garlic clove fibromas
• Lesions develop around puberty and in young adults
• They tend to be multilobulated, involve several digits and, histologically, may have atypical stellate myofibroblasts
• Nail involvement is common
• Refer to the related chapter on tuberous sclerosis for more information 

Acquired fibrous nodule

• Is a true fibroma
• It usually presents as a smooth-edged lesion, commonly in the periungual tissue as opposed to within the nail unit
• Lesions are generally devoid of a hyperkeratotic surface 

Infantile digital fibromatosis

• This is a rare condition, manifested by the benign, asymptomatic, nodular proliferation of fibrous tissue occurring almost exclusively on the dorsal and lateral aspects of the fingers or toes
• Most nodules appear in the first few months of life; one third are congenital, and 75-80% are noted during the first year of life
• Clinical features
  • Single or multiple, firm, erythematous, dermal nodules with a smooth dome-shaped surface on the dorsolateral aspect of the distal phalanges of the digits
  • There is sparing of the thumbs and the great toes
  • Lesions can grow up to 2 cm in diameter, yet they rarely cause functional impairment or deformity
• Because of the benign nature of infantile digital fibromatosis, frequent recurrence after surgery, and a tendency towards spontaneous resolution over two to three years, observation is suggested as the best form of management

• Asymptomatic lesions are best left alone

• Symptomatic lesions can be removed by shave excision or curettage and sent for histology

• Infantile digital fibromatosis - refer to the section above on clinical findings