Infantile Digital Fibromatosis 

Updated: Apr 11, 2019
Author: Monique Gupta Kumar, MD, MPhil; Chief Editor: Dirk M Elston, MD 

Overview

Background

Infantile digital fibromatosis is a benign asymptomatic nodular proliferation of fibrous tissue occurring almost exclusively on the dorsal and lateral aspects of the fingers or the toes, as is shown in the image below.[1] Reye first described infantile digital fibromatosis in 1965 as a recurring digital fibrous tumor.[2]

Firm, nontender, erythematous nodule on the fifth Firm, nontender, erythematous nodule on the fifth finger of a 17-month-old boy.

Pathophysiology

The etiology of infantile digital fibromatosis is unknown. Defective organization of actin filaments in myofibroblasts has been hypothesized. It has been suggested that possible deregulation of the normal bone morphogenetic protein (a member of the transforming growth factor-β superfamily) mediated apoptotic pathway may explain the location of these lesions at the sites of digital septation. Transforming growth factor-β1 also mediates myofibroblast differentiation from fibroblasts.[3, 4]

Epidemiology

Frequency

Infantile digital fibromatosis is rare, with approximately 250 cases reported worldwide.

Sex

Males and females are equally affected by infantile digital fibromatosis.

Age

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. Reports of infantile digital fibromatosis developing in older children and adults are rare.

Prognosis

The prognosis for infantile digital fibromatosis is excellent. Infantile digital fibromatosis is benign, without evidence of malignant transformation or metastases. There may be single or multiple nodules. Infantile digital fibromatosis lesions tend to spontaneously involute without scarring. Rarely, the lesions can cause functional impairment or deformity. Rare cases of ulceration have been reported. The infantile digital fibromatosis lesions tend to grow slowly in the first month, then rapidly grow over about a year, followed by spontaneous resolution over 1-10 years (average 2-3 y). Recurrence is common after excision.

 

Presentation

History

Patients with infantile digital fibromatosis are asymptomatic, without associated systemic symptoms.

Physical Examination

Single or multiple, firm, pink, dermal nodules with a smooth dome-shaped surface appear on the dorsolateral aspect of the distal phalanges of the digits. Infantile digital fibromatosis lesions can grow up to several centimeters in diameter. There is often deformity of the affected digit; however, they rarely cause functional impairment. Lesions are more common on the fingers than on the toes and spare the thumbs and great toes. Rarely, more than one digit is involved. Rare extradigital sites reported include the hands, feet, arms, nose, breasts, torso, and tongue.[5]

Complications

The infantile digital fibromatosis lesions rarely cause functional impairment or deformity, but they have become ulcerated in some instances.

 

DDx

 

Workup

Procedures

A skin biopsy can confirm the diagnosis of infantile digital fibromatosis.

Histologic Findings

Unique histologic features are diagnostic of infantile digital fibromatosis. Interlacing fascicles of uniform spindle-shaped myofibroblast cells and collagen bundles are seen in the dermis or subcutis. A characteristic feature is the presence of distinctive, perinuclear, eosinophilic cytoplasmic inclusion bodies. Masson trichrome stains these characteristic perinuclear inclusion bodies red. Immunohistochemical stains are positive for vimentin, cytokeratin, desmin, calponin, and alpha-smooth muscle actin.[6]

See the images below.

Dermal tumor with interlacing spindle-shaped cells Dermal tumor with interlacing spindle-shaped cells and collagen bundles. Perinuclear eosinophilic inclusion bodies are not visible at this magnification.
A dermal nodule extending into the subcutaneous fa A dermal nodule extending into the subcutaneous fat.
 

Treatment

Medical Care

Because of the benign nature of infantile digital fibromatosis, frequent recurrence after surgery, and tendency toward spontaneous resolution,[7, 8, 9] observation is suggested.[10]

Surgical Care

Of infantile digital fibromatosis lesions, 60-90% are reported to recur with local excision, and surgery is recommended only if there is functional impairment.[11] Mohs micrographic surgery using smooth muscle actin or trichrome stains has been successful in a few cases that required surgery.[12]  Cryotherapy has also been used successfully.[13]

 

Medication

Medication Summary

Topical corticosteroids with or without occlusion have not shown any benefit in infantile digital fibromatosis; however, intralesional corticosteroids or fluorouracil may prove beneficial.[14, 15]

Corticosteroids

Class Summary

Anti-inflammatory agents may induce regression of dermal infiltrative lesions.

Triamcinolone (Aristocort)

Triamcinolone is used for inflammatory dermatosis responsive to steroids. It decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing capillary permeability. Triamcinolone can be injected intralesionally.

Antimetabolites

Class Summary

These agents inhibit cell growth and proliferation.

Fluorouracil (Efudex, Adrucil, Fluoroplex)

Fluorouracil is a pyrimidine analogue that has been shown to inhibit dermal fibroblast proliferation and collagen synthesis in cell culture.