Infantile digital fibromatosis
Infantile digital fibromatosis | |
---|---|
Other names | Inclusion body fibromatosis, Infantile digital myofibroblastoma, Reye tumor, Reye's tumor |
Specialty | Pediatrics, Dermatology |
Usual onset | Typically at birth or infancy |
Causes | Unknown |
Prognosis | Excellent |
Frequency | Rare |
Infantile digital fibromatosis (IDF), also termed inclusion body fibromatosis, Reye tumor, or Reye's tumor, usually occurs as a single, small,
IDF consists of an overgrowth of spindle-shaped cells in a collagen fiber-rich background located in the dermis (i.e. the layer of skin between the epidermis and subcutaneous tissue) but may extend into the subcutaneous tissue. These spindle-shaped cells contain distinctive inclusion bodies within their cytoplasm that greatly help in distinguishing IDF from other fibrous skin diseases. These inclusions are composed of densely packed vimentin and actin filaments.[6]
IDF lesions are usually painless and have a tendency to regress spontaneously. Consequently, the current recommended treatment for IDF nodules is conservative observation.[3] If the lesions cause local deformities and/or functional impairments or continue to increase in size over long observation periods, surgical removal is recommended. However, surgically removed IDF lesions have had high rates of recurrence and this surgery may cause post-operative digital deformities.[6]
Presentation
IDF typically presents as a solitary painless, smooth, flesh-colored to red, dome-shaped nodule located on the dorsal or lateral aspect of a finger or toe but sparing the thumb or great toe;[3] they occur principally in the first two years of life with about one-third of cases having a lesion since birth.[6] However: 1) lesions with appearances similar to, and diagnosed as, IPF have been described in extra digital sites such as the arm, breast, tongue, thigh,[3] and chest;[6] 2) unusual cases have presented with multiple lesions, i.e. 2–3, uncommonly 7–15, and one case with 74 lesions in a 2018 review study;[7] 3) cases have been reported in children up to the age 10 and one case was reported in a 52-year-old adult;[8] 4) the lesions are typically smaller than 2 cm in maximum diameter[3] but rarely have been tumor-sized, e.g. 4.5 cm;[6] 5) the lesions, particularly when larger-sized, may be painful and/or compromise the functions of nearby joints and digits;[7] and 6) the lesions occasionally invade the periosteum and erode a nearby bone.[6]
Pathology
Microscopic
Diagnosis
The diagnosis of IDF is usually based on its presentation in newborn or young infants and
Infantile myofibromatosis (IMF) is, like IDF, a disease in which benign tumors develop primarily in the fingers and toes of newborns and infants and consists of spindle-shaped cells in a collagen fibrous background. IDF was once regarded as a sub-type of infantile myofibromatosis. However, IMF tumors can be far more aggressive than IDF lesions and consist of cells that do not have paranuclear inclusions.[2] The World Health Organization (2020) classification includes IPF but not IMF as a tumor in the category of benign fibroblastic and myofibroblastic tumors.[4]
Treatment
Infantile digital fibroma lesions were once thought to be potentially malignant and therefore treated with surgical excision and even digital amputations.
See also
- Infantile fibromatosis
- Skin lesion