Dermatofibroma

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Classification according to ICD-10
D23.9 Other benign neoplasms: skin, unspecified
ICD-10 online (WHO version 2019)

A dermatofibroma ( syn .: Cutaneous fibrous histiocytoma , fibroma simplex , fibroma durum , hard fibroma ) is a common benign tumor of the skin ( dermis ). The small, up to one centimeter in diameter skin overgrowth occurs preferentially on the arms and legs as well as on the trunk. It consists of collections of connective tissue cells ( fibrohistiocytes ) with interposed collagen fiber bundles (see collagen ).

Predilection sites

Dermatofibromas can appear on any part of the skin of the body, but prefer the extremities , affecting the legs more often than the arms. Dermatofibromas of the palms of the hands and soles of the feet are described in the scientific literature, but are considered a rarity.

Age and gender distribution

Dermatofibromas can occur at any stage of life, but are more commonly found in young adults. Women are affected slightly more often than men.

Appearance

Dermatofibromas are usually small, round, non-painful lumps of a coarse consistency . The size of these tumors is usually less than one centimeter. Very “cell-rich” dermatofibromas and in particular the angiomatoid variant of the dermatofibroma can reach sizes of several centimeters. Dermatofibromas are usually reddish gray or light brown, rarely dark brown, but can also be bluish red or yellowish depending on the content of blood vessels , lipids , hemosiderin and other pigments .

histology

Histologically , dermatofibromas consist of proliferates of fibrohistiocytic cells with interposed collagen fiber bundles that are intertwined like a concertina. The tumor is usually exclusively in the dermis , but can also grow into the subcutis below. Dermatofibromas do not have a capsule and are fuzzy from the neighboring dermal connective tissue . A typical feature of dermatofibromas is that the collagen fiber bundles at the edge of the lesion gradually “lose” in normal dermal connective tissue. The tumor is separated from the covering squamous epithelium of the skin by a narrow so-called "border zone". In almost two thirds of the cases, the covering squamous epithelium of the skin is acanthotically enlarged and shows lentiginous melanin pigmentation . The morphological picture of dermatofibromas varies according to the content of collagen fibers , fibrohistiocytic cells, pigment , lipids and blood vessels .

Differential diagnosis

The histological diagnosis of a conventional dermatofibroma is usually easy for the skilled person. The differentiation from the very rare Dermatofibrosarcoma protuberans causes difficulties .

therapy

From a medical point of view, there is no immediate indication for treatment. At the request of the patient, e.g. for cosmetic reasons, the treatment of dermatofibroma consists of simple surgical removal . After local removal, five percent of dermatofibromas recur .

swell

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