Dermatofibroma: causes, symptoms, diagnosis, treatment

Dermatofibroma (syn: histiocytoma, angiofibroxantoma, sclerosing hemangioma, fibroxanthoma, nodular and subepidermal fibrosis) is a benign tumor of connective tissue in the form of a slowly growing painless node, a single, rarely multiple nodular or plaque formation with a diameter of about 1 cm, slightly elevated in the center.

The causes and pathogenesis of dermatofibromas have not been studied.

Symptoms of dermatofibroma. In most cases, the disease occurs in women. There is a rounded tumor-like formation deeply embedded in the skin. A tumor is a single or multiple mobile node. The tumor has a small value (from 2-3 mm to 1.0-1.5 cm), a dense consistency and a dark brown color and acts as a hemisphere over the surface of the skin. Also, the tumor can be, as it were soldered, pulled into the skin so that the upper pole ee is at the same level with the skin surface. Subjective sensations are absent.

Palpation dense, it blends easily, the surface is smooth, sometimes hyperkeratomical, verruccus. The color of the bowl is reddish-brown, more saturated in old elements. There is a bowl in young women's tires, mainly on the lower limbs. Multiple disseminated small dermatofibromas can be combined with osteopokiliia (Buschke-Ollendorf syndrome)

Histopathology. Histologically, clusters of mature and young collagen fibers located in various directions are noted. Fibroblasts, histiocytes and an abundance of small blood capillaries with edematous endothelium. Teton multinucleated cells are rare.

Pathomorphology. A large number of synonyms for dermatofibroma indicates a significant variability in the histological pattern. In this regard, some authors identify variants of dermatofibroma in separate nosological units. This applies primarily to options such as angiofibroxanthoma and histiocytoma. In our opinion, it is advisable to consider these tumors as varieties of dermatofibroma, since their morphological features, as well as histogenesis, are similar. They are distinguished only by the predominance of a particular component and the degree of their maturity.

The components of any variant of dermatofibroma are fibroblastic cells, fibrous substances and vessels. Depending on the predominance of the composite component, fibrotic and cellular types of tumor can be distinguished.

Fibrous type is characterized by the predominance of mature and young collagen fibers located in different directions, in places in the form of twisting beams and moiré structures. Areas of young collagen are stained with hematoxylin and eosin in a pale blue color, the fibers are located separately, and not in the form of bundles. Cells are predominantly mature (fibrocytes), but there may be young forms - fibroblasts. The tumor is sometimes sharply delimited from the surrounding dermis, sometimes its boundaries are vague.

The cellular type of dermatofibroma is characterized by the presence of a large number of cellular elements, mostly fibroblasts, surrounded by a small amount of collagen fibers. Among the fibroblasts are located, sometimes in the form of nests, histiocytes. They are larger than fibroblasts, their nuclei are oval, the cytoplasm contains a significant amount of lipids and hemosiderin. In some tumors, histiocytes predominate, among which are (sometimes in large numbers) Tuton cells. These are large cells with numerous nuclei, sometimes coalesced, in a massive cytoplasm. The peripheral parts of the cytoplasm of these cells contain birefringent lipids, sometimes typical xanthoma cells can be seen. In some cases, the latter predominate, located in the form of nests among the fibroblastic elements, in connection with which a similar variant of dermatofibroma is called fibroxanthoma. The stroma of the cell type of fibroma consists of soft, loosely arranged collagen fibers, in places with the presence of rhythmic structures.

In all variants of dermatofibroma, vessels of different caliber with swollen endotheliocytes are found. In some cases, among the cellular elements and fibrous structures there are a large number of capillary vessels, which gives grounds to some authors to call such a tumor a sclerosing hemangioma. Sometimes, along with vessels of the capillary type, larger vessels with sharply widened lumens appear in the form of cracks located in the connective tissue, where collagen fibers form characteristic moiré structures. In fibroblastic elements, birefringent lipids (angiofibrosanthoma according to the classification of LK Apatenko) are found.

Histogenesis. All the above histological varieties of dermatofibroma have a single histogenesis. It is noted. That fibroblastic elements of a tumor have a potency to phagocytosis, therefore they often contain lipids and iron. Scientists have identified the activity of acidic phosphatase in fibroblasts of all types of dermatofibroma. This is confirmed by electron microscopy. Thus, SG Carrington and R.K. Winkelmann (1972). Studying dermatofibroma with a large number of lipids and hemosiderin, showed that phagocytic cells have all the signs of fibroblasts: oval nuclei, an expanded eidoplasmic reticulum and a perinuclear arrangement of fibrillar structures.

Differential diagnosis. Differentiate dermatofibromu follows from the lipoma, pigment nevus.

Treatment of dermatofibroma. Conduct a surgical (electroexcision) excision of the tumor. Into the focus can be administered corticosteroids.

[1], [2], [3]