Benign fibrous histiocytomas (also known as "Dermal dendrocytoma," "Dermatofibroma," "Fibrous dermatofibroma," "Fibrous histiocytoma", "Fibroma simplex", "Nodular subepidermal fibrosis", and "Sclerosing hemangioma") are benign skin growths.

Presentation

Dermatofibromas are hard papule

Papule

A papule is a circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to 1 cm.With regard to the quote "...varying in size from a pinhead to 1cm," depending on which text is referenced, some authors state the cutoff between a papule and a plaque as 0.5cm,...

s (rounded bumps) that may appear in a variety of colors, usually brownish to tan. Although typical dermatofibromas cause little or no discomfort, itching and tenderness can occur. Some physicians and researchers believe dermatofibromas form as a reaction to previous injuries such as insect bites or thorn pricks. They are composed of disordered collagen

Collagen

Collagen is a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of mammals. It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content...

 laid down by fibroblasts. In rare cases, basal cell carcinoma

Basal cell carcinoma

Basal-cell carcinoma is the most common type of skin cancer. It rarely metastasizes or kills. However, because it can cause significant destruction and disfigurement by invading surrounding tissues, it is still considered malignant. Statistically, approximately 3 out of 10 Caucasians may develop a...

 may develop in a dermatofibroma.

They are usually found on the leg.

Deep penetrating dermatofibroma may be difficult to distinguish, even histologically, from rare malignant fibrohistocytic tumours like dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans is a very rare tumor. It is a rare neoplasm of the dermis layer of the skin, and is classified as a sarcoma. There is only about 1 case per million per year. DFSP is a fibrosarcoma, more precisely a cutaneous soft tissue sarcoma...

.

Dermatofibromas occur most often in women; the male to female ratio is about 1:4.

Immunohistochemical staining

Neoplasm	CD34 CD34 CD34 molecule is a cluster of differentiation molecule present on certain cells within the human body. It is a cell surface glycoprotein and functions as a cell-cell adhesion factor. It may also mediate the attachment of stem cells to bone marrow extracellular matrix or directly to stromal cells...	Stromelysin-3	Factor XIIIa
Dermatofibroma	+	+	+
Dermatofibrosarcoma protuberans Dermatofibrosarcoma protuberans Dermatofibrosarcoma protuberans is a very rare tumor. It is a rare neoplasm of the dermis layer of the skin, and is classified as a sarcoma. There is only about 1 case per million per year. DFSP is a fibrosarcoma, more precisely a cutaneous soft tissue sarcoma...	+	-	-

See also

• Dermatology
  Dermatology
  Dermatology is the branch of medicine dealing with the skin and its diseases, a unique specialty with both medical and surgical aspects. A dermatologist takes care of diseases, in the widest sense, and some cosmetic problems of the skin, scalp, hair, and nails....
  
  
• Seborrheic keratosis
  Seborrheic keratosis
  A seborrheic keratosis is a noncancerous benign skin growth that originates in keratinocytes. Like liver spots, seborrheic keratoses are seen more often as people age. In fact they are sometimes humorously referred to as the "barnacles of old age". They appear in various colors, from light tan to...
  
  
• Acrochordon
  Acrochordon
  An acrochordon An acrochordon An acrochordon (plural acrochorda, and also known as a (cutaneous) skin tag, or fibroepithelial polyp, is a small benign tumour that forms primarily in areas where the skin forms creases, such as the neck, armpit, and groin. They may also occur on the face, usually on...
  
  , also called skin tags
• List of cutaneous conditions