Benign+Keloid


 * **Epidemiolgy:** || Keloids typically appear following some surgery or injury but sometimes appear spontaneously or from slight inflammation such as acne. Burns and piercings can also cause the formation of keloids.2 ||
 * **Etiology:** || There is no understanding why keloids form in some individuals and not others. Keloids are equally common in men and women, although incidence was higher in women in the past due to the higher percentage of women who had piercings. Keloids are more common in the middle ages and people with darker skin. In some cases, keloids are believed to be hereditary.2 ||
 * **Signs & Symptoms:** || Keloids show up as pink to red shiny, dome shaped bumps that can become large and unsightly. Aside from the cosmetic problems keloids can be itchy and painful to touch.2 ||
 * **Diagnostic Procedures:** || Keloids are diagnosed by their appearence.1 ||
 * **Histology:** || Keloids have a normal epidermal layer; abundant vasculature; increased mesenchymal density, as manifested by a thickened dermis; and increased inflammatory-cell infiltrate when compared with normal scar tissue. 1

The reticular layer of the dermis consists mainly of collagen and fibroblasts, and injury to this layer is thought to contribute to formation of keloids.1

Collagen bundles in the dermis of normal skin appear relaxed and in an unordered arrangement; collagen bundles are thicker and more abundant in keloids, yielding acellular, nodelike structures in the deep dermal region. 1

The most consistent histologic distinguishing characteristic of keloids is the presence of large, broad, closely arranged collagen fibers composed of numerous fibrils.1

 In addition to collagen, proteoglycans are another major extracellular matrix (ECM) component deposited in excess amounts in keloid scars.1 There are four histologic features that are consistently found in keloid specimens that are deemed pathognomonic for their diagnosis.1
 * the presence of keloidal hyalinized collagen
 * tonguelike advancing edge underneath normal-appearing epidermis and papillary dermis
 * horizontal cellular fibrous bands in the upper reticular dermis
 * prominent fascialike fibrous bands ||
 * **Lymph node drainage:** || Keloids are benign tumors which are cosmetically disfiguring. They can occur on any part of the body and do not travel by the lymphatic system ||
 * **Metastatic spread:** || Keloids are benign tumors. They can occur on any part of the body and do not travel by the lymphatic system. Metastases do not occur from keloids.2 ||
 * **Grading:** || There is no grading system for keloids.2 ||
 * **Staging:** || There is no staging system for keloid formations.2 ||
 * **Radiation side effects:** || The side effects of radiation therapy for keloids depend on location, but normally only include skin irritation. ||
 * **Prognosis:** || Keloids are not considered to be life threatening. ||
 * **Treatments:** || There are various treatments for keloids which include surgery, postoperative pressure, corticosteroid injections, laser treatments, and radiation therapy. 3 Typical radiation treatments include external kilovoltage or electron-beam radiation directed at the surgical bed within 24 to 72 hours after re-excision. 3 The re-excision, plus a 1 to 2 centimeter margin, is treated with 100 to 250 kV x-rays or 6 to 10 meV electrons (with 0.5 to 1.0 cm of bolus). 3 Doses of 9 to 16 Gy in three to four fractions are adequate for treatments begun within 72 hours of excision. 3 ||
 * **TD 5/5:** || There is no TD 5/5 associated with keloids. ||
 * **References:** || # Keloids. Medscape Reference. Available at: [|http://emedicine.medscape.com/article/1298013-overview#aw2aab6b2]. Accessed on: June 3, 2012.
 * 1) MedicineNet. Keloid. Available at: []. Accessed on July 5, 2012.
 * 2) Hoppe RT, Phillips TL, Mack III M. Leibel and Phillips Textbook of Radiation Oncology. 3rd ed. Philadelphia Pa: Elsevier Saunders; 2010. ||

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