Dermatofibrosarcoma protuberans

	WikiDoc Resources for Dermatofibrosarcoma protuberans
Articles
Most recent articles on Dermatofibrosarcoma protuberans Most cited articles on Dermatofibrosarcoma protuberans Review articles on Dermatofibrosarcoma protuberans Articles on Dermatofibrosarcoma protuberans in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Dermatofibrosarcoma protuberans Images of Dermatofibrosarcoma protuberans Photos of Dermatofibrosarcoma protuberans Podcasts & MP3s on Dermatofibrosarcoma protuberans Videos on Dermatofibrosarcoma protuberans
Evidence Based Medicine
Cochrane Collaboration on Dermatofibrosarcoma protuberans Bandolier on Dermatofibrosarcoma protuberans TRIP on Dermatofibrosarcoma protuberans
Clinical Trials
Ongoing Trials on Dermatofibrosarcoma protuberans at Clinical Trials.gov Trial results on Dermatofibrosarcoma protuberans Clinical Trials on Dermatofibrosarcoma protuberans at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Dermatofibrosarcoma protuberans NICE Guidance on Dermatofibrosarcoma protuberans NHS PRODIGY Guidance FDA on Dermatofibrosarcoma protuberans CDC on Dermatofibrosarcoma protuberans
Books
Books on Dermatofibrosarcoma protuberans
News
Dermatofibrosarcoma protuberans in the news Be alerted to news on Dermatofibrosarcoma protuberans News trends on Dermatofibrosarcoma protuberans
Commentary
Blogs on Dermatofibrosarcoma protuberans
Definitions
Definitions of Dermatofibrosarcoma protuberans
Patient Resources / Community
Patient resources on Dermatofibrosarcoma protuberans Discussion groups on Dermatofibrosarcoma protuberans Patient Handouts on Dermatofibrosarcoma protuberans Directions to Hospitals Treating Dermatofibrosarcoma protuberans Risk calculators and risk factors for Dermatofibrosarcoma protuberans
Healthcare Provider Resources
Symptoms of Dermatofibrosarcoma protuberans Causes & Risk Factors for Dermatofibrosarcoma protuberans Diagnostic studies for Dermatofibrosarcoma protuberans Treatment of Dermatofibrosarcoma protuberans
Continuing Medical Education (CME)
CME Programs on Dermatofibrosarcoma protuberans
International
Dermatofibrosarcoma protuberans en Espanol Dermatofibrosarcoma protuberans en Francais
Business
Dermatofibrosarcoma protuberans in the Marketplace Patents on Dermatofibrosarcoma protuberans
Experimental / Informatics
List of terms related to Dermatofibrosarcoma protuberans

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: Kiran Singh, M.D. [2], Faizan Sheraz, M.D. [3]

Synonyms and keywords:: Darier-Ferrand tumor, Darier-Hoffmann tumor, dermatofibrosarcoma, DFSP

Overview

Dermatofibrosarcoma protuberans (DFSP) is a rare neoplasm of the dermis layer of the skin, and is classified as a sarcoma. In many respects, the disease behaves as a benign tumor, but in 2-5% of cases it can metastasize, so it should be considered to have malignant potential.

Over 95% of DFSP tumors have the chromosomal translocation t(17;22). The translocation fuses the collagen gene (COL1A1) with the platelet-derived growth factor gene. The fibroblast, the cell of origin of this tumor, expresses the fusion gene in the belief that it is collagen. However the resulting fusion protein is processed into mature platelet-derived growth factor which is a potent growth factor. Fibroblasts contain the receptor for this growth factor. Thus the cell "thinks" it is producing a structural protein, but in fact produces a self-stimulatory growth signal. The cell divides rapidly and a tumor forms.

Pathophysiology

Dermatofibrosarcoma protuberans is associated with a rearrangement (translocation) of genetic material between chromosomes 17 and 22. This translocation, written as t(17;22), fuses part of the COL1A1 gene from chromosome 17 with part of the PDGFB gene from chromosome 22. The translocation is found on one or more extra chromosomes that can be either the normal linear shape or circular. When circular, the extra chromosomes are known as supernumerary ring chromosomes. Ring chromosomes occur when a chromosome breaks in two places and the ends of the chromosome arms fuse together to form a circular structure. Other genes from chromosomes 17 and 22 can be found on the extra chromosomes, but the role these genes play in development of the condition is unclear. The translocation is acquired during a person's lifetime and the chromosomes containing the translocation are present only in the tumor cells. This type of genetic change is called a somatic mutation. In normal cells, the COL1A1 gene provides instructions for making part of a large molecule called type I collagen, which strengthens and supports many tissues in the body. The PDGFB gene provides instructions for making one version (isoform) of the platelet derived growth factor (PDGF) protein. By attaching to its receptor, the active PDGFB protein stimulates many cellular processes, including cell growth and division (proliferation) and maturation (differentiation). The abnormally fused COL1A1-PDGFB gene provides instructions for making an abnormal combined (fusion) protein that researchers believe ultimately functions like the PDGFB protein. The gene fusion leads to the production of an excessive amount of protein that functions like the PDGFB protein. In excess, this fusion protein stimulates cells to proliferate and differentiate abnormally, leading to the tumor formation seen in dermatofibrosarcoma protuberans. The COL1A1-PDGFB fusion gene is found in more than 90 percent of dermatofibrosarcoma protuberans cases. In the remaining cases, changes in other genes may be associated with this condition. These genes have not been identified^[1].

Classification

There are several variants of dermatofibrosarcoma protuberans in which different cell types are involved in the tumor. Bednar tumors, often called pigmented dermatofibrosarcoma protuberans, contain dark-colored (pigmented) cells called melanin-containing dendritic cells. Myxoid dermatofibrosarcoma protuberans tumors contain an abnormal type of connective tissue known as myxoid stroma. Giant cell fibroblastoma, which is sometimes referred to as juvenile dermatofibrosarcoma protuberans because it typically affects children and adolescents, is characterized by giant cells in the tumor.