title: Histologic Features Associated with Deep Invasion in Dermatofibrosarcoma Protuberans.
abstract: BACKGROUND
  Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing cutaneous tumor that can invade the subcutaneous tissue, muscle tissue, and even bone.
  
  
  OBJECTIVE
  To identify histologic features associated with greater depth of invasion, i.e., local aggressiveness, in DFSP.
  
  
  METHODS
  We analyzed associations between histologic features of DFSP (e.g., type of subcutaneous invasion, histologic pattern, cell type, areas of fibrosarcoma) and the presence and absence of muscle fascia involvement.
  
  
  RESULTS
  We studied 155 cases of DFSP. The following histologic characteristics were significantly associated with involvement of the muscle fascia: the presence of a sheetlike pattern, a high degree of cellular pleomorphism, and more than 1 mitotic figure. The tumor did not extend beyond the subcutaneous tissue in the majority of cases (62.6%), but there was involvement of the fascia or galea aponeurotica in 17 cases (11%) and of the muscle tissue in 36 cases (23.2%).
  
  
  CONCLUSIONS
  Histologic patterns, degree of pleomorphism, and number of mitotic figures are important predictors of deep invasion (fascia or muscle) in DFSP; these layers can be involved in up to 30% of cases.
authors.affiliation: Servicio de Dermatología, Instituto Valenciano de Oncología, Valencia, España. Electronic address: cserraguillen@gmail.com.
authors.forename: C
authors.initials: C
authors.lastname: Serra-Guillén
authors.affiliation: Servicio de Dermatología, Instituto Valenciano de Oncología, Valencia, España.
authors.forename: B
authors.initials: B
authors.lastname: Llombart
authors.affiliation: Servicio de Dermatología, Instituto Valenciano de Oncología, Valencia, España.
authors.forename: E
authors.initials: E
authors.lastname: Nagore
authors.affiliation: Servicio de Dermatología, Instituto Valenciano de Oncología, Valencia, España.
authors.forename: C
authors.initials: C
authors.lastname: Guillén
authors.affiliation: Servicio de Dermatología, Instituto Valenciano de Oncología, Valencia, España.
authors.forename: C
authors.initials: C
authors.lastname: Requena
authors.affiliation: Servicio de Dermatología, Instituto Valenciano de Oncología, Valencia, España.
authors.forename: S
authors.initials: S
authors.lastname: Kindem
authors.affiliation: Servicio de Dermatología, Instituto Valenciano de Oncología, Valencia, España.
authors.forename: N
authors.initials: N
authors.lastname: Rivas
authors.affiliation: Servicio de Dermatología, Instituto Valenciano de Oncología, Valencia, España.
authors.forename: L
authors.initials: L
authors.lastname: Calomarde
authors.affiliation: Servicio de Dermatología, Instituto Valenciano de Oncología, Valencia, España.
authors.forename: O
authors.initials: O
authors.lastname: Sanmartín
mesh_terms: D018223:Dermatofibrosarcoma / Q000473:pathology*; D006801:Humans; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology*
keywords: Características histológicas; Dermatofibrosarcoma protuberans; Histologic features; Infiltración; Invasion