title: Giant inframuscular lipoma disclosed 14 years after a blunt trauma: a case report.
abstract: BACKGROUND
  Lipoma is the most frequent benign tumor of the soft tissue. This lesion is often asymptomatic except in cases of enormous masses compressing nervous-vascular structures. Although the diagnosis is mostly clinical, imaging tools are useful to confirm the adipose nature of the lesion and to define its anatomic border. Sometimes, lipomas may be the result of a previous trauma, such as in this patient.
  
  
  METHODS
  A 45-year-old man presented at our institution with a giant hard firm mass in the upper external quadrant of the right buttock disclosed after a weight loss diet. Subsequent magnetic resonance imaging showed a giant adipose mass developed beneath the large gluteal muscle and among the fibers of the medium and small gluteal muscles. When questioned on his medical history, the patient reported a blunt trauma of the lower back 14 years earlier. He underwent surgery and histological examination confirmed a giant lipoma.
  
  
  CONCLUSIONS
  Lipomas might result from a previous trauma. It is hypothesized that the trigger mechanism is activated by cytokine and growth factors released after the trauma. We herein present an exceptional case of a giant post-traumatic lipoma which caused a painful compression on the right sciatic nerve.
authors.affiliation: Department of Surgery, Sapienza University of Rome, School of Medicine, St. Andrea Hospital, Rome, Italy. giuseppe.nigri@uniroma1.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nigri
authors.forename: Mario
authors.initials: M
authors.lastname: Dente
authors.forename: Stefano
authors.initials: S
authors.lastname: Valabrega
authors.forename: Giacomo
authors.initials: G
authors.lastname: Beccaria
authors.forename: Paolo
authors.initials: P
authors.lastname: Aurello
authors.forename: Francesco
authors.initials: F
authors.lastname: D'Angelo
authors.forename: Francesco
authors.initials: F
authors.lastname: Di Marzo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ramacciato