title: The tip of the iceberg: a giant pelvic atypical lipoma presenting as a sciatic hernia.
abstract: BACKGROUND
  This case report highlights two unusual surgical phenomena: lipoma-like well-differentiated liposarcomas and sciatic hernias. It illustrates the need to be aware that hernias may not always simply contain intra-abdominal viscera.
  
  
  METHODS
  A 36 year old woman presented with an expanding, yet reducible, right gluteal mass, indicative of a sciatic hernia. However, magnetic resonance imaging demonstrated a large intra- and extra-pelvic fatty mass traversing the greater sciatic foramen. The tumour was surgically removed through an abdomino-perineal approach. Subsequent pathological examination revealed an atypical lipomatous tumour (synonym: lipoma-like well-differentiated liposarcoma). The patient remains free from recurrence two years following her surgery.
  
  
  CONCLUSIONS
  The presence of a gluteal mass should always suggest the possibility of a sciatic hernia. However, in this case, the hernia consisted of an atypical lipoma spanning the greater sciatic foramen. Although lipoma-like well-differentiated liposarcomas have only a low potential for recurrence, the variable nature of fatty tumours demands that patients require regular clinical and radiological review.
authors.affiliation: Department of General Surgery, St, John's Hospital at Howden, Livingston, NHS Lothian-University Hospitals Division, UK.
authors.forename: Richard J E
authors.initials: RJ
authors.lastname: Skipworth
authors.forename: Graeme H M
authors.initials: GH
authors.lastname: Smith
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Stewart
authors.forename: David N
authors.initials: DN
authors.lastname: Anderson