title: Para-iliac actinomycetoma presenting as sarcoma, a late complication of appendicitis: A case report.
abstract: BACKGROUND
  Actinomycosis is known to mimic several types of neoplasms, leading to morbid surgical interventions.
  
  
  METHODS
  We report the particular case of an extensive right para-iliac actinomycetoma presenting as a sarcoma, which to our knowledge has not yet been described in the literature, in a patient with previous ruptured appendicitis. Thanks to the collaborative work between the orthopedic and general surgeons, pathologist and microbiologist, the diagnosis of actinomycosis was made pre-operatively, saving this 15-year-old patient from a tumor resection protocol.
  
  
  CONCLUSIONS
  Actinomycetomas have often been reported to present in the same way as several abdominal and gynecological neoplasms, and on rare occasions been described as mimicking other soft-tissue sarcomas, leading to unnecessary morbid tumor resection protocols. The most common cause of abdominal actinomycosis is perforated appendicitis, and may present several years later.
  
  
  CONCLUSIONS
  While faced with a soft tissue mass transgressing tissue planes and possibly extending to the region of the right lower quadrant, especially with a history of previous perforated appendicitis, one should consider the possibility of an abscess caused by pathogens of intestinal origin, including the gram positive anaerobe Actinomycosis israelii. Failure to actively search for this pathogen, which is not detectable with routine staining techniques and may take up to 1-2 weeks to isolate, may lead to unnecessary morbid surgical procedures.
authors.affiliation: Hôpital Sainte-Justine, Montréal, QC, Canada; Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada; Université de Montréal, Montréal, QC, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Navarre
authors.affiliation: Hôpital Sainte-Justine, Montréal, QC, Canada; Université de Montréal, Montréal, QC, Canada. Electronic address: marie-andree_cantin@ssss.gouv.qc.ca.
authors.forename: Marie-Andrée
authors.initials: MA
authors.lastname: Cantin
authors.affiliation: Hôpital Sainte-Justine, Montréal, QC, Canada; Hôpital Maisonneuve-Rosemont, Montréal, QC, Canada; Université de Montréal, Montréal, QC, Canada.
authors.forename: Marc H
authors.initials: MH
authors.lastname: Isler
keywords: Actinomyces; Actinomycetoma; Actinomycosis; Actinomycosis israelii; Infection; Sarcoma