A case of cutaneous endometriosis developed on an abdominal scar. 
Endometriosis is characterized by the presence of an ectopic endometrial tissue.  It affects between 1% and 5% of women in reproductive age.  Its main clinical symptoms are dysmenorrhoea and infertility.  Among women having had abdominal surgery for any gynecological reason, the prevalence of endometriosis is between 15% and 50%.  We report the case of a 15 year-old patient who underwent surgery twice : once for appendicitis two years before and once for acute salpingitis and tubo-ovarian abscesses one year before.  Laparotomy was performed by Pfannenstiel incision.  The post operative course was uneventful.  The patient reported the gradual emergence of two bluish nodes on the abdominal scar.  These nodules became painful and turgid during the menstrual period.  She also reported the issue of blood from the abdominal scar during menstruation.  The abdominal examination, performed during the menstrual period, showed a scar of good quality and two regular shiny and bluish cutaneous nodules measuring 1 cm in size.  These elements were firm and painless.  An endometriosis node on the scar of laparotomy was suspected.  Surgery was performed in order to remove both nodules.  At surgery the depth of nodules reached the top of the abdominal fascia of the major rights.  The content of these nodules was chocolate brown.  The histo-pathological examination confirmed that these nodules contained ectopic endometrial tissue.  The etiopathogeny of endometriosis is still a subject of debate.  This case illustrates the possibility of occurrence of endometriosis on abdominal scars after laparotomy: an unusual location.