title: Secondary recurrent multiple EGIST of the mesentary: A case report and review of the literature.
abstract: BACKGROUND
  Gastrointestinal stromal tumors (GISTs) are rare intra-abdominal tumors arising from mesenchymal stromal cells. EGISTs are mesenchymal tumors that originate outside the GI tract and tend to have similar characteristics to GISTs. To the best of our knowledge, few cases of long standing recurrent EGIST have been reported.
  
  
  METHODS
  We present the case of a rare recurrent EGIST in the mesentery of a 39 year old female patient. The tumor was symptomatic at the time of complaint and measured 8.4cm×7.7cm×7.6cm. Histological analysis revealed a spindled pattern with fusiform cells arranged in long fascicles and little atypia. Immunochemistry showed positivity for CD117 and was negative for CD34, S-100, Desmin, and MSA. B-catenin was weakly positive. A Ki-67 staining shows approximately 5% positivity revealing a low proliferative rate. The patient was doing well postoperatively and was discharged on 400mg imanitib regimen.
  
  
  CONCLUSIONS
  While GISTs are the most common tumors of the GI tract, recurrent EGISTs of the mesentery are extremely rare. Factors that indicate poor prognosis include tumor size greater than 5cm, mitotic rate greater than 1-5/10 HPF, presence of tumor necrosis or metastasis and most recently the c-kit mutation. Our patient had a very long time between recurrence of disease.
  
  
  CONCLUSIONS
  The current literature on EGISTs is limited. Our patient presents a very interesting case due to the time elapsed between disease recurrence and lack of metastasis or excessive growth.
authors: Department of Surgery, Boston University School of Medicine, Boston, MA 02118, United States.
authors: Ilona D
authors: ID
authors: Goukassian
authors: S R
authors: SR
authors: Kussman
authors: Y
authors: Y
authors: Toribio
authors: Jennifer E
authors: JE
authors: Rosen