title: Gastrointestinal stromal tumor of the vermiform appendix mimicking Meckel's diverticulum: Case report with literature review.
abstract: BACKGROUND
  Gastrointestinal stromal tumors (GISTs) of the appendix are extremely rare. To date, only 15 cases have been reported in the English literature. Here, we present a new case of an appendiceal GIST with appendicitis.
  
  
  METHODS
  A 68-year-old man who complained of right lower abdominal tenderness underwent surgery for a cystic mass mimicking Meckel's diverticulum. Laparoscopy revealed a mass protruding from the proximal appendix with distal appendicitis. Complete resection with adequate margins was performed. Histology showed a spindle cell GIST without mitotic activity as well as a strong expression of CD117 and CD34.
  
  
  CONCLUSIONS
  Primary appendiceal GIST occur at a very low rate and their symptoms are nonspecific. Accordingly, rare tumors of appendix including GISTs should be considered in the differential diagnosis of atypical symptoms or image findings.
authors.affiliation: Department of Surgery, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, 130 Dongduk-ro, Jung-gu, Daegu, 700-721, South Korea.
authors.forename: Jae Min
authors.initials: JM
authors.lastname: Chun
authors.affiliation: Department of Surgery, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, 130 Dongduk-ro, Jung-gu, Daegu, 700-721, South Korea. Electronic address: ttangguri@hanmail.net.
authors.forename: Kyoung Hoon
authors.initials: KH
authors.lastname: Lim
keywords: Appendix; CD117; CD34; Gastrointestinal stromal tumor; Low risk