title: Successful outcome after laparoscopic surgery for sporadic colonic desmoid tumor with β-catenin mutation: a case report.
abstract: BACKGROUND
  Desmoid tumors (also called aggressive fibromatosis) are histologically benign, but have a strong tendency to recur locally after resection. They are rare neoplastic tumors that may occur sporadically or in association with familial adenomatous polyposis caused by a germline mutation in the adenomatous polyposis coli gene. The etiology of desmoid tumors is unknown, but their association with a history of abdominal surgery, trauma, and estrogen therapy is well known.
  
  
  METHODS
  A 36-year-old Asian woman was referred complaining of an abdominal tumor. She had no history of familial adenomatous polyposis, abdominal surgery, trauma or pregnancy. A laparoscopy-assisted right hemicolectomy with a minilaparotomy was conducted for resection of her right-side colon and the anterior wall of her duodenum. The histopathological diagnosis was a desmoid tumor that grew from the transverse mesocolon. Mutational analysis indicated a mutation of the β-catenin gene (CTNNB1), consisting of a substitution of threonine for alanine at codon 41. The patient has been followed postoperatively for more than 3 years without any sign of recurrence.
  
  
  CONCLUSIONS
  We report a case of sporadic colonic desmoid tumor which was resected by laparoscopic surgery. A successful outcome was achieved because there has been no local recurrence for more than 3 years. The tumor grew from the transverse mesocolon, and harbored a mutation of the CTNNB1 gene. Mutational analysis of CTNNB1 gene may play an important role as a prognostic marker of desmoid tumors.
authors.affiliation: Department of Surgery, Kyoto University Graduate School of Medicine, 54 Shogoin- Kawara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. kkawada@kuhp.kyoto-u.ac.jp.
authors.forename: Shutaro
authors.initials: S
authors.lastname: Gunji
authors.forename: Kenji
authors.initials: K
authors.lastname: Kawada
authors.forename: Mayumi
authors.initials: M
authors.lastname: Kawada
authors.forename: Suguru
authors.initials: S
authors.lastname: Hasegawa
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Sakai