title: Neoadjuvant imatinib in a gastrointestinal stromal tumor of the rectum: report of a case.
abstract: Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract, and of these, GISTs involving the rectum are uncommon. This report describes a case of effective neoadjuvant therapy for a rectal GIST expressing the c-kit gene, where a laparoscopic ultralow anterior resection was successfully performed, thus preserving the anus. A 57-year-old woman visited our hospital due to constipation and was found by a digital examination to have a soft mass on the right wall of the rectum. Computed tomography revealed an 8.0 x 5.0-cm mass with an unclear margin adjacent to the rectum. A biopsy specimen was positive for CD34 and the c-kit gene product, but it was not positive for smooth muscle actin or S-100 protein, and thus the tumor was diagnosed as GIST. An abdominoperineal resection is generally essential for large rectal GISTs; however, she refused this operation. Neoadjuvant treatment with Imatinib decreased the tumor size (4.0 x 3.5 cm) and the anus was preserved by a laparoscopic ultralow anterior resection with direct coloanal anastomosis. She had no evidence of disease for 24 months postoperatively. To preserve the anus, a rectal GIST expressing the c-kit gene is best treated with Imatinib as neoadjuvant therapy.
authors.affiliation: Department of Surgery, Tonan Hospital, N1W6, Chuo-ku, Sapporo, Hokkaido, 060-0001, Japan.
authors.forename: Yuma
authors.initials: Y
authors.lastname: Ebihara
authors.forename: Shunichi
authors.initials: S
authors.lastname: Okushiba
authors.forename: You
authors.initials: Y
authors.lastname: Kawarada
authors.forename: Shuji
authors.initials: S
authors.lastname: Kitashiro
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Katoh
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kondo
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage*; D001549:Benzamides; D003082:Colectomy; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis / Q000188:drug therapy* / Q000601:surgery; D006801:Humans; D000068877:Imatinib Mesylate; D010535:Laparoscopy; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D010879:Piperazines / Q000008:administration & dosage*; D011743:Pyrimidines / Q000008:administration & dosage*; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000601:surgery
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate