Gastrointestinal Stromal Tumors with Unusual Localization: Report of Three Cases with a Brief Literature Review

Laparoscopic pancreas-preserving subtotal duodenectomy for gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) of the duodenum are rare neoplasms. The optimal surgical procedure is debated and several options ranging from limited resections to pancreaticoduodenectomy have been reported. The laparoscopic approach has been validated for gastric GISTs, but it does not yet represent a standard technique for tumors of the duodenum. We report the case of a localized duodenal GIST that was successfully treated by totally laparoscopic pancreas-preserving subtotal duodenectomy. This procedure may represent a feasible and effective treatment option for localized GISTs of the duodenum. Large series with long-term follow-up are needed.

Gastrointestinal stromal tumors: a review of case reports, diagnosis, treatment, and future directions

Gastrointestinal stromal tumor (GIST) is a nonepithelial, mesenchymal tumor first described by Mazur and Clark in 1983. Since then, its molecular biology has been studied in great detail. Special interest in the role of tyrosine kinase in its regulation has been the target by different drug research. Mutation in c-kit exons 9, 11, 13, 17 and PDGFRA mutation in exons 12, 14, 18 are responsible for activation of gene signaling system resulting in uncontrolled phosphorylation and tissue growth. However, 5 to 15% of GISTs does not harbor these mutations, which raises additional questions in another alternate signaling pathway mutation yet to be discovered. Diagnosis of GISTs relies heavily on KIT/CD117 immunohistochemical staining, which can detect most GISTs except for a few 3% to 5% that harbors PDGFRA mutation. Newer staining against PKC theta and DOG-1 genes showed promising results but are not readily available. Clinical manifestation of GISTs is broad and highly dependent on tumor size. Surgery still remains the first-line treatment for GISTs. The advancement of molecular biology has revolutionized the availability of newer drugs, Imatinib and Sunitinib. Together with its advancement is the occurrence of Imatinib/Sunitinib drug resistance. With this, newer monoclonal antibody drugs are being developed and are undergoing clinical trials to hopefully improve survival in patients with GISTs.