Two different mutational types of familial gastrointestinal stromal tumors: Two case reports

BACKGROUND Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract, and cases of GISTs tend to be of the disseminated type, with a global incidence of 10 to 15 cases/million each year. The rarer familial GISTs, which often represent a population, differ in screening, diagnosis, and treatment. Familial GISTs include primary familial GISTs with predominantly KIT/PDGFRA mutations and wild-type GISTs. However, whether the same genetic family has different phenotypes has not been reported. CASE SUMMARY We report two cases of rare GISTs in the same family: A male patient with the V561D mutation in exon 12 of the PDGFRA gene, who has been taking the targeted drug imatinib since undergoing surgery, and a female patient diagnosed with wild-type GIST, who has been taking imatinib for 3 years since undergoing surgery. The favorable prognosis of these patients during the 7-year follow-up period validates the accuracy of our treatment strategy, and we have refined the entire process of diagnosis and treatment of familial GISTs in order to better manage this rare familial disease. CONCLUSION Different mutation types of familial GISTs in the same family are very rare, thus it is very important to make the correct diagnosis and treatment strategies according to the results of molecular detection for the management of familial GISTs.