Gastrointestinal tumors in transplantation: Two case reports and review of literature

BACKGROUND Gastrointestinal stromal tumors(GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. As most of them harbor a KIT mutation(75%),selective kinase inhibitors are the therapeutic option and show a sustained objective response among patients with metastatic or unresectable GISTs. A wellknown higher risk of neoplasm has been described among renal transplant recipients(RTRs). Nevertheless,only few cases of GIST onset among transplant patients have been reported in the literature.CASE SUMMARY Here,we describe 2 cases of gastric GIST occurring during the follow-up of RTRs. We also review the existing literature concerning GIST occurrence in transplant patients. In total and in association with our 2 cases,16 patients have been reported. The median age was 59.5 years and 69% were male. With a median tumor size of 45 mm,no patient displayed metastatic dissemination at diagnosis.Time from transplantation to diagnosis was highly variable between 5 mo and 21 years. Histopathological data mostly revealed high risk of progression(43%). Death increased to 29% during follow-up. Surgical treatment was systematically performed when the tumor was operable(94%). The use of adjuvant therapy was uncommon(19%).CONCLUSION GISTs represent rare but potentially severe malignant complication among transplant patients.