Mixed epithelial and stromal tumor after pediatric kidney transplant.

MEST of the kidney are a benign group of tumors with very rare incidence of malignant transformation. First described in 1998, this tumor has never been reported in a transplanted organ before. We present a unique case of de novo MEST in a donor kidney 4 years after transplant into a pediatric patient. Although removal of the lesions is curative without risking malignant transformation, in this case, surgical removal was not attempted to prevent reduction in transplant longevity. In this unique report of MEST in a transplanted kidney, we describe the patient/transplant outcomes without MEST resection.