Gonadal tumors developed from consecutively transplanted spleens bearing gonad implants

This study was conducted by consecutively transplanting spleens, which had gonads implanted previously. A total of 84 cases for infantile testicles and 106 cases for ovarian follicles were performed. In the case of ovarian implants, the results were determined by the total number of follicle implants. A modified spleen transplantation technique called double implantation of ovarian follicles was applied to increase the amount of the implants. In this technique, an extra spleen is implanted into the potential donor so that the ovarian follicles can be implanted to two different spleens, doubling the amount of implants. Through consecutive spleen transplantation, we observed the results beyond a typical rat's life span. In many of these cases, we found more aggressive forms of malignant tumor, seminoma and dysgerminoma. We present the results and discuss possible pathogenic mechanisms of tumor formation.