Case report: Donor origin Mullerian clear cell carcinoma in male kidney allograft recipient (2023)

This is an example of a donor-derived, not a donor-transmitted, tumor- i.e., it is a de novo posttransplant tumor that arose from donor cells. This case is unique in that Mullerian tumors are predominantly seen within females, and this male patient received a transplant kidney from his father. The allograft itself did not appear to be involved, with the tumor clinically presenting with symptoms suggesting an acute appendicitis. The tumor was in the periappendiceal and intraperitoneal regions, with lymphadenopathy and ascites. The authors note that the clear cell features of the tumor led to an original misdiagnosis of renal cell carcinoma. They recommend that the histologic diagnosis always be confirmed by appropriate pathological workup (e.g., immunohistochemistry +/- appropriate molecular studies). They hypothesize that the tumor arose from ectopic Mullerian cells located in the graft in tissue adjacent to and transplanted with the kidney (Mullerian tumors can rarely arise in males, more often in the vesicourethral region; they note only 5 reported cases of upper urinary tract Mullerian carcinomas in males). They separately observe that it is worthwhile examining donor: recipient origin in tumors localized to the allograft even in late-arising cases, and point out that a donor origin renal cell carcinoma in the allograft is a Stage I tumor, but a recipient origin renal cel carcinoma in the allograft would be a Stage IV tumor. Treatment, including a discussion of the use of immune checkpoint inhibitors, is discussed. Unfortunately in this patient, chemotherapy including immune checkpoint inhibitors was unsuccessful and he succumbed to this aggressive tumor. No additional information is provided regarding the donor.