Donor-derived small cell lung carcinoma in a kidney transplant recipient

BACKGROUND: Transplantation of donor-derived malignancies during organ transplantation fortunately is very rare. Discontinuation of immunosuppressive medications under these circumstances has previously resulted in complete tumor rejection. Ectopic adrenocorticotropic hormone (ACTH) production may result in Cushing syndrome and is not an uncommon paraneoplastic feature of small cell carcinoma of the lung. Theoretically, in the organ transplantation setting, the resulting high cortisol levels could suppress a tumor-rejection immune response. However, to the authors' knowledge, no such clinical scenario has been described in the literature published to date. METHODS: A 25-year-old living related kidney transplant recipient presented with Cushing syndrome 32 months after transplantation. The donor had been diagnosed with small cell carcinoma of the lung 22 months earlier. On further evaluation, the kidney recipient was diagnosed with donor-derived small cell lung carcinoma of the transplanted kidney. She was found to have extensive disease involving the liver and retroperitoneum. Despite discontinuation of immunosuppressive medications, the disease progressed and cortisol levels remained elevated during 6 weeks of observation. RESULTS: The patient received six cycles of cisplatin and etoposide, which resulted in resolution of her hypercortisolemia and a complete remission of her donor-derived small cell carcinoma. At last follow-up, she was 12 months from completing her therapy and continued in complete remission. CONCLUSIONS: Donor-derived small cell carcinoma and ectopic ACTH production can occur in a patient after kidney transplantation.