Transmission of Tumor Cells with a Non-tumor Bearing Allograft

Transmission of cancer by a tumor-bearing allograft is rare. Recently Barozzi et al. (Nat Med 2003) documented transmission of isolated tumor cells (Kaposi sarcoma) during the transplantation procedure. We report on a 40-year-old caucasian female without a history of previous malignancy who received a first cadaveric renal allograft from a 63-year-old male donor. The donor (former heavy smoker) died from a intracerebral hemorrhage. At the time of organ harvesting no evidence of malignancy was notable in the donor. 10 months post transplant the recipient experienced severe back pain due to an osteolytic lesion of the 10th thoracic vertebrae. An intensive clinical workup disclosed five liver metastasis and osteolytic metastasis of the scull. CT scan and bronchoscopy of the recipient′s lung were negative. In addition repeated imaging of the allograft (ultrasonography and MRI) was completely negative. A biopsy of one of the liver lesions revealed a small cell carcinoma (synaptophysine, cytokeratine and neuron specific enolase positivity by immunohistochemistry) with no primary detectable in the recipient. DNA fingerprinting analysis of the malignant cells documented the Y-chromosome and a similar DNA pattern of both, the resected renal allograft and the biopsy specimen of the liver mass. Lamination of the resected renal allograft showed no macroscopic or microscopic evidence of malignancy. After a follow up of more than one year (after cessation of immunosuppression) the liver metastases completely vanished and the vertebral bone is remineralising. Circulating tumor cells were initially detectable in the recipient (preproGRP mRNA in recipient′s blood) but absent after cessation of immunosuppression. Rejection of the tumor (expressing HLA class I antigens) is a plausible explanation for this finding. In conclusion we report on the transmission of isolated malignant cells (small cell carcinoma), similar to the report of Barozzi, by the transplantation procedure. This finding is of particular relevance in the view of an ageing donor population.