De novo malignant melanoma occurred in renal allograft: DNA typing to determine the origin of the tumour

Abstract

Abstract Malignant diseases are considered as great challenges in clinical transplantation. It is well known that the incidence of malignancy is higher in the transplanted population if compared with the normal population. It is important to distinguish between neoplastic diseases originating from pre-existing lesions in the transplanted organs and de novo graft tumours. Post-transplant malignancy of donor origin is a rare complication of organ transplantation, most likely transmitted as micrometastases within the parenchyma of the donor organ or from circulating tumour cells contained within the organ. Malignant melanoma, although its incidence is rather low, is one of the most common donor-derived tumour inadvertently transplanted, comprising 28% of donor transmitted tumours. Malignant melanoma in the graft without dermatological localisation is extremely rare. We report a case of de novo melanoma occurring in the allograft, where transmission from the donor was excluded by DNA (desoxyribonucleic acid) investigation. We did not find any data in the literature where a malignant melanoma occurred after transplantation in the transplanted kidney without any skin lesions and the donor origin was excluded. We draw attention to the importance of the DNA typing in case of tumours occurring in immunosuppressed patients.