Clinical manifestations of transmitted malignancies may be variable depending on the type of tumour. In the context of solid organ transplantation, the identification of a malignancy in the transplanted organ, with or without extra graft involvement, should raise the suspicion of a transmitted malignancy. However, some reports have described a different clinical picture where the transmitted malignant tumour does not involve the allograft itself.
Temporal sequence should be reasonable according to the tumour type under study. Most (but not all) transmitted tumours appear within the first 14 months after transplantation. Therefore, it is unlikely that an aggressive tumour diagnosed in a recipient 5 years after transplantation is donor-transmitted. Other things to consider might be sex-or age-discordant tumours, metastatic disease with no known primary site, or CNS tumour appearing outside of the CNS (80). A previous description of similar transmissions may help support the suspicion and correct assessment of a case involves the analysis of the literature to understand whether the same tumour type has been transmitted before and the clinical presentation and course consequent to transmission. Registry reports and case reports provide information regarding the type of transmission and the methodology followed for the assessment of imputability.
