When neoplasia is detected in the donor before or immediately after transplantation, histological examination and ancillary studies such as immunohistochemistry can help to compare the pathology with any subsequent tumours developing in the recipient or recipients. For example, identification of a lung carcinoma in the donor needs detailed investigation of the tumour (histology, grade and immunohistochemical profile) and either graft removal or careful follow up of the recipients. If a tumour develops in one or more of the recipients of organs from this donor, the morphological comparison of the tumour in the donor and the tumour arising in the recipients can confirm the donor origin of the tumour.
