De novo hepatocellular carcinoma in a non-cirrhotic allograft 27 years after liver transplantation: A case report.

Hepatocellular carcinoma recurrence after liver transplantation is a well-known complication but the development of de novo hepatocellular carcinoma in non-cirrhotic allograft with no previous history of hepatic malignancy either in the donor or the recipient is extremely rare. A 33-year-old man underwent deceased donor liver transplantation due to HBV-HDV cirrhosis in 1991. The donor was healthy, with negative viral serology. Pretransplant assessment and explant liver pathology revealed no tumor. He developed an 8 cm mediastinal thymus cancer in 2014, a chronic myeloid leukemia in 2015 and a 16 mm renal cell carcinoma in 2017. After 27 years, in 2018, his routine follow-up sonography showed incidentally a 37 mm hepatic nodule in segment VII which revealed after percutaneous liver guided biopsy a hepatocellular carcinoma. As no extra hepatic metastasis was noted, segmentectomy was done. The pathological report confirmed a moderately differentiated hepatocellular carcinoma nodule of 50 mm diameter with absence of microvascular invasion and the non-tumoral liver showed histological features of NASH (SAF score: S1A2F3, NAS score: A3F3 and LAFSc:5) with absence of HBsAg and HBcAg. This case emphasizes the importance of long-term close surveillance by imaging of the graft even in the absence of viral recurrence and graft cirrhosis.