Two cases of colon LST in transplanted liver patients.

Long-life immunosuppressive therapy increases the risk of de novo tumors in liver transplant recipients by decreasing the immune surveillance against malignant cells and oncogenic viruses. However, no cases of colon precancerous lesions have been reported in these subjects. Patient n. 1, a 73 yrs old male treated with calcineurin and purine synthesis inhibitors, showed at a per-protocol colono-scopy a 3 cm laterally spreading tumor (LST). Patient n. 2, a 73 yrs old male treated with calcineurin inhibitors, showed at a screening colonoscopy an LST occupying one third of the lumen circumference. Both subjects were asymptomatic, had been transplanted 14 years before, and in both cases, lesions showed severe dysplasia. LSTs represent 17.2% of advanced colorectal neoplasia (CRC) and risk factors are multifactorial. Immunosuppression may play a role which is however not completely understood. Based on this report, surveillance colonoscopy in liver transplanted patients should be considered.