RESUMEN

We report on a 14-year-old girl who developed post-transplantation smooth muscle tumours (PTSMT) located in the spleen, lungs, liver, and central nervous system (CNS), 4 years after kidney transplantation. She was asymptomatic, and the disease was detected during the work-up for a urinary tract infection. Diagnosis was performed by the analysis of a tissue specimen, through the biopsy of a lung tumour, which revealed a proliferation of spindle-shaped cells which were positive for actin and vimentin. In situ hybridization studies were positive for Epstein-Barr virus, and her serologic status was negative prior to transplantation. We reduced immunosuppression by stopping mycophenolate and switching tacrolimus for sirolimus. After 18 months of follow-up, she remains asymptomatic, and the CNS tumour reduced its diameter from 24 × 21 mm to 14 × 13 mm. PTSMT should be considered in the differential diagnosis of transplanted patients who develop neoplastic complications associated with immunosuppression.