Focal nodular hyperplasia of the liver following hematopoietic SCT

Incidental hepatic regenerating nodules rarely occur after haematopoietic SCT (HSCT). Focal nodular hyperplasia (FNH) is one of these unusual benign tumors with characteristic imaging features. To determine the incidence and the outcome of FNH of the liver and improve the understanding of its pathogenesis, we prospectively surveyed a total of 138 patients who had undergone serial prospective pre- and post-transplantation evaluations of iron biomarkers, including ferritin and liver iron concentration assessed by magnetic resonance imaging (MRI). Seventeen patients with a median delay of 6.4 years (2.2-13.6) developed FNH of the liver. All were children at the time of transplantation. MR images were typical for FNH in 16 patients; only one patient needed a confirmatory biopsy. Sixteen had received a myeloablative conditioning; six received a BU-based preparation and 10 TBI. Three patients experienced sinusoidal obstruction syndrome. Neither complication nor malignant transformation has been reported to date. FNH of the liver seems to be a frequent delayed benign complication following HSCT, probably of iatrogenic vascular origin. Basic clinical and diagnostic imaging follow-up is warranted.