Genome-wide microsatellite analysis of focal nodular hyperplasia: a strong tool for the differential diagnosis of non-neoplastic liver nodule from hepatocellular carcinoma.

Allelic imbalance (AI), which represents certain chromosomal gains or losses, has been described in hepatocellular carcinoma (HCC), but the significance of AI analysis in focal nodular hyperplasia (FNH) has not been fully clarified. We hypothesized, therefore, that comprehensive allelotyping of FNH could be a useful tool for differentiating FNH from HCC. A 27-year-old man was admitted to the hospital because of general fatigue. A computed tomography (CT) scan disclosed a hepatic nodule 8 cm in diameter. No definite diagnosis was made after imaging or by biopsy before surgery. Macroscopically and microscopically, the surgical specimen showed typical features of FNH. Comprehensive microsatellite analysis was carried out with 382 microsatellite markers distributed throughout all chromosomes. To detect AI effectively, the cutoff value of the AI index was set at 0.70. Among the 382 microsatellite markers, 212 loci were informative, but no AI was detected. The absence of gross chromosomal alterations strongly suggested that the large nodule was FNH rather than HCC, in terms of its genetic background. The patient's subsequent clinical course revealed the nodule to be benign. The results suggest that this genome-wide microsatellite analysis is a useful tool for the differential diagnosis of non-neoplastic liver nodules from HCC. [ABSTRACT FROM AUTHOR]