BACKGROUND: Viral hepatitis C in children is milder than in adults. Patientswith tumors, because of immune deficits, seem to be at risk of rapid liver disease progression. Littleis known about the course of HCV and dual HBV-HCV infections in such patients. MATERIAL/METHODS: Thestudy assessed clinical courses of HCV and dual HBV-HCV infections in 249 children with tumors aged 1-18years, divided into four groups: with HCV infection - 53, HBV-HCV infection - 53, HBV only - 33 and infection-free- 110. RESULTS: Hepatitis C was often chronic - in 83.3% of patients with HCV and 77.3% of those withdual infection. Over 80% had no jaundice. Mean AlAT activity was the highest in the HCV group (149.2I202.7IU/l), lower in the dual infection group (123.3I148.1 IU/l; p<0.02), and the lowest in HBV (92.7±152.9 IU/l). Transaminasemia course in patients with HCV and dual HBV-HCV infections was most frequently fluctuating (50.9% and 45.3%, respectively). 52.8% of children with HCV demonstrated no advanced inflammatory lesions with invasion of the
lamina limitans, no marked fibrosis, and minimum changes in descriptive classification. In 92.3% of children with dual infections, inflammatory activity was mild or mean, with no fibrosis
in 61.5%, and persistent chronic inflammation predominant in descriptive classification(46.1%).
Conclusions: HCV and HBV-HCV infections in children with neoplastic diseases tend to take chronic forms, but their clinical course is mild with signs of severe inflammatory activity or hepatic
stroma remodeling observed on histopathology.

Keywords: Adolescent, Alanine Transaminase, bilirubin, Biopsy, Child, Child, Preschool, Comparative Study, Disease Progression, Follow-Up Studies, Hepatitis B, Hepatitis B, Chronic, Hepatitis C, Hepatitis C, Chronic, Incidence, Leukemia, Liver, Liver Cirrhosis, Neoplasms, Severity of Illness Index